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| | + | --[[User:Guastella|Guastella]] 20:48, 8 January 2008 (PST) |
| | Here is the article I mentioned in our meeting earlier today. | | Here is the article I mentioned in our meeting earlier today. |
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| | A CATALOG OF OPTICALLY SELECTED CORES | | A CATALOG OF OPTICALLY SELECTED CORES |
| | CHANG WON LEE AND PHILIP C. MYERS | | CHANG WON LEE AND PHILIP C. MYERS |
| − | Harvard-Smithsonian Center for Astrophysics, 60 Garden Street,MS 42, Cambridge, MA 02138; cwlee=cfa.harvard.edu, pmyers=cfa.harvard.edu
| + | [...] |
| − | Received 1998 October 7; accepted 1999 February 23
| |
| − | ABSTRACT
| |
| − | We present a new catalog of 406 dense cores optically selected by using the STScI Digitized Sky
| |
| − | Survey (DSS). In this catalog 306 cores have neither an embedded young stellar object (EYSO) nor a
| |
| − | preÈmain-sequence (PMS) star, 94 cores have EYSOs (one core has both an EYSO and a PMS star),
| |
| − | and six cores have PMS stars only. Our sample of dense cores in the catalog is fairly complete within a
| |
| − | category of northern Lynds class 5 and 6 clouds and southern Hartley et al. class A clouds, providing a
| |
| − | database useful for the systematic study of dense cores. Most of the cores listed in the catalog have
| |
| − | diameters between 0.05 and 0.36 pc with a mean of D0.24 pc. The sizes (D0.33 pc in the mean) of cores
| |
| − | with EYSOs are found to be usually larger than the sizes (D0.22 pc in the mean) of starless cores. The
| |
| − | typical mean gas density of the cores is D7]103 cm~3. Most of the cores are more likely elongated
| |
| − | than spherical (mean aspect ratio : D2.4). The ratio of the number of cores with EYSOs to the number of
| |
| − | starless cores for our sample is about 0.3, suggesting that the typical lifetime of starless cores is 0.3È1.6
| |
| − | Myr, about 3 times longer than the duration of the class 0 and class I phases. This lifetime is shorter
| |
| − | than expected from models of ambipolar di†usion, by factors of 2È44.
| |
| − | Subject headings : catalogs È ISM: clouds È stars : preÈmain-sequence
| |
| − | 1. INTRODUCTION
| |
| − | Low-mass stars are generally believed to form through
| |
| − | the inward gravitational collapse of ““ dense cores ÏÏ with
| |
| − | density Z a few 104 cm~3, which are expected to form via
| |
| − | ambipolar di†usion processes (Shu, Adams, & Lizano 1987;
| |
| − | Ciolek & Mouschovias 1995). However, the knowledge of
| |
| − | such simple processes in star formation is almost entirely
| |
| − | theoretical because there is still very little direct observational
| |
| − | support. It is therefore desirable to conduct
| |
| − | unbiased systematic surveys of dense cores to search for
| |
| − | evidence of core evolution and star-forming motion.
| |
| − | The optical dark cloud catalogs of Lynds (1962), Feitzinger
| |
| − | & Stu�we (1984), and Hartley et al. (1986, hereafter
| |
| − | HMSTG), based on visual inspection of optical sky survey
| |
| − | prints, have provided us the most basic and complete set of
| |
| − | sources for the study of star-forming regions, although these
| |
| − | catalogs themselves could not give accurate positions for a
| |
| − | systematic survey of dense cores because the positions of
| |
| − | dark regions were determined approximately by eye. Using
| |
| − | these catalogs has served as a basis for making more accurate
| |
| − | and detailed catalogs. For the northern hemisphere,
| |
| − | Myers, Linke, & Benson (1983, hereafter MLB) have collected
| |
| − | 90 small (angular size \5@) opaque spots through
| |
| − | visual inspection of the Palomar Sky Atlas prints to
| |
| − | conduct a systematic survey in 13CO, C18O (1È0) lines, and
| |
| − | later NH (Benson & Myers 1989, hereafter BM). Clemens & Barvai3nis (1988, hereafter CB) have also identiÐed 248
| |
| − | molecular clouds with optical sizes smaller than 10@ by procedures
| |
| − | similar to MLBÏs method. For the southern hemisphere,
| |
| − | Vilas-Boas, Myers, & Fuller (1994) selected 101
| |
| − | condensations with average optical size less than 7@ and
| |
| − | visual extinction greater than 2.5 mag from ESO J plates,
| |
| − | visual extinction maps (Hetem, Sanzovo, & Lepine 1988),
| |
| − | and the HMSTG catalog to observe them in the 13CO and
| |
| − | C18O (1È0) lines. Bourke, Hyland, & Robinson (1995a) have
| |
| − | compiled 169 Bok globuleÈlike small (\10@) dark clouds
| |
| − | from visual inspection of the SERC Schmidt survey J plates
| |
| − | primarily with the guidance of the HMSTG catalog and
| |
| − | observed all the cores in the ammonia (1,1) line (Bourke et
| |
| − | al. 1995b).
| |
| − | These e†orts resulted in an excellent database for the
| |
| − | observational study of low-mass star formation. However,
| |
| − | the samples given in these catalogs were limited to a few
| |
| − | regions, and many cores are still missing even toward the
| |
| − | searched area, so these previous studies are not complete.
| |
| − | Moreover, most opaque positions of the dark clouds in
| |
| − | these catalogs were determined by eye, so that positions are
| |
| − | not only very subjective but also not accurate enough for an
| |
| − | efficient survey in molecular lines.
| |
| − | Now, through the e†orts of the Space Telescope Science
| |
| − | Institute (STScI), the Digitized Sky Survey (DSS) data are
| |
| − | available for us. These data allow us to computerize the
| |
| − | selection of cores and accurately determine their positions.
| |
| − | With the guidance of the Lynds (1962) catalog for the northern
| |
| − | sky and the Hartley et al. (1986) catalog for the southern
| |
| − | sky, in addition to several reference catalogs that have been
| |
| − | used for numerous molecular line studies (see ° 2 for
| |
| − | detailed references), we created a new catalog of dense cores
| |
| − | using the STScI DSS. Our catalog presents the most complete
| |
| − | list of optically selected dense cores whose positions
| |
| − | were accurately measured within a few arcseconds. The
| |
| − | actual accuracy of positions is dependent only upon the
| |
| − | procedures for smoothing the data and centering the intensity
| |
| − | minima of the core.
| |
| − | In the following section we describe in detail how we
| |
| − | selected the cores. Then we analyze the statistics of the
| |
| − | physical parameters of our sample and discuss the implications
| |
| − | of core statistics for the present standard model
| |
| − | of isolated star formation. Finally we summarize our results
| |
| − | in ° 3.
| |
| − | 2. THE CATALOG
| |
| − | 2.1. Selection of Cores
| |
| − | Our method for the selection of cores is to image an area,
| |
| − | usually 0¡.5]0¡.5 and occasionally 1¡.0]1¡.0 around a reference
| |
| − | position, and to make a contour map of optical
| |
| − | 233
| |
| − | 234 LEE & MYERS
| |
| − | extinction to select the multiple local minimum positions of
| |
| − | intensity. For guiding reference positions, we used the following:
| |
| − | BM (NH peaks), Onishi et al. (1996 ; C18O peaks), Codella et al. (19937; NH peaks), Lemme et al. (1996; 3 NHpeaks), and Lynds (1962 ; every Lynds clouds with opacity 53
| |
| − | and 6) for northern clouds, and Vilas-Boas et al. (1994;
| |
| − | C18O peaks) and HMSTG (clouds with density class A) for
| |
| − | southern clouds (Table 1). Digitized data1 were retrieved
| |
| − | from the STScI DSS using the ““ getimage ÏÏ software
| |
| − | package provided by STScI. Image processing was conducted
| |
| − | with the IRAF software package2 (Tody 1993). An
| |
| − | accurate reading (within error of a few arcseconds) of coordinates
| |
| − | of local intensity minima in the contour map overlapped
| |
| − | in the gray image in IRAF was made possible by
| |
| − | browsing images in World Coordinate Space (Mink 1995)
| |
| − | with the ““ SAOimage ÏÏÈX11 window based image display
| |
| − | program (VanHilst 1990). However, the real accuracy of our
| |
| − | positions was dependent upon the grid size we used to make
| |
| − | smooth contours and center the intensity minima of the
| |
| − | core, usually about 15AÈ50A. In order to check the reliability
| |
| − | of our method, we compared our new positions with peak
| |
| − | positions of NH maps (with beam resolution of 87A) for 22 cores by BM. T3he di†erence [68@@^10@@ (mean^s.e.m.)]
| |
| − | between the two positions was found to be smaller than the
| |
| − | beam resolution of the NH maps, meaning that our method is fairly reliable for3 determining the intensity
| |
| − | minima positions of new cores.
| |
| − | Figure 1 shows one example of new core selection using
| |
| − | the dark cloud, L1622. This example is typical in that
| |
| − | several distinct intensity minima are obtained for each reference
| |
| − | position. In total, we examined 250 reference positions
| |
| − | (Table 1) and identiÐed 406 local maxima of optical extinction
| |
| − | (Table 2), which we call cores. For all sources, we
| |
| − | searched the IRAS Point Source Catalog using the ““ riras ÏÏ
| |
| − | package (D. J.Mink 1998, private communication) to determine
| |
| − | which sources have embedded IRAS point sources. In
| |
| − | the search, we assumed the IRAS point source to be an
| |
| − | ““ embedded ÏÏ young stellar object (EYSO) when it satisÐes
| |
| − | all of the following criteria :
| |
| − | 1. There should be detections in at least two of the four
| |
| − | IRAS wavelength bands.
| |
| − | 2. The detected Ñuxes (F) should be greater in the longer
| |
| − | wavelength. However, IRAS point sources with F100km\
| |
| − | F60km or or were con- , F100km\F25kmsidered to be EYSO, s Fas100kmlo\ngF12akms F60km[
| |
| − | F25km[F12km.
| |
| − | 3. The projected position of the IRAS source on the sky
| |
| − | should be enclosed by the contour of the least extinction
| |
| − | level of core in the optical image.
| |
| − | 1 Images from the northern plates (POSS) were based on photographic
| |
| − | data of the National Geographic SocietyÈPalomar Geographic Society to
| |
| − | the California Institute of Technology, and images from the southern
| |
| − | plates (SERC-J) were based on photographic data obtained using the UK
| |
| − | Schmidt Telescope. The plates were processed into the present compressed
| |
| − | digital form with their permission. The UK Schmidt Telescope was operated
| |
| − | by the Royal Observatory Edinburgh, with funding from the UK
| |
| − | Science and Engineering Research Council, until 1988 June, and thereafter
| |
| − | by the Anglo-Australian Observatory. The Digitized Sky Survey was produced
| |
| − | at the Space Telescope Science Institute under US government grant
| |
| − | NAGW-2166.
| |
| − | 2 IRAF is distributed by the National Optical Astronomy Observatories,
| |
| − | which are operated by the Association of Universities for Research
| |
| − | in Astronomy, Inc., under cooperative agreement with the National
| |
| − | Science Foundation.
| |
| − | With these criteria, we searched all cores to determine
| |
| − | whether there are EYSOs within a box with a size of 2 times
| |
| − | the geometric mean of the FWHM of a core. The FWHM
| |
| − | of the core was obtained from an extinction contour map of
| |
| − | the core as described in the next section. We found 94
| |
| − | sources with EYSOs and 306 cores without EYSOs. Our
| |
| − | criteria are very similar to those of BMbut di†er from those
| |
| − | of Beichman et al. (1986) and Wood, Myers, & Daugherty
| |
| − | (1994) in that ours were designed to preferentially select
| |
| − | embedded protostars (class 0 and class I YSOs) and therefore
| |
| − | not to include preÈmain-sequence (PMS) stars. To Ðnd
| |
| − | a possible PMS star, we used color-color diagram criteria in
| |
| − | the 12, 25, and 60 km IRAS bands of Weintraub (1990) :
| |
| − | [2.00\log (l12F12 and /l25 F25)/log (l12/l25)\1.35
| |
| − | [1.75\log (l25F25 Five /l60 F60)/log (l25/l60)\2.20.
| |
| − | cores were found to have possible PMS stars. We also
| |
| − | searched the catalog of PMS stars by Herbig & Bell (1988)
| |
| − | in which PMS stars were identiÐed by optical spectroscopic
| |
| − | data. From this search two more sources were found to
| |
| − | include PMS stars within their projected extents. Thus we
| |
| − | believe that seven sources may have PMS stars. We note
| |
| − | that one of seven contains EYSO as well.
| |
| − | In summary, of 406 identiÐed cores, 306 were found to
| |
| − | have neither an EYSO nor a PMS star, 94 were found to
| |
| − | have EYSOs (one core has both an EYSO and a PMS star),
| |
| − | and six to have a PMS star only. Henceforth we call the 306
| |
| − | cores with neither an EYSO nor a PMS star ““ starless
| |
| − | cores. ÏÏ In Table 2, column (9), the starless cores are marked
| |
| − | as N and cores with EYSOs as Y, cores with a PMS star are
| |
| − | marked as PM or PM* for a PMS star known by optical
| |
| − | spectroscopy (Herbig & Bell 1988), and cores with both an
| |
| − | EYSO and a PMS star are marked as Y/PM. The IRAS
| |
| − | point sources and the PMS stars believed to be associated
| |
| − | with our optically selected cores are listed in Table 3.
| |
| − | 2.2. Statistics of Physical Parameters of Cores
| |
| − | In this section we discuss the statistics of the physical
| |
| − | parameters of cores. Our sample statistics are believed to be
| |
| − | representative of the core properties since the cores were
| |
| − | selected from Lynds class 5 and 6 and HMSTGÏs class A,
| |
| − | which, taken together, comprise a nearly complete set of the
| |
| − | densest and the most opaque clouds in the sky.
| |
| − | We present several physical parameters of the optically
| |
| − | selected cores in Table 2. The sizes of the major axis (a in
| |
| − | col. [5] of Table 2) and the minor axis (b in col. [6] of Table
| |
| − | 2), and position angle (PA in col. [8] of Table 2) of the
| |
| − | FWHM of the cores were approximately measured by an
| |
| − | ellipse template, ruler, and protractor. The minus and plus
| |
| − | signs in column (8) mean clockwise and counterclockwise
| |
| − | with respect to equatorial north, respectively. The largest
| |
| − | errors for these parameters are from the uncertainties in the
| |
| − | selection of the background level of the core that determines
| |
| − | the size of the FWHM of the core and in the eye Ðtting of
| |
| − | the ellipse template to the core. The errors obtained by
| |
| − | repeating measurements are usually within about 10% of
| |
| − | the size in the size measurement and within about 5¡ in the
| |
| − | PA measurement. For the sources that are not elliptical in
| |
| − | shape, their ““ equivalent ÏÏ diameters (R in col. [7] of Table
| |
| − | 2) were measured. The equivalent diameter of a core is
| |
| − | deÐned as 2](A/n)0.5, where A is the area within the
| |
| − | FWHM contour of the core. Following are our results and
| |
| − | discussion on the statistics of these physical parameters.
| |
| − | TABLE 1
| |
| − | SEARCHED REFERENCE REGIONS
| |
| − | Regiona R.A. (1950) Decl. (1950) Referenceb Nc Regiona R.A. (1950) Decl. (1950) Referenceb Nc
| |
| − | L1291 . . . . . . . . . . . . . . . . 00 39 47.6 61 44 35 Lynds 1 L260 . . . . . . . . . . . . . . . . . 16 44 22.3 [09 30 02 BM 1
| |
| − | L1333 . . . . . . . . . . . . . . . . 02 21 10.2 75 13 32 Lynds 1 L158* . . . . . . . . . . . . . . . 16 44 42.0 [13 54 03 BM 6
| |
| − | L1355 . . . . . . . . . . . . . . . . 02 48 41.4 68 43 36 Lynds 1 L204BC* . . . . . . . . . . . . 16 44 51.0 [12 09 00 BM 6
| |
| − | L1358 . . . . . . . . . . . . . . . . 02 51 00.0 69 10 00 Lynds 2 L191 . . . . . . . . . . . . . . . . . 16 44 59.2 [12 35 31 BM 2
| |
| − | L1450D . . . . . . . . . . . . . 03 25 18.8 30 53 02 BM 1 L255 . . . . . . . . . . . . . . . . . 16 45 01.9 [09 48 32 Lynds 2
| |
| − | B5 . . . . . . . . . . . . . . . . . . . . 03 45 16.3 32 44 59 BM 1 L234 . . . . . . . . . . . . . . . . . 16 45 38.0 [10 56 00 BM 3
| |
| − | CB 17 . . . . . . . . . . . . . . . 04 00 35.0 56 48 00 Le 1 L162 . . . . . . . . . . . . . . . . . 16 46 40.0 [14 04 10 Lynds 2
| |
| − | L1498 . . . . . . . . . . . . . . . . 04 07 50.0 25 02 13 BM 1 L63 . . . . . . . . . . . . . . . . . . 16 47 21.0 [18 01 00 BM 4
| |
| − | L1495 . . . . . . . . . . . . . . . . 04 15 18.0 28 25 00 ON 2 L141 . . . . . . . . . . . . . . . . . 16 48 03.1 [15 16 54 Lynds 3
| |
| − | L1506B . . . . . . . . . . . . . . 04 16 03.9 25 13 01 Lynds 1 L129 . . . . . . . . . . . . . . . . . 16 52 18.4 [16 17 10 Lynds 1
| |
| − | L1506A . . . . . . . . . . . . . . 04 20 18.0 24 54 00 ON 1 L122 . . . . . . . . . . . . . . . . . 16 52 22.4 [16 42 03 Lynds 1
| |
| − | L1399 . . . . . . . . . . . . . . . . 04 20 27.0 54 51 00 Lynds 3 L146 . . . . . . . . . . . . . . . . . 16 53 37.0 [15 55 00 Lynds 1
| |
| − | L1521B . . . . . . . . . . . . . . 04 20 48.0 26 31 40 BM 2 CB 68 . . . . . . . . . . . . . . . 16 53 52.0 [16 00 00 Le 3
| |
| − | B213-7 . . . . . . . . . . . . . . . 04 22 24.0 26 24 00 ON 1 DC 3504]44 . . . . . . . 16 59 40.9 [34 20 44 HMSTG 1
| |
| − | B217 . . . . . . . . . . . . . . . . . 04 24 42.5 26 11 13 BM 2 L111 . . . . . . . . . . . . . . . . . 17 11 59.5 [20 27 15 Lynds 1
| |
| − | L1521 . . . . . . . . . . . . . . . . 04 25 36.0 26 45 00 ON 2 L100 . . . . . . . . . . . . . . . . . 17 13 07.6 [20 54 04 Lynds 1
| |
| − | L1407 . . . . . . . . . . . . . . . . 04 25 37.6 54 07 35 Lynds 1 L173 . . . . . . . . . . . . . . . . . 17 14 25.4 [18 27 45 Lynds 1
| |
| − | L1400AK . . . . . . . . . . . 04 25 47.0 54 48 00 BM 4 L1768 . . . . . . . . . . . . . . . 17 17 00.0 [26 49 00 Lynds 2
| |
| − | L1521E . . . . . . . . . . . . . . 04 26 17.0 26 07 47 BM 1 L1773 . . . . . . . . . . . . . . . 17 18 08.4 [26 50 46 Lynds 1
| |
| − | L1524 . . . . . . . . . . . . . . . . 04 26 22.0 24 26 30 ON 4 L1774 . . . . . . . . . . . . . . . 17 19 32.1 [27 02 25 Lynds 1
| |
| − | L1445 . . . . . . . . . . . . . . . . 04 28 28.8 46 31 01 Lynds 1 B68 . . . . . . . . . . . . . . . . . . 17 20 23.0 [23 47 13 BM 3
| |
| − | L1551S . . . . . . . . . . . . . . 04 28 40.0 18 01 52 BM 2 DC 3463[41 . . . . . . . 17 22 40.3 [42 37 01 HMSTG 1
| |
| − | B18-2 . . . . . . . . . . . . . . . . 04 29 00.0 24 35 53 ON 1 DC 3479[44 . . . . . . . 17 28 52.7 [41 32 37 HMSTG 1
| |
| − | TMC 2 . . . . . . . . . . . . . . 04 29 13.0 24 20 14 BM 4 L425 . . . . . . . . . . . . . . . . . 17 44 15.4 [04 34 07 Lynds 1
| |
| − | L1536B . . . . . . . . . . . . . . 04 29 54.0 22 52 00 ON 2 DC 3475[80 . . . . . . . 17 44 26.1 [43 42 02 HMSTG 1
| |
| − | L1536A . . . . . . . . . . . . . . 04 30 26.0 22 36 10 BM 1 L392 . . . . . . . . . . . . . . . . . 17 50 24.3 [08 26 43 Lynds 1
| |
| − | B18-3 . . . . . . . . . . . . . . . . 04 30 53.7 24 05 09 ON 1 L421 . . . . . . . . . . . . . . . . . 17 51 38.9 [05 46 02 Lynds 1
| |
| − | B18-4 . . . . . . . . . . . . . . . . 04 32 36.0 24 02 00 ON 2 L460 . . . . . . . . . . . . . . . . . 17 55 24.4 [03 46 24 Lynds 1
| |
| − | L1527 . . . . . . . . . . . . . . . . 04 36 00.0 26 10 00 Lynds 2 L432 . . . . . . . . . . . . . . . . . 17 55 46.2 [05 43 45 Lynds 1
| |
| − | L1534 . . . . . . . . . . . . . . . . 04 36 31.2 25 35 56 BM 1 L468 . . . . . . . . . . . . . . . . . 17 57 38.0 [03 30 03 Lynds 1
| |
| − | CB 22 . . . . . . . . . . . . . . . 04 37 25.0 29 48 57 Le 1 L462 . . . . . . . . . . . . . . . . . 18 04 48.0 [04 42 08 Lynds 1
| |
| − | TMC 1 . . . . . . . . . . . . . . 04 38 19.0 25 45 30 BM 2 L108 . . . . . . . . . . . . . . . . . 18 07 08.0 [28 18 41 Lynds 1
| |
| − | L1507A . . . . . . . . . . . . . . 04 39 29.0 29 38 07 CO 2 L422 . . . . . . . . . . . . . . . . . 18 09 20.0 [08 04 46 Lynds 1
| |
| − | L1507B . . . . . . . . . . . . . . 04 39 53.4 29 38 25 Lynds 3 L436-8 . . . . . . . . . . . . . . 18 11 39.1 [07 16 18 Lynds 2
| |
| − | L1426 . . . . . . . . . . . . . . . . 04 43 17.5 52 59 03 Lynds 1 L323 . . . . . . . . . . . . . . . . . 18 12 39.1 [18 11 47 Lynds 1
| |
| − | L1517 . . . . . . . . . . . . . . . . 04 52 07.2 30 33 18 BM 4 L490-2 . . . . . . . . . . . . . . 18 12 30.0 [03 46 40 Lynds 2
| |
| − | L1512 . . . . . . . . . . . . . . . . 05 00 54.4 32 39 00 BM 1 CB 130 . . . . . . . . . . . . . . 18 13 38.0 [02 33 52 Le 3
| |
| − | L1544 . . . . . . . . . . . . . . . . 05 01 14.0 25 07 00 BM 3 L328 . . . . . . . . . . . . . . . . . 18 14 06.7 [18 03 54 Lynds 1
| |
| − | L1523 . . . . . . . . . . . . . . . . 05 03 02.7 31 37 30 Lynds 1 L429 . . . . . . . . . . . . . . . . . 18 14 49.7 [08 15 50 Lynds 4
| |
| − | CB 28 . . . . . . . . . . . . . . . 05 03 51.0 [04 00 00 Le 1 L483 . . . . . . . . . . . . . . . . . 18 15 00.0 [04 40 00 Lynds 2
| |
| − | L1552 . . . . . . . . . . . . . . . . 05 14 34.9 26 01 17 Lynds 1 L466 . . . . . . . . . . . . . . . . . 18 17 04.5 [06 07 36 Lynds 1
| |
| − | L1582A . . . . . . . . . . . . . . 05 28 30.0 12 28 20 BM 1 L451 . . . . . . . . . . . . . . . . . 18 19 12.3 [07 14 11 Lynds 1
| |
| − | B35A . . . . . . . . . . . . . . . . 05 41 45.3 09 07 40 BM 1 L539 . . . . . . . . . . . . . . . . . 18 21 24.0 [01 06 00 Lynds 2
| |
| − | L1622 . . . . . . . . . . . . . . . . 05 52 00.0 01 51 00 Lynds 2 L416 . . . . . . . . . . . . . . . . . 18 22 46.2 [10 41 26 Lynds 1
| |
| − | L1621 . . . . . . . . . . . . . . . . 05 53 02.0 02 10 27 Lynds 2 L406 . . . . . . . . . . . . . . . . . 18 22 50.5 [11 49 11 Lynds 1
| |
| − | CB 37 . . . . . . . . . . . . . . . 05 57 24.0 31 39 26 Le 1 L423 . . . . . . . . . . . . . . . . . 18 25 03.9 [10 16 08 Lynds 1
| |
| − | L1574 . . . . . . . . . . . . . . . . 06 04 48.0 18 30 00 Lynds 1 L411 . . . . . . . . . . . . . . . . . 18 25 07.9 [11 29 15 Lynds 1
| |
| − | L1645 . . . . . . . . . . . . . . . . 06 05 16.0 [05 33 00 Lynds 1 L503 . . . . . . . . . . . . . . . . . 18 26 49.5 [04 40 45 Lynds 1
| |
| − | L1578 . . . . . . . . . . . . . . . . 06 05 33.0 18 07 00 BM 2 L443 . . . . . . . . . . . . . . . . . 18 30 00.0 [09 10 00 Lynds 2
| |
| − | CB 45 . . . . . . . . . . . . . . . 06 06 00.0 17 50 52 Le 1 L239 . . . . . . . . . . . . . . . . . 18 30 11.5 [26 04 16 Lynds 1
| |
| − | L1633 . . . . . . . . . . . . . . . . 06 22 00.0 03 30 00 Lynds 1 L588 . . . . . . . . . . . . . . . . . 18 33 00.0 [00 35 00 Lynds 1
| |
| − | DC 2592[132 . . . . . . 07 29 30.0 [46 51 00 HMSTG 2 L495 . . . . . . . . . . . . . . . . . 18 36 32.6 [06 41 06 Lynds 1
| |
| − | DC 2555[48 . . . . . . . 08 03 46.1 [39 00 10 HMSTG 1 L648 . . . . . . . . . . . . . . . . . 18 37 15.0 12 41 50 Lynds 2
| |
| − | V13-14. . . . . . . . . . . . . . . 08 07 39.0 [35 55 54 VMP 4 L530D . . . . . . . . . . . . . . 18 47 18.0 [04 53 20 BM 3
| |
| − | DC 2573[25 . . . . . . . 08 15 23.0 [39 43 36 HMSTG 2 L549 . . . . . . . . . . . . . . . . . 18 59 29.8 [05 23 08 Lynds 1
| |
| − | DC 2660[75 . . . . . . . 08 19 53.7 [49 41 10 HMSTG 2 L567 . . . . . . . . . . . . . . . . . 19 01 32.0 [04 30 00 BM 1
| |
| − | DC 2674[75 . . . . . . . 08 24 17.0 [50 52 12 HMSTG 2 B133 . . . . . . . . . . . . . . . . . 19 03 25.3 [06 57 20 BM 1
| |
| − | DC 2672[72 . . . . . . . 08 25 03.5 [50 30 11 HMSTG 1 CB 180 (L531) . . . . . . 19 03 31.0 [06 58 07 Le 1
| |
| − | DC 2676[60 . . . . . . . 08 32 38.0 [50 08 00 HMSTG 2 L581 . . . . . . . . . . . . . . . . . 19 04 55.5 [03 59 32 Lynds 1
| |
| − | DC 2694]30 . . . . . . . 09 20 28.7 [45 35 05 HMSTG 1 L709 . . . . . . . . . . . . . . . . . 19 11 37.3 16 22 01 Lynds 1
| |
| − | DC 2695]40 . . . . . . . 09 24 18.1 [44 58 32 HMSTG 1 DC 13[205 . . . . . . . . 19 13 12.4 [36 42 20 HMSTG 1
| |
| − | DC 2742[04 . . . . . . . 09 27 05.5 [51 23 14 HMSTG 1 L763 . . . . . . . . . . . . . . . . . 19 16 45.9 23 21 45 Lynds 1
| |
| − | DC 2962[158 . . . . . . 10 49 28.9 [76 48 59 HMSTG 1 L730 . . . . . . . . . . . . . . . . . 19 17 40.5 19 51 09 Lynds 2
| |
| − | DC 2965[157 . . . . . . 10 55 31.7 [76 48 52 HMSTG 1 L655 . . . . . . . . . . . . . . . . . 19 17 47.2 08 23 33 Lynds 1
| |
| − | DC 29103[35 . . . . . . 10 57 12.9 [63 26 49 HMSTG 1 L673-1-10 . . . . . . . . . . . 19 18 45.0 11 22 00 Lynds 10
| |
| − | TABLE 1ÈContinued
| |
| − | Regiona R.A. (1950) Decl. (1950) Referenceb Nc Regiona R.A. (1950) Decl. (1950) Referenceb Nc
| |
| − | DC 2971[161 . . . . . . 11 01 04.0 [77 25 48 HMSTG 2 L673-11 . . . . . . . 19 18 45.0 11 05 00 Lynds 1
| |
| − | DC 2972[151 . . . . . . 11 09 09.7 [76 37 16 HMSTG 1 L673-12 . . . . . . . 19 18 45.0 10 50 00 Lynds 3
| |
| − | DC 2983[131 . . . . . . 11 37 59.1 [75 00 00 HMSTG 1 L771 . . . . . . . . . . . 19 18 46.3 23 25 13 Lynds 1
| |
| − | DC 2977[28 . . . . . . . 11 59 07.2 [64 52 15 HMSTG 1 L684 . . . . . . . . . . . 19 19 16.1 12 23 25 Lynds 1
| |
| − | Mu 4 . . . . . . . . . . . . . . . . 12 21 29.0 [71 35 56 VMP 1 L677 . . . . . . . . . . . 19 19 40.0 11 25 00 Lynds 4
| |
| − | DC 3002[35 . . . . . . . 12 21 30.2 [65 55 26 HMSTG 1 L774 . . . . . . . . . . . 19 21 15.0 23 20 00 Lynds 2
| |
| − | Mu 8 . . . . . . . . . . . . . . . . 12 26 39.0 [70 54 04 VMP 2 L769 . . . . . . . . . . . 19 22 15.0 23 00 00 Lynds 4
| |
| − | DC 3007[10 . . . . . . . 12 28 50.6 [63 28 02 HMSTG 1 L698 . . . . . . . . . . . 19 23 37.5 12 59 48 Lynds 1
| |
| − | DC 3023[177 . . . . . . 12 32 17.0 [80 16 18 HMSTG 3 L778 . . . . . . . . . . . 19 25 16.0 23 40 19 Lynds 4
| |
| − | DC 3025[175 . . . . . . 12 37 03.2 [80 03 39 HMSTG 1 B335 . . . . . . . . . . . 19 34 33.3 07 27 00 BM 1
| |
| − | DC 3026[159 . . . . . . 12 41 21.4 [78 31 56 HMSTG 1 L694 . . . . . . . . . . . 19 38 18.0 10 54 44 Lynds 3
| |
| − | DC 3029[141 . . . . . . 12 46 14.9 [76 40 50 HMSTG 1 L758 . . . . . . . . . . . 19 44 12.8 18 54 47 Lynds 1
| |
| − | Ch 5 . . . . . . . . . . . . . . . . . 12 46 38.7 [76 41 04 VMP 1 L880 . . . . . . . . . . . 20 11 49.4 40 03 59 Lynds 1
| |
| − | DC 3030[143 . . . . . . 12 49 14.6 [76 56 33 HMSTG 1 L1152 . . . . . . . . . 20 35 24.0 67 43 53 BM 1
| |
| − | Ch 17 . . . . . . . . . . . . . . . . 12 56 14.0 [77 00 00 VMP 4 L1041 . . . . . . . . . 20 36 05.5 57 33 36 Lynds 1
| |
| − | DC 3036[145 . . . . . . 12 59 11.0 [77 06 44 HMSTG 2 L922 . . . . . . . . . . . 20 36 22.0 44 19 07 Lynds 1
| |
| − | DC 3037[148 . . . . . . 13 01 39.7 [77 26 49 HMSTG 2 L917 . . . . . . . . . . . 20 38 30.0 43 58 00 Lynds 2
| |
| − | DC 3037[150 . . . . . . 13 01 55.0 [77 36 42 HMSTG 2 L1049 . . . . . . . . . 20 40 00.0 57 20 00 Lynds 2
| |
| − | DC 3038[142 . . . . . . 13 03 36.4 [76 44 48 HMSTG 1 L1148 . . . . . . . . . 20 40 00.0 67 11 00 BM 2
| |
| − | DC 3162]51 . . . . . . . 14 22 33.6 [55 07 04 HMSTG 1 L896 . . . . . . . . . . . 20 40 28.8 39 42 22 Lynds 2
| |
| − | DC 3148[51 . . . . . . . 14 44 23.4 [65 04 41 HMSTG 1 L1155C . . . . . . . 20 43 00.0 67 41 44 BM 3
| |
| − | DC 3230]40 . . . . . . . 15 07 35.6 [53 06 36 HMSTG 1 L915 . . . . . . . . . . . 20 43 23.0 42 58 52 Lynds 1
| |
| − | DC 3382]164 . . . . . . 15 37 21.0 [34 29 18 HMSTG 2 L1082C . . . . . . . 20 49 36.0 60 07 40 BM 3
| |
| − | DC 3272]18 . . . . . . . 15 38 33.4 [52 38 36 HMSTG 1 L1082AB . . . . . . 20 52 20.7 60 03 14 BM 2
| |
| − | DC 3388]165 . . . . . . 15 39 25.0 [33 52 00 HMSTG 6 L981 . . . . . . . . . . . 20 58 38.0 50 05 09 Lynds 3
| |
| − | DC 3392]161 . . . . . . 15 42 01.0 [34 08 00 HMSTG 4 L971 . . . . . . . . . . . 20 59 15.8 49 07 34 Lynds 2
| |
| − | DC 3389]151 . . . . . . 15 43 49.0 [35 04 30 HMSTG 2 L1174 . . . . . . . . . 20 59 46.3 68 01 04 BM 1
| |
| − | L134A . . . . . . . . . . . . . . . 15 50 58.1 [04 26 36 BM 1 L1172A . . . . . . . 21 01 45.0 67 35 13 BM 3
| |
| − | L183 . . . . . . . . . . . . . . . . . 15 51 35.7 [02 40 54 BM 1 L1063 . . . . . . . . . 21 06 44.6 56 06 09 Lynds 1
| |
| − | DC 3386]119 . . . . . . 15 53 26.0 [37 41 12 HMSTG 2 B361 . . . . . . . . . . . 21 10 35.0 47 12 01 BM 2
| |
| − | DC 3356]82 . . . . . . . 15 54 42.3 [42 26 57 HMSTG 1 L1125 . . . . . . . . . 21 14 07.0 61 27 10 Lynds 2
| |
| − | DC 3391]117 . . . . . . 15 55 22.0 [37 31 12 HMSTG 2 L944 . . . . . . . . . . . 21 15 54.0 43 05 41 Lynds 3
| |
| − | DC 3364]82 . . . . . . . 15 58 00.0 [41 50 00 HMSTG 2 L952-3 . . . . . . . . 21 18 51.0 43 13 00 Lynds 3
| |
| − | DC 3369]83 . . . . . . . 15 59 05.3 [41 31 30 HMSTG 1 L1021 . . . . . . . . . 21 20 34.8 50 50 17 Lynds 1
| |
| − | DC 3386]95 . . . . . . . 16 01 09.6 [39 29 37 HMSTG 1 L1014-1 . . . . . . . 21 22 20.6 49 56 52 Lynds 2
| |
| − | DC 3346]46 . . . . . . . 16 02 54.2 [45 46 25 HMSTG 1 L1099 . . . . . . . . . 21 34 27.9 57 13 18 Lynds 2
| |
| − | DC 3394]95 . . . . . . . 16 04 27.0 [39 04 06 HMSTG 1 L973 . . . . . . . . . . . 21 35 16.3 43 06 57 Lynds 1
| |
| − | DC 3376]76 . . . . . . . 16 04 58.6 [41 32 54 HMSTG 1 L1111 . . . . . . . . . 21 38 53.6 57 34 24 Lynds 1
| |
| − | DC 3397]92 . . . . . . . 16 06 45.0 [38 58 24 HMSTG 3 L1121 . . . . . . . . . 21 39 10.0 58 02 33 Lynds 1
| |
| − | DC 3381]71 . . . . . . . 16 07 59.4 [41 34 19 HMSTG 3 L1103 . . . . . . . . . 21 40 40.6 56 30 00 Lynds 2
| |
| − | DC 3402]90 . . . . . . . 16 08 01.0 [38 53 49 HMSTG 1 L1113 . . . . . . . . . 21 42 56.7 56 56 25 Lynds 2
| |
| − | DC 3369]51 . . . . . . . 16 10 18.3 [43 53 34 HMSTG 1 L1031C . . . . . . . 21 44 35.6 47 04 20 BM 1
| |
| − | DC 3420]94 . . . . . . . 16 14 28.7 [37 23 52 HMSTG 1 L1139 . . . . . . . . . 21 53 47.3 58 20 14 Lynds 2
| |
| − | DC 3412]65 . . . . . . . 16 21 44.4 [39 52 38 HMSTG 1 L1143 . . . . . . . . . 21 57 03.0 58 42 25 Lynds 1
| |
| − | L1681A* . . . . . . . . . . . . 16 23 59.0 [24 27 32 BM 1 L1166 . . . . . . . . . 22 03 46.7 59 19 07 Lynds 1
| |
| − | L1681B . . . . . . . . . . . . . . 16 24 33.8 [24 36 47 BM 1 L1164 . . . . . . . . . 22 05 07.7 58 51 15 Lynds 1
| |
| − | L1696AB . . . . . . . . . . . . 16 25 30.0 [24 12 32 BM 3 L1235 . . . . . . . . . 22 14 41.4 73 10 00 BM 1
| |
| − | L1704 . . . . . . . . . . . . . . . . 16 27 50.0 [23 34 37 BM 2 L1195 . . . . . . . . . 22 25 18.1 61 01 06 Lynds 1
| |
| − | L1757 . . . . . . . . . . . . . . . . 16 29 01.9 [19 35 24 Lynds 2 L1221 . . . . . . . . . 22 26 38.4 68 45 48 Lynds 1
| |
| − | L1709BC* . . . . . . . . . . 16 29 16.0 [23 51 12 BM 4 L1185 . . . . . . . . . 22 27 27.6 58 53 30 Lynds 1
| |
| − | L1689AB* . . . . . . . . . . 16 30 10.5 [24 37 57 BM 6 L1251A . . . . . . . 22 29 03.3 74 58 51 BM 2
| |
| − | DC 3387]18 . . . . . . . 16 30 33.3 [44 54 53 HMSTG 1 L1197 . . . . . . . . . 22 35 08.0 58 41 46 Lynds 1
| |
| − | L43 . . . . . . . . . . . . . . . . . . 16 31 27.7 [15 41 40 BM 3 L1251 . . . . . . . . . 22 36 26.0 74 54 46 Lynds 1
| |
| − | DC 3460]78 . . . . . . . 16 33 32.0 [35 31 06 HMSTG 2 L1229 . . . . . . . . . 23 12 16.8 61 46 47 Lynds 1
| |
| − | DC 3464]79 . . . . . . . 16 34 13.4 [35 08 26 HMSTG 1 L1234 . . . . . . . . . 23 15 12.0 62 10 00 Lynds 1
| |
| − | DC 3463]78 . . . . . . . 16 34 26.8 [35 21 54 HMSTG 1 CB 243 . . . . . . . . 23 23 00.0 63 20 00 Le 1
| |
| − | L121 . . . . . . . . . . . . . . . . . 16 36 41.0 [13 59 21 Lynds 1 L1262A . . . . . . . 23 23 32.2 74 01 45 BM 1
| |
| − | L1782 . . . . . . . . . . . . . . . . 16 39 13.2 [19 36 22 Lynds 2 CB 246 . . . . . . . . 23 54 12.0 58 17 47 Le 1
| |
| − | DC 3393[03 . . . . . . . 16 42 30.0 [45 54 54 HMSTG 1 L1263 . . . . . . . . . 23 54 54.2 64 32 27 Lynds 1
| |
| − | DC 3405]05 . . . . . . . 16 43 05.8 [44 26 04 HMSTG 1 L1271 . . . . . . . . . 23 59 15.3 67 01 48 Lynds 4
| |
| − | NOTE.ÈUnits of right ascension are hours, minutes, and seconds, and units of declination are degrees, arcminutes, and arcseconds.
| |
| − | a Searched size of all regions is 30@]30@ except for the Ðve regions marked with an asterisk behind the name of the region, whose searched area is
| |
| − | 60@]60@.
| |
| − | b REFERENCES.ÈLynds, Lynds 1962; BM, Benson & Myers 1989; Le, Lemme et al. 1996; ON, Onishi et al. 1996; CO, Codella et al. 1997; HMSTG,
| |
| − | Hartley et al. 1986; VMP, Vilas-Boas et al. 1994.
| |
| − | c Number of cores selected in each reference region.
| |
| − | L1622
| |
| − | A
| |
| − | B
| |
| − | OPTICALLY SELECTED CORES 237
| |
| − | FIG. 1.ÈAn example (for L1622) of how to select the local minimum positions of the intensity in a cloud by its optical extinction using an image extracted
| |
| − | from the STScI Digitized Sky Survey. The area of the image is and the coordinate of 0¡.5]0¡.5 the center is (a, d) 52m 01¡ 51@ 00@@), which was 1950.0\(5h 00s.0,
| |
| − | changed from the Lynds (1962) position to shift the cloud into a central position in the image. The smooth contours are overlaid on the gray-scale image to
| |
| − | enable identiÐcation of two local minima (A and B) of intensity. The smoothing length for the contours in this case is 30A. The regions with the locally lowest
| |
| − | or highest intensity are marked with L and H, respectively. The numeric values below the characters are data values by DSS that are proportional to
| |
| − | photographic densities.
| |
| − | 2.2.1. T he Darkness Contrast of Cores
| |
| − | In Table 2, column (10), we give an indication of a darkness
| |
| − | contrast (DC) of the dark core to the background in
| |
| − | the DSS image. This contrast was calculated according to
| |
| − | (IB[IC)/IB, where IB and IC are the data values (DN) by
| |
| − | DSS (that are on a scale of photographic density [c] in the
| |
| − | expression c\DN/6553.4 [Postman 1996]) for the background
| |
| − | and the core, respectively. The IB and IC values were
| |
| − | approximately determined by using a cut-proÐle of the data
| |
| − | values crossing the core. The IB and IC would correspond to
| |
| − | a constantly Ñat level and a minimum level of the proÐle,
| |
| − | respectively. Figure 2 shows an example of how we adopted
| |
| − | IB and IC for L1622. This cut-proÐle is the one crossing two
| |
| − | intensity minima of L1622A and L1622B.
| |
| − | According to this value of the DC, we classiÐed cores into
| |
| − | four quartiles, 1 being the least dark to 4 the most dark so
| |
| − | that each group contains 25% of total number of cores. It is
| |
| − | noted that the Lynds 6 and HMSTG A clouds more likely
| |
| − | consist of cores with a DC of 3 or 4, while Lynds 5 clouds
| |
| − | more likely have cores with a DC of 1 or 2 (Fig. 3). However
| |
| − | we also note that if the dark cores are located at the dark
| |
| − | background, the DC values tend to have a low value. This
| |
| − | explains why many Lynds 6 cores also have a DC value of 1
| |
| − | in Figure 3.
| |
| − | 2.2.2. T he Size and the AspectRatio of Cores
| |
| − | For evaluation of these properties, we do not consider
| |
| − | cores with more than two peaks in the contour map because
| |
| − | of ambiguity in the size information of such cores, but we do
| |
| − | consider cores with only one peak in the map whose size
| |
| − | and aspect ratio can be better determined. The distribution
| |
| − | of the apparent angular size of cores is shown with the
| |
| − | geometric mean (ab)0.5 of cores in Figure 4, indicating that
| |
| − | most of the cores (D70%) have angular size between 1@ and
| |
| − | TABLE 2
| |
| − | OPTICALLY SELECTED CORES
| |
| − | a b R PA Distance
| |
| − | Number Source R.A. (1950) Decl. (1950) (arcmin) (arcmin) (arcmin) (deg) EYSO DC Class (pc) References
| |
| − | (1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13)
| |
| − | 1 . . . . . . . . L1275 00 00 48.2 67 02 05 8.2 1.5 3.5 25 N 4 5 . . . . . .
| |
| − | 2 . . . . . . . . L1291 00 39 47.6 61 44 35 1.5 1.5 1.5 0 N 2 5 . . . . . .
| |
| − | 3 . . . . . . . . L1333 02 21 10.2 75 13 32 2.8 1.7 2.2 2 N 3 6 . . . . . .
| |
| − | 4 . . . . . . . . L1355 02 48 41.4 68 43 36 3.5 1.6 2.4 8 N 3 6 300 1
| |
| − | 5 . . . . . . . . L1358-1 02 51 13.3 69 01 38 1.9 1.4 1.6 14 Y 2 6 . . . . . .
| |
| − | 6 . . . . . . . . L1358-2 02 51 55.1 69 12 03 2.8 1.3 1.9 [87 N 2 6 . . . . . .
| |
| − | 7 . . . . . . . . B5-1 03 44 26.4 32 46 45 3.2 1.6 2.3 [43 N 1 . . . 350 2
| |
| − | 8 . . . . . . . . B5-2 03 45 15.5 32 45 07 2.1 1.8 1.9 24 N 1 . . . 350 2
| |
| − | 9 . . . . . . . . CB 17 (L1389) 04 00 35.4 56 47 50 1.7 0.6 1.0 [44 Y 3 6 170 3
| |
| − | 10 . . . . . . L1498 04 07 51.8 25 01 35 3.2 1.6 2.3 [71 N 1 5 140 4
| |
| − | 11 . . . . . . L1495-2 04 14 51.2 28 30 40 6.3 5.1 5.7 7 N 3 5 140 4
| |
| − | 12 . . . . . . L1495-3 04 15 23.9 28 21 21 12.0 5.7 8.3 15 Y 3 5 140 4
| |
| − | 13 . . . . . . L1506B 04 16 03.9 25 13 01 7.9 2.2 4.2 [85 N 1 6 140 4
| |
| − | 14 . . . . . . L1399-1 04 20 00.5 55 01 00 . . . . . . 6.2 . . . N 1 5 170 3
| |
| − | 15 . . . . . . L1506A 04 20 30.1 24 58 29 20.2 9.5 13.9 [64 Y 2 6 140 4
| |
| − | 16 . . . . . . L1521B-2 04 20 32.8 26 33 11 . . . . . . 6.2 . . . N 2 4 140 4
| |
| − | 17 . . . . . . L1399-2 04 20 58.3 54 52 48 . . . . . . 9.2 . . . N 2 5 170 3
| |
| − | 18 . . . . . . L1521B-1 04 21 11.6 26 29 12 4.7 4.7 4.7 0 N 2 4 140 4
| |
| − | 19 . . . . . . L1399-3 04 21 11.8 54 49 59 . . . . . . 9.2 . . . N 2 5 170 3
| |
| − | 20 . . . . . . B213-7 04 22 12.8 26 26 10 . . . . . . 5.4 . . . N 1 . . . 140 4
| |
| − | 21 . . . . . . B217-1 04 24 44.5 26 11 27 3.2 1.7 2.3 [21 Y 1 . . . 140 4
| |
| − | 22 . . . . . . B217-2 04 25 04.5 26 14 16 3.3 1.9 2.5 38 N 2 . . . 140 4
| |
| − | 23 . . . . . . L1400A-2 04 25 05.8 54 39 40 4.1 1.3 2.3 [81 N 3 3 170 3
| |
| − | 24 . . . . . . L1521-1 (L1521F) 04 25 29.0 26 45 04 6.9 4.4 5.5 [55 N 1 4 140 4
| |
| − | 25 . . . . . . L1400F (L1407) 04 25 37.0 54 07 23 15.2 10.1 12.4 65 N 2 3 170 3
| |
| − | 26 . . . . . . L1524-2 04 26 16.9 24 25 02 6.3 5.2 5.7 [86 Y 2 5 140 4
| |
| − | 27 . . . . . . L1521E 04 26 17.2 26 07 34 2.7 1.7 2.1 90 N 1 4 140 4
| |
| − | 28 . . . . . . L1524-1 04 26 17.8 24 31 26 6.5 3.6 4.8 [71 Y 2 5 140 4
| |
| − | 29 . . . . . . L1521-2 04 26 26.8 26 53 27 5.5 2.5 3.7 [69 N 1 4 140 4
| |
| − | 30 . . . . . . L1400K 04 26 41.6 54 44 16 . . . . . . 5.2 . . . N 4 3 170 3
| |
| − | 31 . . . . . . L1524-3 04 26 51.5 24 23 44 10.8 5.4 7.6 [36 Y 2 5 140 4
| |
| − | 32 . . . . . . L1524-4 04 27 04.1 24 18 47 10.8 5.4 7.6 [36 N 2 5 140 4
| |
| − | 33 . . . . . . L1551S-2 04 28 03.5 18 09 09 5.7 3.8 4.7 [11 N 1 6 140 4
| |
| − | 34 . . . . . . L1445 04 28 28.8 46 31 01 8.2 2.2 4.2 [10 N 2 5 . . . . . .
| |
| − | 35 . . . . . . TMC 2-2 (L1529) 04 28 35.8 24 17 29 4.6 2.1 3.1 63 Y 1 5 140 4
| |
| − | 36 . . . . . . L1551S-1 04 28 53.9 18 01 14 2.8 1.3 1.9 [41 N 1 6 140 4
| |
| − | 37 . . . . . . TMC 2A (L1529) 04 28 59.1 24 25 42 9.5 4.7 6.7 [40 Y 1 5 140 4
| |
| − | 38 . . . . . . B18-2 04 29 34.4 24 45 46 3.8 1.7 2.5 [55 N 2 . . . 140 4
| |
| − | 39 . . . . . . TMC 2-1 (L1529) 04 29 37.5 24 18 14 . . . . . . 7.0 . . . Y 1 5 140 4
| |
| − | 40 . . . . . . L1536-2 04 29 50.7 22 53 29 2.7 2.0 2.3 [2 N 1 4 140 4
| |
| − | 41 . . . . . . TMC 2-3 (L1529) 04 29 57.6 24 11 26 4.3 2.5 3.3 [70 N 1 5 140 4
| |
| − | 42 . . . . . . L1536-3 04 30 01.7 22 47 41 2.4 0.9 1.5 76 N 1 4 140 4
| |
| − | 43 . . . . . . L1536-1 04 30 19.7 22 36 51 11.4 5.1 7.6 [88 N 1 4 140 4
| |
| − | 44 . . . . . . B18-3 04 31 04.6 24 03 32 7.9 1.9 3.9 [55 N 3 . . . 140 4
| |
| − | 45 . . . . . . B18-4 04 32 34.0 24 02 48 4.1 3.8 3.9 2 Y 3 . . . 140 4
| |
| − | 46 . . . . . . B18-5 04 32 49.7 24 03 15 3.0 2.1 2.5 [37 N 2 . . . 140 4
| |
| − | 47 . . . . . . L1527A-1 04 35 05.1 26 08 37 7.6 4.4 5.8 [75 Y 1 6 140 4
| |
| − | 48 . . . . . . L1527A-2 04 35 54.0 26 15 38 4.0 1.5 2.4 5 N 1 6 140 4
| |
| − | 49 . . . . . . L1534 04 36 36.4 25 35 14 9.5 6.3 7.7 [73 Y 1 5 140 4
| |
| − | 50 . . . . . . CB 22 (L1503) 04 37 30.2 29 47 13 4.7 1.7 2.8 [43 N 2 5 140 4
| |
| − | 51 . . . . . . TMC 1-1 (L1527) 04 38 26.5 25 39 27 15.8 4.7 8.6 [40 Y 2 6 140 4
| |
| − | 52 . . . . . . TMC 1C (L1527) 04 38 27.5 25 55 46 12.6 5.7 8.5 [52 Y 2 6 140 4
| |
| − | 53 . . . . . . L1507-1 04 39 29.4 29 36 24 4.7 2.2 3.2 [13 N 2 5 140 4
| |
| − | 54 . . . . . . L1507-2 04 39 53.4 29 38 25 3.5 1.6 2.4 71 N 1 5 140 4
| |
| − | 55 . . . . . . L1507-3 04 40 21.4 29 33 37 1.7 0.9 1.2 38 N 2 5 140 4
| |
| − | 56 . . . . . . L1426 04 43 17.5 52 59 03 2.1 2.1 2.1 0 N 1 5 170 3
| |
| − | 57 . . . . . . L1517C 04 51 33.6 30 30 54 4.7 3.2 3.9 [69 N 2 6 140 4
| |
| − | 58 . . . . . . L1517B-2 04 51 56.4 30 38 03 3.2 2.1 2.6 [45 N 1 6 140 4
| |
| − | 59 . . . . . . L1517A 04 51 56.7 30 29 20 4.7 2.5 3.4 [64 N 2 6 140 4
| |
| − | 60 . . . . . . L1517B-1 04 52 05.9 30 32 58 4.7 1.7 2.8 [4 N 3 6 140 4
| |
| − | 61 . . . . . . L1517D 04 52 45.7 30 35 14 4.7 2.4 3.4 [45 N 2 6 140 4
| |
| − | 62 . . . . . . L1544-3 05 00 38.6 25 14 18 4.7 2.4 3.4 90 N 1 6 140 4
| |
| − | 63 . . . . . . L1512 (CB 27) 05 00 54.4 32 39 00 4.7 2.2 3.2 [13 N 3 6 140 4
| |
| − | 64 . . . . . . L1544-1 05 01 18.3 25 07 29 . . . . . . 5.8 . . . N 1 6 140 4
| |
| − | 65 . . . . . . L1544-2 05 01 39.1 25 07 30 2.4 1.9 2.1 [60 N 1 6 140 4
| |
| − | 238
| |
| − | TABLE 2ÈContinued
| |
| − | a b R PA Distance
| |
| − | Number Source R.A. (1950) Decl. (1950) (arcmin) (arcmin) (arcmin) (deg) EYSO DC Class (pc) References
| |
| − | (1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13)
| |
| − | 66 . . . . . . . L1523 05 03 02.7 31 37 30 5.1 1.9 3.1 12 N 2 6 140 4
| |
| − | 67 . . . . . . . CB 28 05 03 51.2 [04 00 20 3.6 2.4 2.9 83 N 2 . . . 500 5
| |
| − | 68 . . . . . . . L1552 05 14 34.9 26 01 17 5.9 2.5 3.8 [1 N 3 6 140 4
| |
| − | 69 . . . . . . . L1582A 05 29 15.0 12 28 57 5.2 2.4 3.5 [52 N 4 5 400 6
| |
| − | 70 . . . . . . . B35A 05 41 50.5 09 09 17 3.2 1.6 2.3 11 Y 2 . . . 400 7
| |
| − | 71 . . . . . . . L1622A 05 52 17.1 01 56 55 5.1 1.1 2.4 39 N 3 6 500 5
| |
| − | 72 . . . . . . . L1622B 05 52 17.5 01 45 11 2.2 1.1 1.6 87 Y 3 6 500 5
| |
| − | 73 . . . . . . . L1621-2 05 52 49.8 02 08 07 1.0 0.8 0.9 90 N 2 4 500 5
| |
| − | 74 . . . . . . . L1621-1 05 53 23.0 02 17 39 5.9 1.1 2.5 25 N 3 4 500 5
| |
| − | 75 . . . . . . . CB 37 (L1555) 05 57 29.9 31 39 25 4.7 3.1 3.8 [87 N 3 4 . . . . . .
| |
| − | 76 . . . . . . . L1574 06 05 08.9 18 28 41 2.5 0.9 1.5 [11 N 1 4 . . . . . .
| |
| − | 77 . . . . . . . L1645 06 05 16.2 [05 32 16 4.9 1.3 2.5 6 Y 1 4 830 9
| |
| − | 78 . . . . . . . L1578-2 06 05 40.4 18 12 00 13.3 5.7 8.7 7 PM* 3 4 . . . . . .
| |
| − | 79 . . . . . . . L1578-1 06 05 41.6 18 06 54 13.3 5.7 8.7 7 PM* 2 4 . . . . . .
| |
| − | 80 . . . . . . . CB 45 (L1578) 06 06 02.0 17 50 48 2.4 1.6 2.0 [38 N 3 4 . . . . . .
| |
| − | 81 . . . . . . . L1633 06 22 04.0 03 23 53 1.4 1.4 1.4 0 N 3 4 . . . . . .
| |
| − | 82 . . . . . . . DC 2592[132-1 (V4) 07 29 02.8 [46 37 10 1.6 0.5 0.9 88 N 4 A 300 10
| |
| − | 83 . . . . . . . DC 2592[132-2 (V4) 07 29 20.3 [46 49 26 2.2 1.6 1.9 [31 N 3 A 300 10
| |
| − | 84 . . . . . . . DC 2555[48 08 03 46.1 [39 00 10 5.2 0.9 2.2 86 N 3 A 300 10
| |
| − | 85 . . . . . . . V13-2 08 06 54.9 [35 54 21 2.5 1.4 1.9 [54 N 4 A 300 10
| |
| − | 86 . . . . . . . V13-3 08 07 01.0 [35 48 22 3.2 0.7 1.5 [28 N 4 A 300 10
| |
| − | 87 . . . . . . . V13-1 08 07 09.0 [35 52 18 0.8 0.6 0.7 7 N 4 A 300 10
| |
| − | 88 . . . . . . . V14 08 07 39.9 [35 56 04 . . . . . . 1.8 . . . Y 4 A 300 10
| |
| − | 89 . . . . . . . DC 2573[25-1 08 15 19.5 [39 44 40 2.5 1.6 2.0 43 Y 4 A 300 10
| |
| − | 90 . . . . . . . DC 2573[25-2 08 15 23.8 [39 41 40 1.3 0.9 1.1 39 N 3 A 300 10
| |
| − | 91 . . . . . . . DC 2660[75-2 08 19 40.0 [49 31 38 . . . . . . 5.0 . . . Y 3 A 300 10
| |
| − | 92 . . . . . . . DC 2660[75-1 08 19 53.7 [49 41 10 . . . . . . 7.0 . . . N 3 A 300 10
| |
| − | 93 . . . . . . . DC 2674[75 08 24 15.2 [50 52 08 5.6 2.4 3.7 32 Y 4 A 300 10
| |
| − | 94 . . . . . . . DC 2672[72 08 25 03.5 [50 30 11 . . . . . . 2.0 . . . Y 4 A 300 10
| |
| − | 95 . . . . . . . DC 2675[74 08 25 10.2 [50 52 00 1.9 1.1 1.4 4 N 4 A 300 10
| |
| − | 96 . . . . . . . DC 2676[60-1 08 32 36.6 [50 08 03 1.9 1.1 1.4 [73 N 4 A 300 10
| |
| − | 97 . . . . . . . DC 2676[60-2 08 32 45.3 [50 14 33 1.4 0.8 1.1 32 N 4 A 300 10
| |
| − | 98 . . . . . . . DC 2694]30 (V27) 09 20 28.7 [45 35 05 8.1 1.6 3.6 [34 N 4 A 300 10
| |
| − | 99 . . . . . . . DC 2695]40 09 24 18.1 [44 58 32 6.3 0.9 2.4 72 N 3 A 300 10
| |
| − | 100 . . . . . . DC 2742[04 09 27 05.5 [51 23 14 4.6 1.9 3.0 12 N 4 A 300 10
| |
| − | 101 . . . . . . DC 2962[158 10 49 28.9 [76 48 59 . . . . . . 4.6 . . . N 3 A 150 11
| |
| − | 102 . . . . . . DC 2965[157 10 55 31.7 [76 48 52 4.7 1.9 3.0 [2 N 2 A 150 11
| |
| − | 103 . . . . . . DC 29103[35 10 57 12.9 [63 26 49 10.7 2.5 5.2 [76 N 1 A . . . . . .
| |
| − | 104 . . . . . . DC 2971[161-1 11 01 09.3 [77 26 22 9.5 3.2 5.5 34 N 3 A 150 11
| |
| − | 105 . . . . . . DC 2971[161-2 11 01 39.8 [77 32 55 . . . . . . 5.8 . . . N 3 A 150 11
| |
| − | 106 . . . . . . DC 2972[151 11 09 47.9 [76 38 29 10.1 4.7 6.9 [48 N 2 A 150 11
| |
| − | 107 . . . . . . DC 2983[131 11 37 59.1 [75 00 00 3.5 2.7 3.1 [56 N 3 A 150 11
| |
| − | 108 . . . . . . DC 2977[28 11 59 07.2 [64 52 15 6.9 3.2 4.7 [47 Y 1 A 175 12
| |
| − | 109 . . . . . . Mu 4 12 21 29.0 [71 35 56 3.9 0.8 1.8 25 N 1 A 225 13
| |
| − | 110 . . . . . . DC 3002[35 12 21 30.2 [65 55 26 7.3 1.3 3.1 [78 N 1 A 175 12
| |
| − | 111 . . . . . . Mu 8 12 26 39.0 [70 54 04 8.4 1.0 2.9 39 N 1 A 225 13
| |
| − | 112 . . . . . . Mu 10 12 28 03.4 [70 46 30 . . . . . . 8.4 . . . N 1 A 225 13
| |
| − | 113 . . . . . . DC 3020[177-1 12 28 22.6 [80 19 54 2.8 1.3 1.9 [40 N 3 A 200 14
| |
| − | 114 . . . . . . DC 3007[10 (Co2) 12 28 50.6 [63 28 02 10.1 6.6 8.2 [32 N 1 A 175 12
| |
| − | 115 . . . . . . DC 3023[177 12 31 54.0 [80 13 31 3.3 1.6 2.3 26 N 3 A 200 14
| |
| − | 116 . . . . . . DC 3020[177-2 12 33 06.8 [80 20 35 1.9 1.3 1.6 48 N 3 A 200 14
| |
| − | 117 . . . . . . DC 3025[175 12 37 03.2 [80 03 39 3.0 0.6 1.3 52 N 3 A 200 14
| |
| − | 118 . . . . . . DC 3026[159 12 41 21.4 [78 31 56 2.1 1.3 1.7 [51 N 3 A 200 14
| |
| − | 119 . . . . . . Ch 5 12 46 38.7 [76 41 04 9.3 3.5 5.7 65 N 2 A 200 14
| |
| − | 120 . . . . . . DC 3030[143 (Ch 7) 12 49 14.6 [76 56 33 8.5 6.0 7.1 [59 Y 1 A 200 14
| |
| − | 121 . . . . . . Ch 17 12 54 44.8 [76 56 34 5.7 3.2 4.3 [32 N 2 A 200 14
| |
| − | 122 . . . . . . Ch 19-2 12 56 59.5 [77 02 36 9.5 3.8 6.0 [24 N 2 A 200 14
| |
| − | 123 . . . . . . Ch 19-1 12 57 24.1 [76 57 01 9.5 3.8 6.0 [24 Y 2 A 200 14
| |
| − | 124 . . . . . . Ch 20 12 59 18.9 [77 06 56 2.8 1.7 2.2 [32 N 2 A 200 14
| |
| − | 125 . . . . . . DC 3037[145 13 01 12.6 [77 09 35 4.6 2.8 3.6 17 N 2 A 200 14
| |
| − | 126 . . . . . . DC 3037[148 13 01 39.7 [77 26 49 3.2 1.6 2.3 [22 N 1 A 200 14
| |
| − | 127 . . . . . . DC 3037[152 13 01 51.6 [77 45 01 . . . . . . 5.0 . . . N 2 A 200 14
| |
| − | 128 . . . . . . DC 3037[150 13 02 00.5 [77 37 08 4.7 3.7 4.2 0 N 2 A 200 14
| |
| − | 129 . . . . . . DC 3038[142 13 03 36.4 [76 44 48 4.7 2.4 3.4 78 Y 2 A 200 14
| |
| − | 130 . . . . . . DC 3162]51 14 22 33.6 [55 07 04 . . . . . . 4.8 . . . N 4 A . . . . . .
| |
| − | 131 . . . . . . DC 3148[51 14 44 23.4 [65 04 41 10.1 2.2 4.7 [82 Y 1 A 170 15
| |
| − | 239
| |
| − | TABLE 2ÈContinued
| |
| − | a b R PA Distance
| |
| − | Number Source R.A. (1950) Decl. (1950) (arcmin) (arcmin) (arcmin) (deg) EYSO DC Class (pc) References
| |
| − | (1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13)
| |
| − | 132 . . . . . . DC 3230]40 15 07 35.6 [53 06 36 2.4 1.1 1.6 55 N 3 A . . . . . .
| |
| − | 133 . . . . . . DC 3379]164 15 36 25.2 [34 36 48 3.8 2.8 3.3 [18 Y 3 A 170 16
| |
| − | 134 . . . . . . DC 3382]164 15 37 23.9 [34 30 40 4.7 2.1 3.1 4 N 4 A 170 16
| |
| − | 135 . . . . . . DC 3272]18 15 38 33.4 [52 38 36 . . . . . . 3.0 . . . N 4 A . . . . . .
| |
| − | 136 . . . . . . DC 3388]165-2 15 39 08.8 [33 41 27 4.1 3.2 3.6 [67 N 3 A 170 16
| |
| − | 137 . . . . . . DC 3388]165-3 15 39 29.2 [33 42 30 5.7 2.5 3.8 [50 N 3 A 170 16
| |
| − | 138 . . . . . . DC 3388]165-4 15 39 32.4 [33 59 44 . . . . . . 8.8 . . . Y 3 A 170 16
| |
| − | 139 . . . . . . DC 3388]165-5 15 39 49.9 [33 59 18 . . . . . . 8.8 . . . Y 3 A 170 16
| |
| − | 140 . . . . . . DC 3388]165-6 15 40 06.5 [34 04 01 2.5 1.9 2.2 [86 N 2 A 170 16
| |
| − | 141 . . . . . . DC 3392]161-1 15 41 42.7 [34 08 10 10.1 5.7 7.6 40 Y 3 A 170 16
| |
| − | 142 . . . . . . DC 3392]161-2 15 42 01.1 [34 03 59 4.1 2.5 3.2 52 N 3 A 170 16
| |
| − | 143 . . . . . . DC 3392]161-3 15 42 03.2 [34 11 21 2.4 1.4 1.8 [72 N 3 A 170 16
| |
| − | 144 . . . . . . DC 3392]161-4 15 42 16.9 [34 15 19 6.5 3.6 4.8 19 N 3 A 170 16
| |
| − | 145 . . . . . . DC 3389]151 15 43 24.3 [35 02 46 7.9 1.4 3.3 [47 N 3 A 170 16
| |
| − | 146 . . . . . . DC 3390]150 15 44 46.3 [35 03 29 5.1 2.2 3.3 [7 Y 4 A 170 16
| |
| − | 147 . . . . . . L134A 15 50 49.0 [04 25 00 4.9 4.9 4.9 0 N 1 5 165 17
| |
| − | 148 . . . . . . L183 15 51 22.8 [02 40 44 6.3 3.8 4.9 51 N 2 5 165 17
| |
| − | 149 . . . . . . DC 3386]119-1 15 53 25.0 [37 45 27 6.5 2.4 3.9 21 N 3 A 170 16
| |
| − | 150 . . . . . . DC 3386]119-2 15 53 40.4 [37 39 54 5.1 3.2 4.0 64 Y 4 A 170 16
| |
| − | 151 . . . . . . DC 3356]82 15 54 42.3 [42 26 57 7.1 1.7 3.5 [88 N 3 A 170 16
| |
| − | 152 . . . . . . DC 3391]117-1 15 55 22.3 [37 30 42 2.5 1.6 2.0 71 N 4 A 170 16
| |
| − | 153 . . . . . . DC 3391]117-2 15 55 45.6 [37 28 26 4.1 2.4 3.1 33 N 4 A 170 16
| |
| − | 154 . . . . . . DC 3364]82 15 57 26.9 [41 55 44 17.7 11.1 14.0 90 N 4 A 170 16
| |
| − | 155 . . . . . . DC 3367]82 15 58 00.8 [41 44 44 15.8 3.8 7.7 57 N 4 A 170 16
| |
| − | 156 . . . . . . DC 3369]83 15 59 05.3 [41 31 30 6.3 2.8 4.2 [31 N 4 A 170 16
| |
| − | 157 . . . . . . DC 3386]95 16 01 09.6 [39 29 37 . . . . . . 4.0 . . . N 4 A 170 16
| |
| − | 158 . . . . . . DC 3346]46 16 02 54.2 [45 46 25 6.9 3.8 5.1 44 N 2 A 170 16
| |
| − | 159 . . . . . . DC 3394]95 16 04 27.0 [39 04 06 4.3 2.4 3.2 [29 N 3 A 170 16
| |
| − | 160 . . . . . . DC 3376]76 16 04 58.6 [41 32 54 8.2 3.8 5.6 22 N 4 A 170 16
| |
| − | 161 . . . . . . DC 3397]92-1 16 06 19.9 [39 01 37 . . . . . . 11.8 . . . Y 3 A 170 16
| |
| − | 162 . . . . . . DC 3397]92-2 16 06 45.1 [38 55 58 . . . . . . 11.8 . . . Y 3 A 170 16
| |
| − | 163 . . . . . . DC 3397]92-3 16 07 01.5 [39 03 00 . . . . . . 11.8 . . . Y 3 A 170 16
| |
| − | 164 . . . . . . DC 3381]71 16 07 59.4 [41 34 19 14.5 8.2 10.9 80 N 3 A 170 16
| |
| − | 165 . . . . . . DC 3402]90-1 16 08 01.0 [38 53 49 . . . . . . 8.2 . . . PM 3 A 170 16
| |
| − | 166 . . . . . . DC 3402]90-2 16 08 15.2 [38 50 38 . . . . . . 8.2 . . . PM 3 A 170 16
| |
| − | 167 . . . . . . DC 3402]90-3 16 08 23.4 [38 53 56 . . . . . . 8.2 . . . PM 3 A 170 16
| |
| − | 168 . . . . . . DC 3369]51 16 10 18.3 [43 53 34 11.4 3.2 6.0 [60 N 3 A 170 16
| |
| − | 169 . . . . . . DC 3420]94 16 14 28.7 [37 23 52 4.4 3.3 3.8 [11 N 3 A 170 16
| |
| − | 170 . . . . . . DC 3412]65 16 21 44.4 [39 52 38 11.4 3.2 6.0 [52 N 1 A 170 16
| |
| − | 171 . . . . . . L1681A 16 23 58.5 [24 27 39 . . . . . . 26.6 . . . Y 4 5 165 17
| |
| − | 172 . . . . . . L1696B-1 16 24 40.3 [24 06 24 . . . . . . 11.0 . . . Y 4 6 165 17
| |
| − | 173 . . . . . . L1696A 16 25 27.5 [24 12 48 . . . . . . 11.0 . . . N 4 6 165 17
| |
| − | 174 . . . . . . L1696B-2 16 26 09.4 [24 06 43 6.6 3.8 5.0 [35 N 4 6 165 17
| |
| − | 175 . . . . . . L1704-1 16 27 49.8 [23 35 49 4.9 3.2 4.0 32 N 4 6 165 17
| |
| − | 176 . . . . . . L1704-2 16 28 09.3 [23 34 29 3.3 1.7 2.4 [17 N 4 6 165 17
| |
| − | 177 . . . . . . L1709B-1 16 28 35.4 [23 52 19 44.2 7.6 18.3 54 Y 4 6 165 17
| |
| − | 178 . . . . . . L1757-1 16 29 01.9 [19 35 24 . . . . . . 11.0 . . . N 3 6 165 17
| |
| − | 179 . . . . . . L1757-2 16 29 08.5 [19 42 05 . . . . . . 11.0 . . . N 3 6 165 17
| |
| − | 180 . . . . . . L1689A 16 29 10.4 [24 56 03 2.8 1.6 2.1 11 N 2 6 165 17
| |
| − | 181 . . . . . . L1689B2 16 29 11.4 [24 18 43 9.8 3.6 5.9 [14 Y 3 6 165 17
| |
| − | 182 . . . . . . L1709B-2 16 29 49.3 [23 46 22 44.2 7.6 18.3 54 N 4 6 165 17
| |
| − | 183 . . . . . . L1709C-2 16 30 18.0 [23 40 01 44.2 7.6 18.3 54 N 4 6 165 17
| |
| − | 184 . . . . . . L1689B3 16 30 26.5 [24 37 33 9.5 4.7 6.7 81 N 4 6 165 17
| |
| − | 185 . . . . . . L1689B4 16 30 27.0 [24 21 55 7.6 4.4 5.8 [64 Y 4 6 165 17
| |
| − | 186 . . . . . . DC 3387]18 16 30 33.3 [44 54 53 9.5 1.4 3.6 [66 Y 3 A 700 32
| |
| − | 187 . . . . . . L1709C-1 16 30 52.6 [23 33 54 44.2 7.6 18.3 54 N 4 6 165 17
| |
| − | 188 . . . . . . L1689B5 16 30 55.8 [24 28 16 . . . . . . 17.4 . . . Y 3 6 165 17
| |
| − | 189 . . . . . . L43F 16 31 03.9 [15 45 31 21.8 1.9 6.4 64 N 3 6 165 17
| |
| − | 190 . . . . . . L43D 16 31 28.8 [15 42 54 21.8 1.9 6.4 64 Y 3 6 165 17
| |
| − | 191 . . . . . . L1689B1 16 31 35.2 [24 29 47 . . . . . . 17.4 . . . Y 4 6 165 17
| |
| − | 192 . . . . . . L43E 16 31 47.7 [15 40 51 21.8 1.9 6.4 64 Y 3 6 165 17
| |
| − | 193 . . . . . . DC 3460]78 16 33 34.7 [35 30 27 4.1 2.1 2.9 5 N 4 A 170 16
| |
| − | 194 . . . . . . DC 3464]79 16 34 13.4 [35 08 26 3.8 2.4 3.0 [51 N 4 A 170 16
| |
| − | 195 . . . . . . DC 3463]78 16 34 26.8 [35 21 54 5.9 1.7 3.2 32 N 4 A 170 16
| |
| − | 196 . . . . . . L121 16 36 41.0 [13 59 21 3.1 1.7 2.3 8 N 1 5 165 17
| |
| − | 197 . . . . . . L1782-1 16 39 13.2 [19 36 22 6.0 1.7 3.2 [40 N 1 6 165 17
| |
| − | 240
| |
| − | TABLE 2ÈContinued
| |
| − | a b R PA Distance
| |
| − | Number Source R.A. (1950) Decl. (1950) (arcmin) (arcmin) (arcmin) (deg) EYSO DC Class (pc) References
| |
| − | (1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13)
| |
| − | 198 . . . . . . L1782-2 16 39 36.4 [19 38 00 3.8 2.7 3.2 35 N 2 6 165 17
| |
| − | 199 . . . . . . DC 3393-03 16 42 30.0 [45 54 54 4.3 1.4 2.5 [87 N 4 A 700 32
| |
| − | 200 . . . . . . DC 3405]05 16 43 05.8 [44 26 04 7.1 2.5 4.2 62 N 4 A 700 32
| |
| − | 201 . . . . . . L158-2 16 44 02.6 [13 53 26 8.2 4.1 5.8 55 N 2 6 165 17
| |
| − | 202 . . . . . . L204C-1 16 44 30.6 [12 14 14 5.7 2.2 3.5 1 N 3 6 165 17
| |
| − | 203 . . . . . . L260 16 44 32.5 [09 29 58 7.6 4.1 5.6 [73 Y 2 6 165 17
| |
| − | 204 . . . . . . L204C-2 16 44 58.5 [12 18 04 3.6 1.6 2.4 [5 N 3 6 165 17
| |
| − | 205 . . . . . . L191-1 16 44 59.6 [12 34 43 6.0 2.5 3.9 [52 N 2 5 165 17
| |
| − | 206 . . . . . . L191-2 16 45 01.7 [12 47 38 1.7 1.4 1.5 58 N 1 5 165 17
| |
| − | 207 . . . . . . L255-1 16 45 01.9 [09 48 32 6.3 4.0 5.0 54 Y 3 6 165 17
| |
| − | 208 . . . . . . L234E1 16 45 22.6 [10 52 10 11.7 0.9 3.2 2 N 3 3 165 17
| |
| − | 209 . . . . . . L234E2 16 45 23.2 [10 46 37 11.7 0.9 3.2 2 Y 2 3 165 17
| |
| − | 210 . . . . . . L255-2 16 45 30.9 [09 58 47 4.9 1.9 3.1 [5 N 2 6 165 17
| |
| − | 211 . . . . . . L158-3 16 45 33.9 [14 03 18 7.9 4.1 5.7 54 Y 3 6 165 17
| |
| − | 212 . . . . . . L234E3 16 45 49.0 [10 45 45 3.3 2.1 2.6 56 N 2 3 165 17
| |
| − | 213 . . . . . . L158-4 16 46 22.0 [14 05 23 7.0 3.5 4.9 81 Y 2 6 165 17
| |
| − | 214 . . . . . . L162-1 16 46 22.3 [14 05 33 . . . . . . 7.6 . . . Y 1 6 165 17
| |
| − | 215 . . . . . . L63-4 16 46 49.1 [17 49 47 3.2 1.6 2.3 [49 N 1 6 165 17
| |
| − | 216 . . . . . . L63-3 16 47 10.5 [17 53 51 5.2 1.4 2.7 [25 N 1 6 165 17
| |
| − | 217 . . . . . . L63-2 16 47 11.2 [17 59 52 5.9 3.6 4.6 [82 N 1 6 165 17
| |
| − | 218 . . . . . . L63-1 16 47 20.5 [18 00 53 5.9 3.6 4.6 [82 N 1 6 165 17
| |
| − | 219 . . . . . . L141-2 16 48 03.1 [15 16 54 . . . . . . 6.8 . . . N 2 5 165 17
| |
| − | 220 . . . . . . L141-3 16 48 11.1 [15 12 04 6.9 1.9 3.6 54 N 2 5 165 17
| |
| − | 221 . . . . . . L129-2 16 51 57.6 [16 21 42 2.5 1.1 1.7 25 N 1 6 165 17
| |
| − | 222 . . . . . . L129-1 16 52 18.4 [16 17 10 3.5 1.6 2.4 [79 N 1 6 165 17
| |
| − | 223 . . . . . . L122 16 52 22.4 [16 42 03 3.0 2.1 2.5 80 N 2 6 165 17
| |
| − | 224 . . . . . . CB 68-3 (L146) 16 53 05.4 [15 52 21 11.4 7.9 9.5 [25 Y 2 5 165 17
| |
| − | 225 . . . . . . CB 68-2 (L146) 16 54 00.0 [15 57 11 2.8 1.3 1.9 [5 N 1 5 165 17
| |
| − | 226 . . . . . . CB 68-1 (L146) 16 54 27.5 [16 04 09 4.1 2.1 2.9 [40 Y 2 5 165 17
| |
| − | 227 . . . . . . DC 3504]44 16 59 40.9 [34 20 44 8.8 6.9 7.8 0 N 1 A 170 16
| |
| − | 228 . . . . . . L111 17 11 59.5 [20 27 15 4.3 1.4 2.5 66 N 1 6 165 17
| |
| − | 229 . . . . . . L100 17 13 07.6 [20 54 04 12.3 4.7 7.6 [21 Y/PM 1 6 165 17
| |
| − | 230 . . . . . . L173 17 14 25.4 [18 27 45 9.5 3.2 5.5 [11 N 1 6 165 17
| |
| − | 231 . . . . . . L1772 17 16 25.8 [26 41 37 9.3 3.6 5.8 53 N 1 6 165 17
| |
| − | 232 . . . . . . L1768 17 16 35.0 [26 52 57 13.0 1.6 4.6 81 N 1 6 165 17
| |
| − | 233 . . . . . . L1773 17 18 08.4 [26 50 46 12.0 4.4 7.3 [45 N 1 6 165 17
| |
| − | 234 . . . . . . L1774 17 19 32.1 [27 02 25 7.9 3.2 5.0 [82 Y 1 6 165 17
| |
| − | 235 . . . . . . B68-1 17 19 36.0 [23 47 13 3.8 2.4 3.0 [48 N 2 . . . 165 17
| |
| − | 236 . . . . . . B68-2 17 20 34.0 [23 37 32 4.3 3.5 3.9 [26 N 2 . . . 165 17
| |
| − | 237 . . . . . . B68-3 17 20 49.4 [23 39 57 8.2 2.5 4.5 45 N 2 . . . 165 17
| |
| − | 238 . . . . . . DC 3463[41 17 22 40.3 [42 37 01 12.6 4.4 7.4 62 PM 1 A . . . . . .
| |
| − | 239 . . . . . . DC 3479[44 17 28 52.7 [41 32 37 . . . . . . 3.6 . . . N 2 A . . . . . .
| |
| − | 240 . . . . . . L425 17 44 15.4 [04 34 07 . . . . . . 6.6 . . . Y 1 5 . . . . . .
| |
| − | 241 . . . . . . DC 3475[80 17 44 26.1 [43 42 02 5.2 2.5 3.6 [81 N 1 A . . . . . .
| |
| − | 242 . . . . . . L392 17 50 24.3 [08 26 43 6.5 2.7 4.2 33 N 1 5 200 18
| |
| − | 243 . . . . . . L421 17 51 38.9 [05 46 02 1.6 1.6 1.6 0 N 1 5 200 18
| |
| − | 244 . . . . . . L460 17 55 24.4 [03 46 24 7.6 3.2 4.9 [52 N 1 6 200 18
| |
| − | 245 . . . . . . L432 17 55 46.2 [05 43 45 10.1 3.2 5.7 [8 N 1 6 200 18
| |
| − | 246 . . . . . . L468 17 57 38.0 [03 30 03 4.7 2.1 3.1 0 N 1 5 200 18
| |
| − | 247 . . . . . . L462-1 18 04 51.9 [04 43 57 4.9 2.1 3.2 90 N 1 6 200 18
| |
| − | 248 . . . . . . L462-2 18 04 56.9 [04 40 57 4.9 3.2 4.0 81 N 1 6 200 18
| |
| − | 249 . . . . . . L108 18 07 08.0 [28 18 41 2.8 1.4 2.0 [11 N 3 6 . . . . . .
| |
| − | 250 . . . . . . L422 18 09 20.0 [08 04 46 4.2 1.6 2.6 [36 N 2 6 . . . . . .
| |
| − | 251 . . . . . . L438 18 11 23.8 [07 10 01 3.2 1.7 2.3 [49 N 1 6 . . . . . .
| |
| − | 252 . . . . . . L436 18 11 53.0 [07 23 49 4.6 2.2 3.2 85 N 1 6 . . . . . .
| |
| − | 253 . . . . . . L323 (CB 125) 18 12 39.1 [18 11 47 . . . . . . 10.4 . . . Y 2 6 200 8
| |
| − | 254 . . . . . . L490 18 12 42.5 [03 47 11 3.3 2.2 2.7 [48 N 1 6 200 18
| |
| − | 255 . . . . . . L492 18 13 11.6 [03 47 17 3.8 2.7 3.2 [18 N 1 6 200 18
| |
| − | 256 . . . . . . CB 130-2 (L507) 18 13 37.5 [02 24 28 2.2 1.4 1.8 16 N 3 5 200 18
| |
| − | 257 . . . . . . CB 130-1 (L507) 18 13 39.2 [02 34 06 3.1 1.4 2.1 [88 N 3 5 200 18
| |
| − | 258 . . . . . . CB 130-3 (L507) 18 13 41.5 [02 17 47 3.0 1.3 2.0 61 N 3 5 200 18
| |
| − | 259 . . . . . . L328 18 14 05.3 [18 03 10 1.7 1.4 1.5 47 N 1 6 200 8
| |
| − | 260 . . . . . . L429-1 18 14 28.2 [08 14 40 21.5 8.8 13.8 42 N 2 6 200 18
| |
| − | 261 . . . . . . L429-2 18 14 32.8 [08 19 02 21.5 8.8 13.8 42 N 2 6 200 18
| |
| − | 262 . . . . . . L429-3 18 14 50.8 [08 15 17 21.5 8.8 13.8 42 N 2 6 200 18
| |
| − | 263 . . . . . . L483-1 18 14 54.8 [04 40 23 . . . . . . 11.4 . . . Y 1 6 200 18
| |
| − | 241
| |
| − | TABLE 2ÈContinued
| |
| − | a b R PA Distance
| |
| − | Number Source R.A. (1950) Decl. (1950) (arcmin) (arcmin) (arcmin) (deg) EYSO DC Class (pc) References
| |
| − | (1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13)
| |
| − | 264 . . . . . . L429-4 18 15 05.2 [08 10 07 21.5 8.8 13.8 42 N 2 6 200 18
| |
| − | 265 . . . . . . L483-2 18 15 26.5 [04 34 24 7.4 4.4 5.7 51 N 1 6 200 18
| |
| − | 266 . . . . . . L466 18 17 04.5 [06 07 36 6.3 5.1 5.7 45 N 1 6 200 18
| |
| − | 267 . . . . . . L451 18 19 12.3 [07 14 11 6.8 2.8 4.4 74 N 1 5 200 18
| |
| − | 268 . . . . . . L539-1 18 21 05.7 [01 04 28 . . . . . . 9.4 . . . N 1 6 200 18
| |
| − | 269 . . . . . . L539-2 18 21 46.5 [01 01 05 . . . . . . 5.2 . . . N 1 6 200 18
| |
| − | 270 . . . . . . L416 18 22 46.2 [10 41 26 . . . . . . 3.4 . . . N 3 6 200 18
| |
| − | 271 . . . . . . L406 18 22 50.5 [11 49 11 10.1 7.6 8.8 26 Y 3 5 200 18
| |
| − | 272 . . . . . . L423 18 25 03.9 [10 16 08 7.9 1.9 3.9 [82 N 1 5 200 18
| |
| − | 273 . . . . . . L411 18 25 07.9 [11 29 15 3.0 0.8 1.5 34 N 3 5 200 18
| |
| − | 274 . . . . . . L503 18 26 49.5 [04 40 45 . . . . . . 7.0 . . . N 2 6 200 18
| |
| − | 275 . . . . . . L443-1 18 29 47.1 [08 59 13 4.1 2.8 3.4 14 N 3 5 200 18
| |
| − | 276 . . . . . . L443-2 18 30 01.6 [09 14 41 5.2 4.6 4.9 [37 N 3 5 200 18
| |
| − | 277 . . . . . . L239 18 30 11.5 [26 04 16 3.0 2.4 2.7 [58 N 1 6 . . . . . .
| |
| − | 278 . . . . . . L443-3 18 30 12.0 [09 16 52 5.2 4.6 4.9 [37 N 2 5 200 18
| |
| − | 279 . . . . . . L588-2 18 32 47.0 [00 43 53 . . . . . . 3.8 . . . N 3 6 200 18
| |
| − | 280 . . . . . . L588-3 18 33 18.2 [00 33 25 2.4 1.3 1.8 61 N 3 6 200 18
| |
| − | 281 . . . . . . L588-4 18 33 39.2 [00 40 38 1.1 0.6 0.8 78 N 3 6 200 18
| |
| − | 282 . . . . . . L495 18 36 32.6 [06 41 06 4.9 2.4 3.4 86 N 1 6 200 18
| |
| − | 283 . . . . . . L648-1 18 37 09.7 12 38 37 . . . . . . 6.4 . . . N 4 6 . . . . . .
| |
| − | 284 . . . . . . L648-2 18 37 20.5 12 47 05 . . . . . . 6.4 . . . N 4 6 . . . . . .
| |
| − | 285 . . . . . . L530D-3 18 46 48.0 [05 03 12 6.6 4.0 5.1 11 N 1 6 350 19
| |
| − | 286 . . . . . . L530D-1 18 47 20.5 [04 51 55 16.1 6.9 10.5 5 N 1 6 350 19
| |
| − | 287 . . . . . . L530D-2 18 47 22.1 [04 43 25 16.1 6.9 10.5 5 N 1 6 350 19
| |
| − | 288 . . . . . . L549 18 59 29.8 [05 23 08 3.6 2.2 2.8 79 N 1 5 200 18
| |
| − | 289 . . . . . . L567 19 01 30.2 [04 30 09 10.1 1.9 4.4 51 N 1 6 200 18
| |
| − | 290 . . . . . . B133 (CB 180) 19 03 37.9 [06 59 05 10.7 4.4 6.9 [43 Y 1 6 200 18
| |
| − | 291 . . . . . . L581 19 04 55.5 [03 59 32 19.6 13.9 16.5 34 N 1 6 200 18
| |
| − | 292 . . . . . . L709 19 11 37.3 16 22 01 1.9 1.9 1.9 0 N 4 6 300 18
| |
| − | 293 . . . . . . DC 13[205 19 13 12.4 [36 42 20 4.6 2.2 3.2 [76 N 3 A 130 20
| |
| − | 294 . . . . . . L763 19 16 45.9 23 21 45 7.6 1.1 2.9 11 N 4 6 250 21
| |
| − | 295 . . . . . . L730-1 19 17 40.5 19 51 09 6.8 1.7 3.4 25 N 2 5 160 22
| |
| − | 296 . . . . . . L655 19 17 47.2 08 23 33 3.2 1.2 2.0 [26 N 4 5 200 18
| |
| − | 297 . . . . . . L673-1 19 17 54.7 11 30 36 2.1 1.7 1.9 [32 Y 3 6 300 23
| |
| − | 298 . . . . . . L730-2 19 18 12.4 19 56 53 2.8 1.1 1.8 66 N 2 5 160 22
| |
| − | 299 . . . . . . L673-12 19 18 39.2 10 48 15 . . . . . . 7.6 . . . Y 3 6 300 23
| |
| − | 300 . . . . . . L771 19 18 46.3 23 25 13 2.8 1.4 2.0 51 Y 4 6 400 18
| |
| − | 301 . . . . . . L673-4 19 18 47.1 11 20 11 3.8 0.8 1.7 55 N 3 6 300 23
| |
| − | 302 . . . . . . L673-5 19 18 53.6 11 27 16 2.7 1.1 1.7 [35 N 3 6 300 23
| |
| − | 303 . . . . . . L673-13 19 19 00.9 10 46 45 . . . . . . 7.6 . . . Y 3 6 300 23
| |
| − | 304 . . . . . . L673-14 19 19 01.9 10 51 27 . . . . . . 7.6 . . . Y 3 6 300 23
| |
| − | 305 . . . . . . L673-6 19 19 06.2 11 30 39 1.6 0.8 1.1 47 N 3 6 300 23
| |
| − | 306 . . . . . . L673-7 19 19 14.3 11 15 30 . . . . . . 7.0 . . . N 4 6 300 23
| |
| − | 307 . . . . . . L673-8 19 19 15.4 11 12 20 . . . . . . 7.0 . . . N 4 6 300 23
| |
| − | 308 . . . . . . L684 19 19 16.1 12 23 25 10.4 5.2 7.4 20 N 2 5 300 18
| |
| − | 309 . . . . . . L673-9 19 19 21.1 11 10 54 . . . . . . 7.0 . . . N 4 6 300 23
| |
| − | 310 . . . . . . L673-10 19 19 32.5 11 14 21 2.2 0.9 1.4 60 N 4 6 300 23
| |
| − | 311 . . . . . . L677-1 19 19 50.0 11 27 19 1.6 0.8 1.1 83 N 3 6 300 23
| |
| − | 312 . . . . . . L677-2 19 19 52.8 11 30 46 3.1 0.6 1.4 [37 N 3 6 300 23
| |
| − | 313 . . . . . . L677-3 19 20 07.5 11 15 30 3.6 1.3 2.2 74 N 3 6 300 23
| |
| − | 314 . . . . . . L677-4 19 20 22.8 11 16 57 1.7 0.8 1.2 83 N 3 6 300 23
| |
| − | 315 . . . . . . L774-1 19 20 44.9 23 19 21 2.5 1.9 2.2 25 N 4 5 200 7
| |
| − | 316 . . . . . . L774-2 19 21 34.2 23 17 18 1.0 1.0 1.0 0 N 4 5 200 7
| |
| − | 317 . . . . . . L769-1 19 21 44.8 23 01 48 . . . . . . 9.4 . . . Y 4 6 200 7
| |
| − | 318 . . . . . . L769-2 19 21 50.4 22 53 23 . . . . . . 6.8 . . . Y 4 6 200 7
| |
| − | 319 . . . . . . L769-3 19 22 21.0 23 02 00 . . . . . . 5.4 . . . Y 4 6 200 7
| |
| − | 320 . . . . . . L769-4 19 22 47.0 22 56 36 . . . . . . 6.2 . . . N 4 6 200 7
| |
| − | 321 . . . . . . L698 19 23 37.5 12 59 48 11.0 1.1 3.5 [2 N 3 6 300 18
| |
| − | 322 . . . . . . L778-1 19 24 19.8 23 53 04 19.6 0.9 4.2 [48 Y 4 6 200 7
| |
| − | 323 . . . . . . L778-2 19 25 22.0 23 39 45 19.6 0.9 4.2 [48 N 4 6 200 7
| |
| − | 324 . . . . . . L778-3 19 25 54.8 23 37 14 19.6 0.9 4.2 [48 N 4 6 200 7
| |
| − | 325 . . . . . . L778-4 19 26 02.6 23 51 12 1.3 1.3 1.3 0 N 4 6 200 7
| |
| − | 326 . . . . . . B335 19 34 35.6 07 27 34 3.2 2.1 2.6 14 Y 4 . . . 250 24
| |
| − | 327 . . . . . . L694-1 19 38 06.5 10 43 33 8.2 2.5 4.5 82 N 4 6 . . . . . .
| |
| − | 328 . . . . . . L694-2 19 38 42.4 10 49 59 . . . . . . 6.4 . . . N 4 6 . . . . . .
| |
| − | 329 . . . . . . L694-3 19 38 54.0 10 43 42 2.4 1.7 2.0 [12 N 4 6 . . . . . .
| |
| − | 242
| |
| − | TABLE 2ÈContinued
| |
| − | a b R PA Distance
| |
| − | Number Source R.A. (1950) Decl. (1950) (arcmin) (arcmin) (arcmin) (deg) EYSO DC Class (pc) References
| |
| − | (1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13)
| |
| − | 330 . . . . . . L758 19 44 12.8 18 54 47 1.6 0.9 1.2 51 N 4 5 400 18
| |
| − | 331 . . . . . . L880 20 11 49.4 40 03 59 7.4 5.7 6.5 [35 N 4 5 700 18
| |
| − | 332 . . . . . . L1152 20 35 26.0 67 43 23 1.6 0.6 1.0 57 Y 1 5 325 25
| |
| − | 333 . . . . . . L1041-1 20 36 05.5 57 33 36 1.7 0.9 1.2 32 Y 1 5 440 23
| |
| − | 334 . . . . . . L1041-2 20 36 05.9 57 38 48 1.8 0.8 1.2 30 N 1 5 440 23
| |
| − | 335 . . . . . . L922-1 20 36 46.5 44 21 24 . . . . . . 2.6 . . . N 4 6 700 18
| |
| − | 336 . . . . . . L922-2 20 37 04.6 44 25 20 . . . . . . 1.8 . . . N 4 6 700 18
| |
| − | 337 . . . . . . L917 20 38 16.6 43 58 37 3.2 0.9 1.7 44 N 3 6 . . . . . .
| |
| − | 338 . . . . . . L918 20 39 02.5 43 54 57 4.9 1.7 2.9 64 N 3 6 . . . . . .
| |
| − | 339 . . . . . . L1049-1 20 39 50.8 57 16 45 3.0 1.4 2.0 50 N 2 6 440 23
| |
| − | 340 . . . . . . L1147 20 39 58.4 67 09 36 6.5 1.3 2.9 44 N 2 3 325 25
| |
| − | 341 . . . . . . L1049-2 20 40 16.8 57 22 57 1.9 0.8 1.2 9 N 3 4 440 23
| |
| − | 342 . . . . . . L896-2 20 40 26.3 39 36 01 . . . . . . 3.0 . . . N 4 5 . . . . . .
| |
| − | 343 . . . . . . L896-1 20 40 28.8 39 42 22 7.4 4.0 5.4 62 N 4 5 . . . . . .
| |
| − | 344 . . . . . . L1148 20 40 38.7 67 09 48 7.1 1.6 3.4 46 N 2 6 325 25
| |
| − | 345 . . . . . . L1155C 20 43 00.0 67 41 47 4.6 3.2 3.8 55 N 2 6 325 25
| |
| − | 346 . . . . . . L1155D 20 43 17.9 67 26 12 4.9 1.4 2.6 43 N 1 6 325 25
| |
| − | 347 . . . . . . L915 20 43 23.0 42 58 52 6.1 3.0 4.3 33 N 4 6 . . . . . .
| |
| − | 348 . . . . . . L1155E 20 43 46.3 67 31 02 2.8 1.4 2.0 32 N 1 6 325 25
| |
| − | 349 . . . . . . L1082C-3 20 47 59.4 60 00 36 4.4 0.6 1.6 47 N 3 5 440 26
| |
| − | 350 . . . . . . L1082C-2 20 48 38.9 60 04 25 2.2 0.6 1.1 49 N 3 5 440 26
| |
| − | 351 . . . . . . L1082C-1 20 50 20.0 60 07 13 2.5 1.7 2.1 43 Y 2 5 440 26
| |
| − | 352 . . . . . . L1082B 20 52 40.7 59 59 59 . . . . . . 8.2 . . . Y 3 5 440 26
| |
| − | 353 . . . . . . L981-1 20 58 36.3 50 08 19 . . . . . . 8.2 . . . N 3 6 700 27
| |
| − | 354 . . . . . . L981-2 20 58 38.0 50 05 09 . . . . . . 8.2 . . . N 3 6 700 27
| |
| − | 355 . . . . . . L971-1 20 59 08.1 49 17 21 2.4 1.1 1.6 24 N 2 5 700 27
| |
| − | 356 . . . . . . L971-2 20 59 15.8 49 07 34 3.0 1.4 2.0 [3 N 2 5 700 27
| |
| − | 357 . . . . . . L981-3 20 59 22.3 50 09 41 . . . . . . 8.2 . . . Y 3 6 700 27
| |
| − | 358 . . . . . . L1174 20 59 22.7 68 01 12 4.7 2.2 3.2 63 Y 2 4 288 25
| |
| − | 359 . . . . . . L1172A-2 21 01 10.8 67 34 34 5.1 3.5 4.2 12 N 1 6 288 25
| |
| − | 360 . . . . . . L1172A-1 21 01 39.6 67 41 59 1.9 1.1 1.4 [34 Y 1 6 288 25
| |
| − | 361 . . . . . . L1172A-3 21 03 22.6 67 29 06 2.5 1.3 1.8 1 N 1 6 288 25
| |
| − | 362 . . . . . . L1063 21 06 44.6 56 06 09 4.4 1.7 2.7 50 N 3 5 800 18
| |
| − | 363 . . . . . . B361-1 21 10 41.7 47 12 05 11.1 11.1 11.1 0 Y 3 . . . 350 28
| |
| − | 364 . . . . . . B361-2 21 10 53.2 47 07 23 11.1 11.1 11.1 0 Y 3 . . . 350 28
| |
| − | 365 . . . . . . L1125-1 21 13 07.8 61 32 26 3.2 1.5 2.2 72 N 2 5 300 1
| |
| − | 366 . . . . . . L1125-2 21 14 07.0 61 27 10 . . . . . . 4.8 . . . Y 2 5 300 1
| |
| − | 367 . . . . . . L944-1 21 14 42.6 42 59 47 3.0 0.8 1.5 [49 N 4 6 . . . . . .
| |
| − | 368 . . . . . . L944-2 21 15 54.0 43 05 41 . . . . . . 2.8 . . . N 4 6 . . . . . .
| |
| − | 369 . . . . . . L944-3 21 16 59.7 43 12 57 0.9 0.6 0.7 27 N 4 6 . . . . . .
| |
| − | 370 . . . . . . L952-1 21 18 08.5 43 18 07 2.0 0.7 1.2 44 N 4 5 . . . . . .
| |
| − | 371 . . . . . . L952-2 21 18 25.0 43 19 59 3.2 0.8 1.6 64 N 4 5 . . . . . .
| |
| − | 372 . . . . . . L953 21 19 31.8 43 08 46 0.9 0.5 0.7 [19 N 4 6 . . . . . .
| |
| − | 373 . . . . . . L1021 21 20 34.8 50 50 17 0.7 0.6 0.6 0 N 4 6 200 29
| |
| − | 374 . . . . . . L1014-1 21 22 20.6 49 56 52 7.0 3.2 4.7 67 N 4 6 200 29
| |
| − | 375 . . . . . . L1014-2 21 22 22.2 49 46 10 2.4 1.1 1.6 [58 N 3 6 200 29
| |
| − | 376 . . . . . . L1099-1 21 34 27.9 57 13 18 1.7 0.8 1.2 81 N 4 5 . . . . . .
| |
| − | 377 . . . . . . L973 21 35 16.3 43 06 57 2.2 0.9 1.4 [8 Y 3 5 . . . . . .
| |
| − | 378 . . . . . . L1111 21 38 53.6 57 34 24 3.7 2.4 3.0 [42 N 4 6 150 29
| |
| − | 379 . . . . . . L1121 21 39 10.0 58 02 33 2.4 1.7 2.0 25 Y 4 5 . . . . . .
| |
| − | 380 . . . . . . L1103-1 21 39 49.8 56 23 32 4.4 2.4 3.2 54 N 4 6 . . . . . .
| |
| − | 381 . . . . . . L1103-2 21 40 41.0 56 30 07 2.1 1.0 1.4 21 N 4 6 150 29
| |
| − | 382 . . . . . . L1113-2 21 42 45.4 56 57 33 2.4 1.6 2.0 64 N 4 5 150 29
| |
| − | 383 . . . . . . L1113-1 21 42 56.7 56 56 25 0.9 0.9 0.9 0 N 4 5 150 29
| |
| − | 384 . . . . . . L1031C 21 44 35.9 47 03 42 7.3 2.8 4.5 [87 Y 3 5 900 30
| |
| − | 385 . . . . . . L1139-1 21 53 14.7 58 20 59 2.1 0.9 1.4 [48 N 2 5 . . . . . .
| |
| − | 386 . . . . . . L1139-2 21 53 47.3 58 20 14 4.6 1.1 2.2 55 Y 2 5 . . . . . .
| |
| − | 387 . . . . . . L1143 21 57 03.0 58 42 25 7.3 2.1 3.9 46 Y 4 6 . . . . . .
| |
| − | 388 . . . . . . L1166 22 03 46.7 59 19 07 1.9 0.9 1.3 59 N 4 6 . . . . . .
| |
| − | 389 . . . . . . L1164 22 05 07.7 58 51 15 . . . . . . 7.4 . . . Y 4 6 . . . . . .
| |
| − | 390 . . . . . . L1235 22 14 44.4 73 08 05 6.3 3.5 4.7 67 N 2 6 200 3
| |
| − | 391 . . . . . . L1195 22 25 18.1 61 01 06 4.6 1.9 3.0 13 N 2 5 . . . . . .
| |
| − | 392 . . . . . . L1221 22 26 38.4 68 45 48 6.2 2.4 3.9 43 Y 2 5 200 23
| |
| − | 393 . . . . . . L1251A-2 22 26 46.5 74 58 10 3.3 2.2 2.7 54 N 3 5 300 31
| |
| − | 394 . . . . . . L1185 22 27 27.6 58 53 30 4.1 1.6 2.6 75 N 3 6 . . . . . .
| |
| − | 395 . . . . . . L1251A-1 22 30 00.8 74 57 04 8.2 5.1 6.5 [67 Y 2 5 300 31
| |
| − | 243
| |
| − | 200 400 600 800 1000
| |
| − | 5000
| |
| − | 5500
| |
| − | 6000
| |
| − | 6500
| |
| − | 7000
| |
| − | 0 1 2 3 4 5
| |
| − | 0
| |
| − | 0.2
| |
| − | 0.4 Lynds 5
| |
| − | 0
| |
| − | 0.2
| |
| − | 0.4 Lynds 6
| |
| − | 0
| |
| − | 0.2
| |
| − | 0.4 Hartley A
| |
| − | 244 LEE & MYERS
| |
| − | TABLE 2ÈContinued
| |
| − | a b R PA Distance
| |
| − | Number Source R.A. (1950) Decl. (1950) (arcmin) (arcmin) (arcmin) (deg) EYSO DC Class (pc) References
| |
| − | (1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13)
| |
| − | 396 . . . . . . L1197 22 35 08.0 58 41 46 4.3 1.2 2.3 [56 N 4 6 . . . . . .
| |
| − | 397 . . . . . . L1251 22 36 26.0 74 54 46 7.1 1.9 3.7 52 N 1 5 300 31
| |
| − | 398 . . . . . . L1229 23 12 16.8 61 46 47 3.8 1.4 2.3 24 N 4 5 . . . . . .
| |
| − | 399 . . . . . . L1234 23 15 47.5 62 10 15 1.9 0.8 1.2 [73 N 4 6 . . . . . .
| |
| − | 400 . . . . . . CB 243 (L1246) 23 23 07.2 63 19 48 3.3 1.1 1.9 [73 Y 4 6 . . . . . .
| |
| − | 401 . . . . . . L1262A (CB 244) 23 23 47.7 74 01 29 4.7 2.1 3.1 [73 Y 2 6 200 3
| |
| − | 402 . . . . . . CB 246 (L1253) 23 54 10.8 58 17 29 3.2 2.1 2.6 [48 N 3 6 140 3
| |
| − | 403 . . . . . . L1263 23 54 54.2 64 32 27 2.5 1.3 1.8 [10 N 1 5 . . . . . .
| |
| − | 404 . . . . . . L1271-1 23 57 32.6 67 05 07 11.4 1.1 3.5 55 N 4 5 . . . . . .
| |
| − | 405 . . . . . . L1271-2 23 58 20.7 66 52 29 2.1 1.1 1.5 31 Y 4 5 . . . . . .
| |
| − | 406 . . . . . . L1271-3 23 59 15.3 67 01 48 2.8 2.2 2.5 [51 N 4 5 . . . . . .
| |
| − | NOTES.ÈThese 406 sources are positions showing local intensity minima in the STScI Digitized Sky Survey (DSS). Cols. (1)È(4) : Sequential numbers,
| |
| − | source names, and their coordinates. Cols. (5) and (6) : a and b are sizes of major and minor axis of FWHM of selected cores, respectively. Col. (7) : Geometric
| |
| − | mean (ab)0.5 for the cores whose a and b are measured, or the equivalent diameter 2](A/n)0.5 for the cores in which a and b are not measured owing to its
| |
| − | irregularity. Col. (8) : Position angle of the core. Col. (9) : N, starless cores ; Y, cores with embedded YSOs; PM, cores with preÈmain-sequence (PMS) stars ;
| |
| − | and PM*, PMSs that are determined by optical spectroscopy (Herbig & Bell 1988). Col. (10) : Darkness contrast of the opaque core to the background, where
| |
| − | 1 corresponds to the least dark and 4 to the most dark. Col. (11) : Lynds opacity class and Hartley A class. Col. (12) : Distances to the cores. Col. (13) :
| |
| − | References for core distances.
| |
| − | REFERENCES.È(1) Lindblad et al. 1973, Lindblad ring ; (2) Herbig & Jones 1983, Per OB2; (3) Snell 1981; (4) Elias 1978b, Taurus; (5) Maddalena et al. 1986,
| |
| − | Orion A, B; (6) Murdin & Penston 1977; (7) Goodman et al. 1993; (8) Bok & McCarthy 1974; (9) Carballo & Sahu 1994; (10) Harjunpaa, Lijiestrom, &
| |
| − | Mattila 1991, Vela; (11) Schwartz 1991, Cha I ; (12) Rogers 1960, Coal Sack; (13) Hetem et al. 1988, Musca; (14) Gauvin & Strom 1992, Cha II, III ; (15)
| |
| − | Neckel & Klare 1980, G317-4; (16) Murphy 1985, Lupus; (17) Chini 1981, Ophiuchus; (18) Dame & Thaddeus 1985, Aquila Rift (200 pc), Cloud B (300 pc),
| |
| − | Cloud C (500 pc), Vul Rift (400 pc), Cyg Rift (700 pc), Cyg OB7 (800 pc) ; (19) Beichman et al. 1986; (20) Marraco & Rydgren 1981; (21) Cohen & Kuhi 1979;
| |
| − | (22) Frerking & Langer 1982; (23) Felli, Palagi, & Tofani 1992; (24) Tomita, Saito, & Ohtani 1979; (25) Straizys et al. 1992; (26) Viotti 1969; (27) Clark 1986;
| |
| − | (28) Schmidt 1975; (29) Leung, Kutner, &Mead 1982; (30) Elias 1978a; (31) Kun & Prusti 1993; (32) Graham & Frogel 1985, Norma.
| |
| − | 4@ with a mean (^s.e.m.) of 3.@7(^0.1). This distribution is
| |
| − | similar to that found by previous study of CB. The size
| |
| − | distribution of starless cores, which comprise a majority,
| |
| − | resembles the size distribution of all cores, while the size of
| |
| − | cores with EYSOs is uniformly distributed between 1@ and
| |
| − | 8@. The interesting thing is that the mean size (5.@1^0.@4) of
| |
| − | the cores with EYSOs is larger than that (3.@3^0.@1) of starless
| |
| − | cores.
| |
| − | We also Ðnd a corresponding di†erence in the distribution
| |
| − | of the linear sizes, as illustrated in Figure 5. Distances
| |
| − | (Table 2, col. [12]) of cores for determination of the linear
| |
| − | sizes have been obtained from numerous papers (see refer-
| |
| − | FIG. 2.ÈExample of a cut-proÐle of L1622 cloud. This cut-proÐle was
| |
| − | obtained by crossing two intensity minima of L1622A and L1622B. The
| |
| − | angular size for 1 pixel in the abscissa is about 0A.6. The data value (DN) is
| |
| − | on a scale of photographic density (c) in the expression of c\DN/6553.4
| |
| − | (Postman 1996). The data values (IB and IC) of DSS for the background
| |
| − | and the core are approximately adopted from this proÐle.
| |
| − | ences listed in Table 2) referred to by Dame et al. (1987),
| |
| − | BM, Vilas-Boas et al. (1994), Hilton & Lahulla (1995), and
| |
| − | Chen et al. (1997). We adopted the distances given by those
| |
| − | papers if our sources are in a vicinity (within 1¡) of the
| |
| − | FIG. 3.ÈRelation of the darkness contrast (DC) to Lynds class 5 and 6
| |
| − | and HMSTG class A. Lynds 6 and HMSTG A clouds more likely have a
| |
| − | DC of 3 or 4 than Lynds 5 clouds.
| |
| − | TABLE 3
| |
| − | IRAS POINT SOURCES AND PMS STARS ASSOCIATED WITH OPTICALLY SELECTED CORES
| |
| − | F12km F25km F60km F100km Core Name IRAS or PMSa Name R.A. (1950) Decl. (1950) (Jy) (Jy) (Jy) (Jy)
| |
| − | L1358-1 . . . . . . . . . . . . . . . . . . 02514]6902 02 51 24.0 69 02 36 0.76 0.25L 0.40L 6.61
| |
| − | CB 17 . . . . . . . . . . . . . . . . . . . . 04005]5647 04 00 30.8 56 47 59 0.44L 0.25L 0.90 5.81
| |
| − | L1495-3 . . . . . . . . . . . . . . . . . . 04154]2823 04 15 25.7 28 23 56 0.45 1.02 1.96 7.80L
| |
| − | L1506A . . . . . . . . . . . . . . . . . . 04207]2449 04 20 39.0 24 49 24 0.46 0.65 0.86 1.92
| |
| − | B217-1 . . . . . . . . . . . . . . . . . . . 04249]2612 04 24 53.2 26 12 39 0.36L 1.33 4.61 9.29
| |
| − | L1524-2 . . . . . . . . . . . . . . . . . . 04264]2426 04 26 21.7 24 26 26 14.86 38.73 59.70 47.42
| |
| − | L1524-1 . . . . . . . . . . . . . . . . . . 04265]2433 04 26 28.0 24 33 23 0.44 2.91 5.40 9.12L
| |
| − | L1524-3 . . . . . . . . . . . . . . . . . . 04264]2426 04 26 21.7 24 26 26 14.86 38.73 59.70 47.42
| |
| − | TMC 2-2 . . . . . . . . . . . . . . . . . 04288]2417 04 28 48.7 24 17 54 0.33 1.03 2.56 5.70
| |
| − | TMC 2A . . . . . . . . . . . . . . . . . 04292]2422 04 29 13.2 24 22 39 1.06 3.98 7.18 9.82
| |
| − | TMC 2-1 . . . . . . . . . . . . . . . . . 04292]2422 04 29 13.2 24 22 39 1.06 3.98 7.18 9.82
| |
| − | B18-4 . . . . . . . . . . . . . . . . . . . . . 04325]2402 04 32 31.6 24 02 08 0.25L 2.11 12.82 22.28
| |
| − | L1527A-1 . . . . . . . . . . . . . . . . 04354]2604 04 35 23.9 26 04 51 1.91 3.87 5.92 6.49
| |
| − | L1534 . . . . . . . . . . . . . . . . . . . . 04363]2539 04 36 16.2 25 39 07 0.55 0.72 0.40L 2.01L
| |
| − | L1534 . . . . . . . . . . . . . . . . . . . . 04365]2535 04 36 31.0 25 35 52 1.19 8.63 35.97 39.08
| |
| − | L1534 . . . . . . . . . . . . . . . . . . . . 04369]2539 04 36 54.6 25 39 17 5.01 6.79 7.24 18.20
| |
| − | TMC 1-1 . . . . . . . . . . . . . . . . . 04381]2540 04 38 07.6 25 40 48 0.44 2.68 10.28 13.93
| |
| − | TMC 1C . . . . . . . . . . . . . . . . . 04386]2550 04 38 34.2 25 50 43 0.54 1.54 2.88 8.02L
| |
| − | B25A . . . . . . . . . . . . . . . . . . . . . 05418]0907 05 41 45.3 09 07 40 0.28 2.91 25.59 74.47
| |
| − | L1622B . . . . . . . . . . . . . . . . . . . 05523]0146 05 52 17.2 01 46 41 0.34L 0.31 1.45 31.33
| |
| − | L1645 . . . . . . . . . . . . . . . . . . . . 06053[0533 06 05 16.3 [05 33 49 0.25L 0.60 13.06 22.28
| |
| − | L1578-1, L1578-2 . . . . . . . Bretz 34 06 05 42.5 18 08 21 . . . . . . . . . . . .
| |
| − | V14 . . . . . . . . . . . . . . . . . . . . . . . 08077[35561 08 07 40.2 [35 56 07 0.63 3.73 18.20 47.42
| |
| − | DC 2573[25-1 . . . . . . . . . 08153[3945 08 15 16.6 [39 45 44 0.41 1.24 1.47 17.70L
| |
| − | DC 2660[75-2 . . . . . . . . . 08196[4931 08 19 37.1 [49 31 13 0.25L 7.05 53.46 74.47L
| |
| − | DC 2674[75 . . . . . . . . . . . . 08243[5050 08 24 16.5 [50 50 44 0.82 6.31 26.06 58.08
| |
| − | DC 2672[72 . . . . . . . . . . . . 08251[5030 08 25 03.4 [50 30 34 0.25L 0.25L 1.19 17.06
| |
| − | DC 2977[28 . . . . . . . . . . . . 11591[64521 11 59 03.1 [64 52 11 0.25L 6.55 77.27 192.31
| |
| − | Ch 7 . . . . . . . . . . . . . . . . . . . . . . 12496[7650 12 49 38.0 [76 50 45 39.45 85.51 104.71 87.10
| |
| − | Ch 7 . . . . . . . . . . . . . . . . . . . . . . 12501[7658 12 50 03.0 [76 58 49 0.25L 1.02 2.70 5.35L
| |
| − | Ch 19-1 . . . . . . . . . . . . . . . . . . 12571[7654 12 57 07.6 [76 54 31 0.31L 0.52 0.86 5.81
| |
| − | DC 3038[142 . . . . . . . . . . 13037[76442 13 03 41.4 [76 44 03 0.25L 1.05 6.37 22.49
| |
| − | DC 3148[51 . . . . . . . . . . . . 14451[6502 14 45 07.6 [65 02 55 1.26 1.46 4.66 22.70
| |
| − | DC 3379]164 . . . . . . . . . . 15363[3436 15 36 15.2 [34 36 32 0.56 0.82 0.40L 13.30L
| |
| − | DC 3388]165-4 . . . . . . . . 15390[3400 15 39 01.6 [34 00 32 0.25L 0.29L 0.76 6.73
| |
| − | DC 3388]165-4,5 . . . . . . 15399[33592 15 39 51.2 [33 59 36 0.25L 1.28 15.28 41.30
| |
| − | DC 3392]161-1 . . . . . . . . 15420[3408 15 42 01.3 [34 08 09 2.58 3.98 7.94 24.43
| |
| − | DC 3390]150 . . . . . . . . . . 15449[3506 15 44 51.6 [35 06 36 0.91 1.98 1.96 12.47L
| |
| − | DC 3386]119-2 . . . . . . . . 15534[3740 15 53 24.5 [37 40 34 2.44 4.53 4.97 10.47L
| |
| − | DC 3397]92-1 . . . . . . . . . 16054[3857 16 05 25.6 [38 57 50 0.60L 0.72 6.08 63.68
| |
| − | DC 3397]92-1 . . . . . . . . . 16059[3850 16 05 56.2 [38 50 28 0.26L 0.27L 1.18 8.24
| |
| − | DC 3397]92-1 . . . . . . . . . 16065[3903 16 06 27.6 [39 03 30 0.38 0.54 0.61 24.66L
| |
| − | DC 3397]92-1,2,3 . . . . . . 16073[3900 16 07 17.0 [39 00 24 0.25L 0.28L 0.84 11.69
| |
| − | DC 3397]92-2 . . . . . . . . . 16059[3850 16 05 56.2 [38 50 28 0.26L 0.27L 1.18 8.24
| |
| − | DC 3397]92-2,3 . . . . . . . . 16065[3903 16 06 27.6 [39 03 30 0.38 0.54 0.61 24.66L
| |
| − | DC 3402]90-1,2,3 . . . . . . 16082[38523 16 08 12.7 [38 52 25 4.92 3.44 0.90 5.01L
| |
| − | L1681A . . . . . . . . . . . . . . . . . . 16226[2417 16 22 36.0 [24 17 56 4.02 10.28 2.56L 26.55L
| |
| − | L1681A . . . . . . . . . . . . . . . . . . 16226[2408 16 22 38.7 [24 08 52 2.21 3.05 25.12L 794.33L
| |
| − | L1681A . . . . . . . . . . . . . . . . . . 16228[2418 16 22 47.9 [24 18 48 1.91 3.05 2.94L 29.92L
| |
| − | L1681A . . . . . . . . . . . . . . . . . . 16232[2427 16 23 09.6 [24 27 35 3.47L 52.48 469.89L 1018.59
| |
| − | L1681A . . . . . . . . . . . . . . . . . . 16234[2409 16 23 22.7 [24 09 30 3.44 3.80 2.81L 24.21L
| |
| − | L1681A . . . . . . . . . . . . . . . . . . 16234[2436 16 23 25.0 [24 36 58 0.91 1.49 8.24 28.31L
| |
| − | L1681A . . . . . . . . . . . . . . . . . . 16235[2416 16 23 31.5 [24 16 56 34.99 265.46 2187.76 4655.86
| |
| − | L1681A . . . . . . . . . . . . . . . . . . 16237[2428 16 23 44.2 [24 28 07 2.88 7.80 148.59L 299.23
| |
| − | L1681A . . . . . . . . . . . . . . . . . . 16239[2428 16 23 53.5 [24 28 12 4.45 19.05 197.70L 787.05L
| |
| − | L1681A . . . . . . . . . . . . . . . . . . 16239[2438 16 23 56.6 [24 38 52 3.56 6.92 8.47 39.81L
| |
| − | L1681A . . . . . . . . . . . . . . . . . . 16241[2430 16 24 03.6 [24 30 43 39.45 73.79 197.70 586.14
| |
| − | L1681A . . . . . . . . . . . . . . . . . . 16243[2422 16 24 15.7 [24 22 06 2.09L 6.55 64.27L 218.78
| |
| − | L1681A . . . . . . . . . . . . . . . . . . 16244[24321 16 24 26.2 [24 32 53 9.91 67.30 111.69L 349.95
| |
| − | L1681A . . . . . . . . . . . . . . . . . . 16246[2423 16 24 34.7 [24 23 51 7.80 46.56 65.46L 224.91L
| |
| − | L1681A . . . . . . . . . . . . . . . . . . 16246[2415 16 24 38.1 [24 15 22 0.93 1.51 6.43L 165.96L
| |
| − | L1681A . . . . . . . . . . . . . . . . . . 16246[2436 16 24 38.6 [24 36 36 1.63 2.94 4.57 31.05L
| |
| − | L1681A . . . . . . . . . . . . . . . . . . 16248[2424 16 24 47.7 [24 24 59 5.70 17.22 65.46L 35.65
| |
| − | L1681A . . . . . . . . . . . . . . . . . . 16253[2429 16 25 20.4 [24 29 55 0.25L 0.42L 2.91 16.29
| |
| − | L1681A . . . . . . . . . . . . . . . . . . 16257[2421 16 25 43.4 [24 21 50 0.67 0.73 2.07 52.48L
| |
| − | TABLE 3ÈContinued
| |
| − | F12km F25km F60km F100km Core Name IRAS or PMSa Name R.A. (1950) Decl. (1950) (Jy) (Jy) (Jy) (Jy)
| |
| − | L1696B-1 . . . . . . . . . . . . . . . . 16242[2412 16 24 10.2 [24 12 34 2.27 19.77 33.73 165.96L
| |
| − | L1696B-1 . . . . . . . . . . . . . . . . 16246[2415 16 24 38.1 [24 15 22 0.93 1.51 6.43L 165.96L
| |
| − | L1696B-1 . . . . . . . . . . . . . . . . 16257[2421 16 25 43.4 [24 21 50 0.67 0.73 2.07 52.48L
| |
| − | L1709B-1 . . . . . . . . . . . . . . . . 16286[2355 16 28 34.7 [23 55 13 1.19 3.73 9.46 60.81L
| |
| − | L1709B-1 . . . . . . . . . . . . . . . . 16294[2358 16 29 21.3 [23 58 57 0.25L 0.71L 1.18 15.56
| |
| − | L1689B2 . . . . . . . . . . . . . . . . . 16293[24221 16 29 20.9 [24 22 13 0.25L 1.82 255.86 1028.02
| |
| − | L1689B4, L1689B1 . . . . . . 16306[2425 16 30 33.2 [24 25 21 0.37L 0.39L 1.49 31.05
| |
| − | DC 3387]18 . . . . . . . . . . . . 16307[4455 16 30 39.9 [44 55 13 1.69L 0.62 2.81 38.73L
| |
| − | L1689B5 . . . . . . . . . . . . . . . . . 16306[2425 16 30 33.2 [24 25 21 0.37L 0.39L 1.49 31.05
| |
| − | L1689B5 . . . . . . . . . . . . . . . . . 16314[2439 16 31 23.9 [24 39 17 0.25L 0.47L 1.11 15.00
| |
| − | L43D . . . . . . . . . . . . . . . . . . . . . 16316[1540 16 31 37.7 [15 40 52 1.50 6.03 35.32 64.27
| |
| − | L1689B1 . . . . . . . . . . . . . . . . . 16314[2439 16 31 23.9 [24 39 17 0.25L 0.47L 1.11 15.00
| |
| − | L43E . . . . . . . . . . . . . . . . . . . . . 16316[1540 16 31 37.7 [15 40 52 1.50 6.03 35.32 64.27
| |
| − | L260 . . . . . . . . . . . . . . . . . . . . . . 16442[0930 16 44 14.2 [09 30 03 0.57 3.31 7.80 7.52
| |
| − | L255-1 . . . . . . . . . . . . . . . . . . . . 16451[0953 16 45 07.0 [09 53 20 0.25L 0.32L 0.60 12.82
| |
| − | L234E2 . . . . . . . . . . . . . . . . . . . 16452[1046 16 45 10.0 [10 45 53 0.25L 0.34L 0.99 7.11
| |
| − | L158-3 . . . . . . . . . . . . . . . . . . . . 16455[1405 16 45 32.0 [14 05 31 0.63 0.90 1.22 13.30L
| |
| − | L158-4 . . . . . . . . . . . . . . . . . . . . 16464[1407 16 46 25.2 [14 07 48 0.60L 0.36L 0.63 6.49
| |
| − | L162-1 . . . . . . . . . . . . . . . . . . . . 16459[1411 16 45 54.7 [14 11 20 1.41 1.91 2.33L 6.49
| |
| − | L162-1 . . . . . . . . . . . . . . . . . . . . 16464[1407 16 46 25.2 [14 07 48 0.60L 0.36L 0.63 6.49
| |
| − | CB 68-3 . . . . . . . . . . . . . . . . . . 16534[1557 16 53 24.6 [15 57 27 0.39 1.41 1.94 12.13L
| |
| − | CB 68-1 . . . . . . . . . . . . . . . . . . 16545[1604 16 54 27.2 [16 04 48 0.25L 1.49 19.41 33.73
| |
| − | L100 . . . . . . . . . . . . . . . . . . . . . . 17131[2053 17 13 03.9 [20 53 39 0.38L 1.22L 4.13 14.59
| |
| − | L100 . . . . . . . . . . . . . . . . . . . . . . 17134[20563 17 13 22.4 [20 56 13 8.95 5.60 0.95 16.75L
| |
| − | L1774 . . . . . . . . . . . . . . . . . . . . . 17194[2705 17 19 22.9 [27 05 56 0.72L 6.19 6.73 10.86L
| |
| − | DC 3463-41 . . . . . . . . . . . . . . 17229[42373 17 22 53.4 [42 37 19 1.47 0.79 1.53 17.06
| |
| − | L425 . . . . . . . . . . . . . . . . . . . . . . 17442[0433 17 44 11.7 [04 33 31 0.41 2.31 8.17 9.64
| |
| − | L323(CB 125) . . . . . . . . . . . . 18122[1818 18 12 14.2 [18 18 30 3.91 12.13 58.08L 625.17L
| |
| − | L483-1 . . . . . . . . . . . . . . . . . . . . 18148[04401 18 14 50.6 [04 40 49 0.25L 6.92 88.72 165.96
| |
| − | L406 . . . . . . . . . . . . . . . . . . . . . . 18231[1144 18 23 04.5 [11 44 50 7.38 10.67 21.68L 440.55L
| |
| − | L406 . . . . . . . . . . . . . . . . . . . . . . 18233[1154 18 23 15.2 [11 54 22 15.14 88.72 937.56 2857.59
| |
| − | B133 . . . . . . . . . . . . . . . . . . . . . . 19038[0659 19 03 48.0 [06 59 47 0.25L 0.50 0.98 9.82
| |
| − | L673-1 . . . . . . . . . . . . . . . . . . . . 19179]1129 19 17 54.0 11 29 56 0.27L 1.06 3.94 18.54
| |
| − | L673-12 . . . . . . . . . . . . . . . . . . 19184]1055 19 18 24.2 10 55 15 3.73 5.45 3.70L 9.73
| |
| − | L673-12 . . . . . . . . . . . . . . . . . . 19190]1048 19 19 00.4 10 48 12 1.13 3.40 7.80 61.38L
| |
| − | L771 . . . . . . . . . . . . . . . . . . . . . . 19187]2325 19 18 39.8 23 25 50 0.25L 0.25L 1.04 6.61
| |
| − | L673-13 . . . . . . . . . . . . . . . . . . 19190]1048 19 19 00.4 10 48 12 1.13 3.40 7.80 61.38L
| |
| − | L673-14 . . . . . . . . . . . . . . . . . . 19190]1048 19 19 00.4 10 48 12 1.13 3.40 7.80 61.38L
| |
| − | L774-1, L769-1 . . . . . . . . . . 19216]2302 19 21 35.9 23 02 54 0.51L 0.26 1.13 7.38L
| |
| − | L774-1 . . . . . . . . . . . . . . . . . . . . 19219]2300 19 21 54.1 23 00 46 0.25L 0.25L 2.78 12.47
| |
| − | L774-1 . . . . . . . . . . . . . . . . . . . . 19221]2300 19 22 08.3 23 00 05 0.54 1.22 1.57 5.81L
| |
| − | L769-2 . . . . . . . . . . . . . . . . . . . . 19221]2300 19 22 08.3 23 00 05 0.54 1.22 1.57 5.81L
| |
| − | L769-3 . . . . . . . . . . . . . . . . . . . . 19221]2300 19 22 08.3 23 00 05 0.54 1.22 1.57 5.81L
| |
| − | L778-1 . . . . . . . . . . . . . . . . . . . . 19244]2352 19 24 23.8 23 52 10 0.33L 0.25L 3.05 8.63
| |
| − | L778-1 . . . . . . . . . . . . . . . . . . . . 19244]2350 19 24 23.9 23 50 56 0.33 0.57 0.40L 9.12
| |
| − | B335 . . . . . . . . . . . . . . . . . . . . . . 19346]07271 19 34 35.3 07 27 24 0.25L 0.25L 8.32 42.07
| |
| − | L1152 . . . . . . . . . . . . . . . . . . . . . 20353]6742 20 35 20.1 67 42 30 0.25L 0.34 4.09 7.11
| |
| − | L1041-1 . . . . . . . . . . . . . . . . . . 20361]5733 20 36 08.7 57 33 40 0.25L 1.16 11.38 26.55
| |
| − | L1082C-1 . . . . . . . . . . . . . . . . 20503]6006 20 50 19.6 60 06 41 0.25L 0.30 1.54 13.80L
| |
| − | L1082B . . . . . . . . . . . . . . . . . . . 20521]6003 20 52 04.7 60 03 14 0.49 1.36 2.47 6.25
| |
| − | L1082B . . . . . . . . . . . . . . . . . . . 20527]5958 20 52 41.0 59 58 21 0.39L 0.25L 1.36 5.65
| |
| − | L981-3 . . . . . . . . . . . . . . . . . . . . 20595]5009 20 59 32.3 50 09 53 1.15 2.81 6.55 39.81L
| |
| − | L1174 . . . . . . . . . . . . . . . . . . . . . 20597]6800 20 59 42.1 68 00 13 0.25L 0.82 4.49 54.95L
| |
| − | L1172A-1 . . . . . . . . . . . . . . . . 21017]6742 21 01 44.2 67 42 24 0.28L 0.26 1.33 5.81
| |
| − | B361-1,2 . . . . . . . . . . . . . . . . . . 21107]4712 21 10 41.0 47 12 01 0.25L 0.78 15.70 39.08
| |
| − | L1125-2 . . . . . . . . . . . . . . . . . . 21137]6126 21 13 44.5 61 26 52 0.26 0.53 3.66 23.77
| |
| − | L1014-1 . . . . . . . . . . . . . . . . . . 21221]4955 21 22 08.7 49 55 09 0.42L 0.19 0.69L 8.71
| |
| − | L973 . . . . . . . . . . . . . . . . . . . . . . 21352]4307 21 35 14.4 43 07 05 1.02 3.56 6.85 13.93
| |
| − | L1121 . . . . . . . . . . . . . . . . . . . . . 21392]5802 21 39 10.3 58 02 29 0.56 8.87 144.54 424.62
| |
| − | L1031C . . . . . . . . . . . . . . . . . . . 21446]4704 21 44 35.6 47 04 21 0.25L 0.34L 0.86 13.43
| |
| − | L1139-2 . . . . . . . . . . . . . . . . . . 21539]5821 21 53 55.2 58 21 25 0.25L 0.25L 5.70 28.84
| |
| − | L1143 . . . . . . . . . . . . . . . . . . . . . 21570]5842 21 56 58.8 58 42 46 0.51 1.64 4.45 4.74
| |
| − | L1164 . . . . . . . . . . . . . . . . . . . . . 22052]5848 22 05 09.8 58 48 06 0.25L 5.20 51.52 93.76
| |
| − | L1221 . . . . . . . . . . . . . . . . . . . . . 22266]6845 22 26 37.2 68 45 52 0.98 3.53 12.36 25.82
| |
| − | L1251A-1 . . . . . . . . . . . . . . . . 22291]7458 22 29 03.3 74 58 51 0.28L 0.38 0.73 9.12L
| |
| − | CB 243 . . . . . . . . . . . . . . . . . . . 23229]6320 23 22 52.9 63 20 04 0.26 0.74 2.07 7.94
| |
| − | 0 10 20
| |
| − | 0
| |
| − | 20
| |
| − | 40
| |
| − | 60
| |
| − | 80
| |
| − | N=348
| |
| − | All Cores
| |
| − | 0
| |
| − | 20
| |
| − | 40
| |
| − | 60
| |
| − | 80
| |
| − | N=275
| |
| − | Starless Cores
| |
| − | 0
| |
| − | 20
| |
| − | 40
| |
| − | 60
| |
| − | 80
| |
| − | N=72
| |
| − | Cores with EYSOs
| |
| − | 0 0.5 1 1.5
| |
| − | 0
| |
| − | 20
| |
| − | 40
| |
| − | 60
| |
| − | N=292
| |
| − | All Cores
| |
| − | 0
| |
| − | 20
| |
| − | 40
| |
| − | 60
| |
| − | N=229
| |
| − | Starless Cores
| |
| − | 0
| |
| − | 20
| |
| − | 40
| |
| − | 60
| |
| − | N=63
| |
| − | Cores with EYSOs
| |
| − | OPTICALLY SELECTED CORES 247
| |
| − | TABLE 3ÈContinued
| |
| − | F12km F25km F60km F100km Core Name IRAS or PMSa Name R.A. (1950) Decl. (1950) (Jy) (Jy) (Jy) (Jy)
| |
| − | L1262A . . . . . . 23238]7401 23 23 48.8 74 01 08 0.25L 0.77 9.64 15.14
| |
| − | L1271-2 . . . . . . 23585]6653 23 58 30.1 66 53 53 1.54 2.25 40.55L 55.46L
| |
| − | NOTE.ÈUnits of right ascension are hours, minutes, and seconds, and units of declination are degrees, arcminutes,
| |
| − | and arcseconds.
| |
| − | a Names with 1 and 2 added were previously known as class 0 YSOs by Bachiller 1996 and Mardones et al. 1997,
| |
| − | respectively. Names with 3 and 4 added were identiÐed as PMS by the criteria of Weintraub 1990 and the PMS catalog
| |
| − | of Herbig & Bell 1988, respectively
| |
| − | clouds whose distances are known and/or LSR velocities
| |
| − | [known from a recent CS (2È1) and N (1È0) survey; 2H`
| |
| − | Lee, Myers, & Tafalla 1999] of our sources are within ^2
| |
| − | km s~1 of those of the known clouds. Linear sizes of more
| |
| − | than 80% of all the cores are between 0.05 and 0.35 pc and
| |
| − | the mean size (^s.e.m.) of the cores is about 0.24 (^0.01) pc.
| |
| − | Most (about 70%) of the cores with EYSOs have sizes of
| |
| − | 0.15È0.4 pc with a mean of 0.33 (^0.03) pc, while most
| |
| − | (more than 85%) of starless cores have sizes of 0.05È0.35 pc
| |
| − | with a mean of 0.21 (^0.01) pc. The sizes of cores with
| |
| − | EYSOs clearly tend to be larger than those of starless cores.
| |
| − | Interestingly, this tendency is similar to that of the distribution
| |
| − | of the sizes of NH cores by BM. We investigated wh3ether this apparent di†erence in core
| |
| − | sizes originates from any distance e†ect. Figure 6 shows the
| |
| − | distribution of distances of starless cores and of cores with
| |
| − | EYSOs, indicating no signiÐcant di†erence in the distances
| |
| − | between these two groups. Moreover the mean distances
| |
| − | are nearly same within the range of error, about 227^8 pc
| |
| − | for starless cores and about 244^19 pc for cores with
| |
| − | EYSOs. Thus it seems real that the cores with EYSOs are
| |
| − | usually larger than starless cores by a typical factor of 1.6.
| |
| − | FIG. 4.ÈDistribution of the apparent angular size of cores. The positions
| |
| − | of mean angular sizes (mean^s.e.m.) of 3.@7^0@.1, 3.@3^0.@1, and
| |
| − | 5.@1^0.@4 for all cores, starless cores, and cores with EYSOs, respectively,
| |
| − | are marked with vertical bars in each panel.
| |
| − | This may mean that larger cores have a greater likelihood
| |
| − | to form stars since they have more initial mass, or alternatively
| |
| − | cores with EYSOs may be larger because they have
| |
| − | been growing for a longer time.
| |
| − | The aspect ratio (a/b) of cores ranges mostly between 1.5
| |
| − | and 2.5 for both starless cores and cores with EYSOs (Fig.
| |
| − | 7). The mean (^s.e.m.) aspect ratios are 2.4^0.1, 2.2^0.2,
| |
| − | and 2.4^0.1 for starless cores, cores with YSOs, and all
| |
| − | cores, respectively. The most elongated cores are L1271-1
| |
| − | (10.4) and L698 (10.0). Our measured aspect ratios are
| |
| − | slightly larger than the value of CB (2.0) for their cores, the
| |
| − | value of Wood et al. (1994) (1.98) for the IRAS cores, and
| |
| − | the value of BM (1.9^0.12) for their 41 NH cores. Our measurement for the aspect ratio of cores co3nÐrms that
| |
| − | most cores are more likely elongated than spherical.
| |
| − | 2.2.3. Spatial Distribution of Selected Cores
| |
| − | Figure 8 shows the spatial distribution of cores in galactic
| |
| − | coordinates. This indicates that the cores have been uniformly
| |
| − | selected from all regions. There seems to be no indication
| |
| − | that the distribution of cores with EYSOs is di†erent
| |
| − | from that of starless cores. In this Ðgure we marked Ðve
| |
| − | distinctive star-forming regions in boxes that contain cores
| |
| − | FIG. 5.ÈDistribution of the linear size of cores. The positions of mean
| |
| − | linear sizes (mean^s.e.m.) of 0.24^0.01 pc, 0.22^0.01 pc, and
| |
| − | 0.33^0.02 pc for all cores, starless cores, and cores with EYSOs, respectively,
| |
| − | are marked with vertical bars in each panel.
| |
| − | 0 200 400 600 800 1000
| |
| − | 0
| |
| − | 50
| |
| − | 100
| |
| − | 150
| |
| − | 200
| |
| − | N=292
| |
| − | All Cores
| |
| − | 0
| |
| − | 50
| |
| − | 100
| |
| − | 150
| |
| − | 200
| |
| − | N=229
| |
| − | Starless Cores
| |
| − | 0
| |
| − | 50
| |
| − | 100
| |
| − | 150
| |
| − | 200
| |
| − | N=63
| |
| − | Cores with EYSOs
| |
| − | 0 2 4 6 8 10 12
| |
| − | 0
| |
| − | 50
| |
| − | 100
| |
| − | 150
| |
| − | N=308
| |
| − | Total
| |
| − | 0
| |
| − | 50
| |
| − | 100
| |
| − | 150
| |
| − | N=249
| |
| − | Starless Cores
| |
| − | 0
| |
| − | 50
| |
| − | 100
| |
| − | 150
| |
| − | N=58
| |
| − | Cores with EYSOs
| |
| − | 248 LEE & MYERS Vol. 123
| |
| − | FIG. 6.ÈDistance distribution of cores. The distributions of distances
| |
| − | of starless cores and cores with EYSO are not di†erent. The positions of
| |
| − | mean distance (mean^s.e.m.) of 231^8 pc, 227^8 pc, and 244^19 pc
| |
| − | for all cores, starless cores, and cores with EYSOs, respectively, are indicated
| |
| − | with vertical bars in each panel.
| |
| − | with similar distances. They are Taurus (Ungerechts &
| |
| − | Thaddeus 1987), Ophiuchus (de Geus, Bronfman, & Thaddeus
| |
| − | 1990), Lupus (Murphy, Cohen, & May 1986), Chamaeleon
| |
| − | II, III (Chen et al. 1997), and Vela (Vilas-Boas et al.
| |
| − | 1994). The boundaries of each areas were adopted from the
| |
| − | references listed above in parentheses.
| |
| − | 2.2.4. Implications of the Ratio of the Number of Cores with EY SOs
| |
| − | to the Number of Starless Cores
| |
| − | Our sample gives a ratio [N(cores with EYSOs)]/
| |
| − | [N(starless cores)] of about 0.31 (B94/306). This ratio is
| |
| − | important in constraining models of core formation, of
| |
| − | FIG. 7.ÈDistribution of the aspect ratio for all cores, starless cores, and
| |
| − | cores with EYSOs. The positions of the mean aspect ratio (mean^s.e.m.)
| |
| − | of 2.4^0.1, 2.4^0.1, and 2.2^0.2 for all cores, starless cores, and cores
| |
| − | with EYSOs, respectively, are indicated with vertical bars in each panel.
| |
| − | which ambipolar di†usion is the best known (Mestel &
| |
| − | Spitzer 1956). If every core undergoes ambipolar di†usion
| |
| − | (i.e., dense core formation), infall, and then protostellar
| |
| − | emission, the value of the ratio [N(cores with EYSOs)]/
| |
| − | [N(starless cores)] should be approximately [t(life of
| |
| − | protostar)]/[t(core formation)], assuming that the cores
| |
| − | have uncorrelated start times. The time t(life of protostar)
| |
| − | will correspond approximately to the duration of the class
| |
| − | 0]class I stages, based on our IRAS selection criteria
| |
| − | described in ° 2.1. This time interval has been observationally
| |
| − | determined to be about (1È5)]105 yr from the
| |
| − | relative numbers of embedded objects and T Tauri stars
| |
| − | FIG. 8.ÈDistributions in Galactic coordinates of (a) cores with EYSOs and (b) starless cores listed in Table 2
| |
| − | No. 1, 1999 OPTICALLY SELECTED CORES 249
| |
| − | (Myers et al. 1987; Wilking, Lada, & Young 1989; Kenyon
| |
| − | et al. 1990). The time t(core formation) should be the time
| |
| − | that the core is detectable at its typical observed density,
| |
| − | according to its formation model. The cores in our catalog
| |
| − | (most of which have been selected from Lynds classes 5 and
| |
| − | 6) are thought to have visual extinctions of 4.5È6 mag in
| |
| − | their centers (Cernicharo & Bachiller 1984). This means that
| |
| − | the mean number density in the center of our optically
| |
| − | selected cores is about (6È8)]103 cm~3, assuming a core
| |
| − | diameter of 0.24 pc from our statistics and the relationship
| |
| − | N(H cm~2 from Dickman (1978) where 2)B1]1021Av
| |
| − | N(H and are column density of and magnitude of 2) Av Hvisual extinction, respectively. Therefor2e the time that the
| |
| − | core has gas density (6È8)]103 cm~3 can be obtained from
| |
| − | ambipolar di†usion models. We Ðnd that di†erent models
| |
| − | give slightly di†erent time periods for gas to have such
| |
| − | density. The most detailed model ““B of Ciolek & Mous- UV ÏÏ
| |
| − | chovias (1995) gives about (5.5È6.7)]106 yr, the model by
| |
| − | Li (1998) about (3.5È4.1)]106 yr, and the model by Palla
| |
| − | & Galli (1997) about (8.7È13.4)]106 yr for a core with a
| |
| − | size of 0.24 pc and magnetic Ðeld strength of 30 kG. Thus
| |
| − | present ambipolar di†usion models seem to indicate that
| |
| − | detectable cores in our sample will be condensed within
| |
| − | about (3.5È13.4)]106 yr, after which the cores will
| |
| − | undergo dynamical, star-forming collapse. Thereby, the predicted
| |
| − | ratios of [t(life of protostar)]/[t(core formation)] is
| |
| − | [(1È5)]105]/[(3.5È13.4)]106]B0.007È0.14, which is
| |
| − | smaller than our empirical value (0.31) by a factor of about
| |
| − | 2È44. This discrepancy between model predictions and our
| |
| − | data is also seen for the Ðve star forming regions ; the
| |
| − | empirical ratios are 0.39 (B4/36) for Taurus, 0.46 (B9/41)
| |
| − | for Ophiuchus, 0.33 (B9/27) for Lupus, 0.23 (B3/13) for
| |
| − | Chamaeleon II and III, and 0.38 (B5/13) for Vela.
| |
| − | As a result, the timescale of ambipolar di†usion for core
| |
| − | formation in the present models seems to be too long, suggesting
| |
| − | that the models of ambipolar di†usion need to be
| |
| − | modiÐed or perhaps that faster mechanisms of core formation
| |
| − | should be also considered (cf. Tafalla et al. 1998). We
| |
| − | suggest that the typical lifetime of starless cores [Z(6È8)
| |
| − | ]103 cm~3] may be about 3 times longer than the duration
| |
| − | of the class 0 and class I phases, i.e., about (0.3È
| |
| − | 1.6]106) yr, which is shorter than the ambipolar model
| |
| − | prediction by a factor of 2È44. A similar conclusion was
| |
| − | reached by Jijina, Myers, & Adams (1998) based on statistics
| |
| − | of NH cores with and without associated stars. 3
| |
| − | 3. CONCLUSION
| |
| − | In this paper we present a new catalog of 406 dense cores
| |
| − | optically selected by using the STScI Digitized Sky Survey
| |
| − | (DSS). We have imaged areas of 0.52 or 1.0 deg2 around
| |
| − | already known numerous NH and C18O cores, every Lynds class 5 and 6 cloud (Lynds3 1962), and every southern
| |
| − | Hartley et al. (1986) class A cloud, to identify every local
| |
| − | minimum of intensity in each Ðeld and to select the darkest
| |
| − | and best resolved minima. For the identiÐed 406 sources, we
| |
| − | used the IRAS Point Source Catalog to determine which
| |
| − | have associated point sources and used the criteria for PMS
| |
| − | stars by Weintraub (1990) and the catalog of PMS stars by
| |
| − | Herbig & Bell (1988) to Ðnd possible PMS stars associated
| |
| − | with the cores. From these surveys, 306 starless cores with
| |
| − | neither an embedded YSO (EYSO) nor a preÈmainsequence
| |
| − | (PMS) star, 94 cores with EYSOs (one core has
| |
| − | both an EYSO and a PMS star), and six cores with only a
| |
| − | PMS star are found. This list of dense cores will be a useful
| |
| − | database for an extensive systematic study of dense cores for
| |
| − | a better understanding of the early stages of star formation.
| |
| − | Our fairly complete sample of most opaque cores gives
| |
| − | representative statistics of physical parameters of dense
| |
| − | cores. Most cores are found to have an apparent angular
| |
| − | size of 1@È4@ and a linear size of D0.1È0.3 pc, with an
| |
| − | average of 0.24 pc. Interestingly, the sizes (mean:
| |
| − | 0.33^0.03 pc) of the cores with EYSOs are usually larger
| |
| − | than those (mean: 0.21^0.01 pc) of the starless cores. The
| |
| − | mean aspect ratio of cores is 2.4^0.1, conÐrming that most
| |
| − | cores are more likely elongated than spherical.
| |
| − | The ratio of [N(cores with EYSOs)]/[N(starless cores)]
| |
| − | for our sample is about 0.31 (B94/306). This value is much
| |
| − | higher than expected from the relative time scales
| |
| − | ([t(life of protostar)]/[t(core formation)]B[(1È5)]105]/
| |
| − | [(3.5È13.4)]106]B0.007È0.14) of ambipolar di†usion of a
| |
| − | core [with gas densityZ(6È8)]103 cm~3] and the life of a
| |
| − | protostar. The statistics of our sample indicate that the
| |
| − | ambipolar di†usion timescale predicted by present models
| |
| − | for dense core formation may be too long. The typical lifetime
| |
| − | of starless cores is suggested to be about 3 times longer
| |
| − | than the duration of the class 0 and class I phases, i.e., about
| |
| − | (0.3È1.6)]106 yr, which is shorter than the ambipolar
| |
| − | model predictions by a factor of 2È44.
| |
| − | C. W. L acknowledges the Ðnancial support from the
| |
| − | 1996 Overseas Postdoctoral Support Program of Korea
| |
| − | Research Foundation. C. W. L also thanks the Harvard-
| |
| − | Smithsonian Center for Astrophysics for support while
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| − | working on this project. We would like to thank Lori Allen
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| − | and August Muench for their careful reading of our manuscript
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| − | and an anonymous referee for his useful comments.
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| − | This research was supported by NASA Origins of Solar
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| − | System Program, grant NAGW-3401.
| |
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| | This didn't format well. Please let me know if there is a better way to send papers | | This didn't format well. Please let me know if there is a better way to send papers |
| | Thanks | | Thanks |
| − | --[[User:Guastella|Guastella]] 20:48, 8 January 2008 (PST)
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| | Pete | | Pete |
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| | + | (--[[User:Rebull|Rebull]] 09:25, 9 January 2008 (PST) he's right, this didn't format well, so I replaced it with a link directly to ADS, from which you can get the complete article - there's no access restrictions on it, and if you go there, you can get the originally formatted PDF or the html. [http://adsabs.harvard.edu/abs/1999ApJS..123..233L ADS link to the Lee and Myers paper] |
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| | =LDN 1340= | | =LDN 1340= |
