Difference between revisions of "Lauren BRC 27"
| Line 10: | Line 10: | ||
'''Science background and Context:''' | '''Science background and Context:''' | ||
| − | '''BRC 27''' is a star forming region within the molecular cloud CMa R1, located at 07h03m39s -11d23m43s. This star forming region is believed to be a Radiation Driven Implosion (RDI) morphology, although what triggered the star formation is not certain at this time (Gregorio-Hetem et al, 2009). Previous works | + | '''BRC 27''' is a star forming region within the molecular cloud CMa R1, located at 07h03m39s -11d23m43s. This star forming region is believed to be a Radiation Driven Implosion (RDI) morphology, although what triggered the star formation is not certain at this time (Gregorio-Hetem et al, 2009). Previous works have identified stars using various techniques and different sources. Wiramihardja et al in 1986 used UBV photographic photometry, Sugitani et al in 1991 used IRAS sources. Soares and Bica in 2002 and 2003 determined a distance of 1.2 parsecs and an age of 1.5 Myr for the stars in BRC 27. The distance was consistent with the findings of Schevchenko in 1999. A wide field X-ray study of the CMa OB1/ R star forming region done by Gregorio- Hetem et al. (2009) was conducted to find low mass YSOs that may have been previously undetected. Chauhan et al in 2009 used BVIc photometry to compare the ages of stars inside and outside the rims. They suggest that there is evidence of an RDI mechanism. We note that Chauhan et al used archival IRAC, but not MIPS data, and moreover did not use the IRAC data as a primary mechanism to select YSO candidates; they used near-IR JHK colors to identify candidates. Johnson et al (2012)2012) and Rebull et al. (2012, in prep) used the mid-IR IRAC and MIPS colors to search for YSOs in a ~5'x5' footprint. They identified IR excesses around 21/33 previously-known YSO candidates and identified 19 entirely new YSO candidates. We will use WISE photometric data to survey a larger region (~10-15 arcmin diameter) around this relatively small ~5'x5' 4-band IRAC footprint from Spitzer to (a) look for IR excesses around previously-identified YSO candidates, and (b) look for new YSO candidates using the WISE bands. Because there are several prior shallow wide-field studies in this area, there are previously-identified YSOs here, and we also expect to find new YSO candidates. Since the WISE data survey will cover a larger region than the relatively small ~5'x5' 4-band IRAC footprint above, it will enable us to put the previous data into context by looking at the larger environment around BRC 27 itself -- e.g., the following questions: in the 4-band Spitzer area, the surface density of YSOs is ~1.6 per square arcminute (Johnson et al. 2012, Rebull et al. 2012); is there as high a surface density of YSOs outside of the IRAC footprint? How quickly does the YSO surface density fall off? Are there proportionally more Class IIs than Class Is farther from the center of the BRC? Because the Spitzer observations include 'flanking fields' of serendipitous data, when these data are available, we will use the Spitzer data in addition to the WISE data, enabling a better determination of the nature of the object, and setting up a "teachable moment" comparing the spatial resolution differences of the various observations, including those from the literature. |
'''Education and Outreach:''' | '''Education and Outreach:''' | ||
Revision as of 22:14, 2 March 2012
I found one article, published in July of 2011, that is not on the list. The title is 2MASS Wide field extinction map. I skimmed it, don't know if there's anything useful in it yet. I will go back through SIMBAD again to be sure that I have completely scoured that source for new papers.
[[1]]
--Novatne 09:48, 17 February 2012 (PST)
Lauren's first draft text
Science background and Context:
BRC 27 is a star forming region within the molecular cloud CMa R1, located at 07h03m39s -11d23m43s. This star forming region is believed to be a Radiation Driven Implosion (RDI) morphology, although what triggered the star formation is not certain at this time (Gregorio-Hetem et al, 2009). Previous works have identified stars using various techniques and different sources. Wiramihardja et al in 1986 used UBV photographic photometry, Sugitani et al in 1991 used IRAS sources. Soares and Bica in 2002 and 2003 determined a distance of 1.2 parsecs and an age of 1.5 Myr for the stars in BRC 27. The distance was consistent with the findings of Schevchenko in 1999. A wide field X-ray study of the CMa OB1/ R star forming region done by Gregorio- Hetem et al. (2009) was conducted to find low mass YSOs that may have been previously undetected. Chauhan et al in 2009 used BVIc photometry to compare the ages of stars inside and outside the rims. They suggest that there is evidence of an RDI mechanism. We note that Chauhan et al used archival IRAC, but not MIPS data, and moreover did not use the IRAC data as a primary mechanism to select YSO candidates; they used near-IR JHK colors to identify candidates. Johnson et al (2012)2012) and Rebull et al. (2012, in prep) used the mid-IR IRAC and MIPS colors to search for YSOs in a ~5'x5' footprint. They identified IR excesses around 21/33 previously-known YSO candidates and identified 19 entirely new YSO candidates. We will use WISE photometric data to survey a larger region (~10-15 arcmin diameter) around this relatively small ~5'x5' 4-band IRAC footprint from Spitzer to (a) look for IR excesses around previously-identified YSO candidates, and (b) look for new YSO candidates using the WISE bands. Because there are several prior shallow wide-field studies in this area, there are previously-identified YSOs here, and we also expect to find new YSO candidates. Since the WISE data survey will cover a larger region than the relatively small ~5'x5' 4-band IRAC footprint above, it will enable us to put the previous data into context by looking at the larger environment around BRC 27 itself -- e.g., the following questions: in the 4-band Spitzer area, the surface density of YSOs is ~1.6 per square arcminute (Johnson et al. 2012, Rebull et al. 2012); is there as high a surface density of YSOs outside of the IRAC footprint? How quickly does the YSO surface density fall off? Are there proportionally more Class IIs than Class Is farther from the center of the BRC? Because the Spitzer observations include 'flanking fields' of serendipitous data, when these data are available, we will use the Spitzer data in addition to the WISE data, enabling a better determination of the nature of the object, and setting up a "teachable moment" comparing the spatial resolution differences of the various observations, including those from the literature.
Education and Outreach:
Team Reedley College
A small group of college freshman and sophomores will meet weekly. For the first few weeks, the students will be instructed on the basics of star formation and stellar evolution. Once the students understand the basics, they will begin reading the appropriate journals and conduct web research for discussion. Once the data processing instruction has been completed, the students will work together and separately on the data analysis portion of the project.
The weekly meetings will introduce the students to: • Star formation mechanism and stellar life cycle • Spectral analysis • Black body curves • Photometry
In the fall of 2012, the weekly meetings will be include to the processing of data. --Novatne 14:51, 18 February 2012 (PST)
Luisa's tweaking
Science background and Context:
BRC 27 is a star forming region within the molecular cloud CMa R1, located at 07h03m39s -11d23m43s. This star forming region is believed to be triggered star formation, specifically a Radiation Driven Implosion (RDI) morphology (see, e.g., Sugitani et al. 1991), although exactly what object(s) triggered the star formation is not certain at this time (Gregorio-Hetem et al, 2009). Several previous studies have identified stars using various techniques and different sources. Wiramihardja et al. (1986) used UBV photographic photometry in this larger area. Sugitani et al. (1991) -- the origin of the BRC nomenclature -- used IRAS sources combined with Palomar Observatory Sky Survey plates to identify bright rimmed clouds likely to be sites of triggered star formation. Soares and Bica (2002, 2003) determined a distance of ~1.2 parsecs and an age of ~1.5 Myr for the stars in BRC 27 using an early version of the Two-Micron All-Sky Survey (2MASS) catalog. This distance is consistent with the findings of Shevchenko et al. (1999), who used photoelectric photometry(!) and objective prism spectroscopy in this region to identify YSOs. A wide field X-ray study of the CMa OB1/ R! star forming region done by Gregorio-Hetem et al. (2009) identified several low mass YSOs using X-rays. IF YOU ARE GOING TO CITE SPECIFIC NUMBERS FOR OBJECTS FOUND VIA X-RAYS, YOU NEED TO SPECIFY NUMBER OF OBJECTS FOUND IN THE OTHER STUDIES. A TABLE OR PLOT IS MAYBE IN ORDER. HOWEVER, THIS MAY BE A SIGNIFICANT AMOUNT OF WORK -- (A) |THIS IS LAST YEAR'S THRASHING, AND (B) I ONLY HAVE OBJECTS IN MY CATALOG CLOSE TO Z CMa BECAUSE THAT'S ALL WE CARED ABOUT LAST YEAR. YOUR CALL AS TO WHETHER OR NOT TO KEEP THESE NEXT 2 SENTENCES. Their work found approximately 40 members near Z Ma and approximately 60 members near GU CMa. Both of these regions are close to BRC 27. STRIKE THIS NEXT SENTENCE, BECAUSE MORGAN ET AL HAS SUCH A LOW SPATIAL RESOLUTION THAT THEY ARE NOT SEEING THE INDIVIDUAL SOURCES THAT WE ARE SEEING. Morgan et al. used the Submillimeter Common User Bolometer Array (SCUBA) in 2008 to survey 44 bright-rimmed clouds to identify a dense core in BRC 27. Chauhan et al. (2009) used BVIc photometry, as well as 2MASS JHK and Spitzer IRAC data, to identify stars and compare the ages of stars inside and outside the rims. They suggest that there is evidence of an RDI mechanism. We note that Chauhan et al. (2009) used archival IRAC, but not MIPS data, and moreover did not use the IRAC data as a primary mechanism to select YSO candidates; they used near-IR JHK colors to identify candidates. Johnson et al. (2012) and Rebull et al. (2012, in prep) used the mid-IR IRAC and MIPS colors to search for YSOs in a ~5'x5' footprint. They identified IR excesses around 21/33 previously-known YSO candidates and identified 19 entirely new YSO candidates. We will use WISE photometric data to survey a larger region (~10-15 arcmin diameter) around this relatively small ~5'x5' 4-band IRAC footprint from Spitzer to (a) look for IR excesses around previously-identified YSO candidates, and (b) look for new YSO candidates using the WISE bands. Because there are several prior shallow wide-field studies in this area, there are previously-identified YSOs here, and we also expect to find new YSO candidates. Since the WISE data survey will cover a larger region than the relatively small ~5'x5' 4-band IRAC footprint above, it will enable us to put the previous data into context by looking at the larger environment around BRC 27 itself -- e.g., the following questions: in the 4-band Spitzer area, the surface density of YSOs is ~1.6 per square arcminute (Johnson et al. 2012, Rebull et al. 2012); is there as high a surface density of YSOs outside of the IRAC footprint? How quickly does the YSO surface density fall off? Are there proportionally more Class IIs than Class Is farther from the center of the BRC?
SOME OF THE CONCEPTS I INCLUDED IN THE ABOVE ARE MORE GENERIC, AND APPLY TO MORE THAN JUST BRC 27, THOUGH THE SURFACE DENSITY I CITE IS DEFINITELY CUSTOMIZED TO BRC 27. THIS NEXT CONCEPT IS ALSO GENERIC: Because the Spitzer observations include 'flanking fields' of serendipitous data, when these data are available, we will use the Spitzer data in addition to the WISE data, enabling a better determination of the nature of the object, and setting up a "teachable moment" comparing the spatial resolution differences of the various observations, including those from the literature.
Education and Outreach:
Team Reedley College
A small group of college freshman and sophomores will meet weekly. For the first few weeks, the students will be instructed on the basics of star formation and stellar evolution. Once the students understand the basics, they will begin reading the appropriate journals and conduct web research for discussion. Once the data processing instruction has been completed, the students will work together and separately on the data analysis portion of the project.
The weekly meetings will introduce the students to: • Star formation mechanism and stellar life cycle • Spectral analysis • Black body curves • Photometry
In the fall of 2012, the weekly meetings will be include to the processing of data. --Novatne 14:51, 18 February 2012 (PST)
