Difference between revisions of "Talk:CG4 Spring work"

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For Apr 14:
+
=For Apr 14: KEVIN -- Reipurth and Pettersson 1993 =
 +
http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?1993A%26A...267..439R&data_type=PDF_HIGH&whole_paper=YES&type=PRINTER&filetype=.pdf
  
    * KEVIN -- Reipurth and Pettersson 1993 
+
==''Main Point''==
    http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?1993A%26A...267..439R&data_type=PDF_HIGH&whole_paper=YES&type=PRINTER&filetype=.pdf
+
Found 8 new YSOs in Gum Nebula (near CG4 and Sa101 and CG13) using IR photometry, UBV photometry and spectroscopy.
  
*''Main Point''
+
==''High Level Summary''==
 +
Surveyed 5 fields with 15 cometary globules
 +
Found 8 new YSOs
 +
Confirmed one previous YSO
  
*''High Level Summary''
+
Equipment Used
  
*''Most Interesting''
+
  Ha spectroscopy                      CTIO 60/90cm Curtis Schmidt telescope with 6deg prism    1-2hrs
 +
  JHK IR photometry (sort of like us)  ESO 1m        J-H and H-K
 +
  UBV photometry (like us)            ESO 1m
 +
  Point source spectroscopy            ESO 1.52m and 3.6m        3700A to 7000A                    10-40 min
  
*''I agree with this''
+
found there are different ages (spectra and movement away from globule)
 +
Found late-type premain sequence stars
  
*''I disagree with this''
+
Identified spectral type using spectra
 +
ruled out forground/background with spectra and
  
*''Why we should care''
+
==''Most Interesting''==
 +
Introduction:
 +
Good description of cometary nebulae
 +
Good rundown of CG formation theory
 +
1.  OB starformed nearby and the UV radiation scrunched and eroded nearby nebula (some evidence in this paper for this method)
 +
2.  or SN went off nearby and shockwave scrunched and eroded nearby nebula
 +
CG4 might have been evaporating for 1,000,000years
  
  
 +
CG4 might have been a shade for Sa101 to hide behind.  Until the
 +
CG4 evaporation may have started >1,000,000 years ago.
 +
In faint background stars they found stars becoming more prominent as they used longer wavelength filters (good for us)
 +
 +
 +
Spectral classes
 +
M3 to K7
 +
M2, M3-4, K7-M0, K7, K2-5, K5, M1-2, K2
 +
 
 +
==''Not sure about this''==
 +
Questions and Kevin trying to dodge the answers
  
For Apr 21:
+
TiO and MgH
    *VIVIAN -- Kim et al 2003 http://adsabs.harvard.edu/abs/2003csss...12..799K
+
using the width and
    Full Paper link click here. [http://origins.colorado.edu/cs12/proceedings/poster/kimxx.pdf]
 
  
*''Main Point''
+
Ha
  
*''High Level Summary''
+
width of line (spinning?)
 +
 +
Balmer series
 +
forbidden [OI] linesat 6300 and 6363A
 +
prominent absorption at 5577A
 +
absorbtion trough at 6200A deeper
 +
       
  
*''Most Interesting''
+
==''I agree with this''==
  
*''I agree with this''
+
found eight new YSOs in the area
 +
confirmed one previous YSO
 +
found there are different ages (spectra and movement away from globule)
 +
Found late-type premain sequence stars
  
*''I disagree with this''
+
==''I disagree with this''==
 +
found there are different ages (spectra and movement away from globule)
 +
probably continuous (from 8 stars?)
  
*''Why we should care''
+
==''Why we should care''==
  
 +
found seven new YSOs in the area
 +
confirmed one previous YSO
 +
Used some of the same techniques we will
 +
Found YSOs and confirmed previous ones
 +
Found faint background stars getting more prominent in longer wavelength filters
 +
Not all CG had star formation but CG4 was one that had some nearby
  
For Apr 28:
 
    *CHELEN -- Kim 2005
 
    http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?2003ASPC..287..275K&data_type=PDF_HIGH&whole_paper=YES&type=PRINTER&filetype=.pdf
 
  
*''Main Point''
+
=For Apr 21: VIVIAN -- Kim et al 2003=
 +
http://adsabs.harvard.edu/abs/2003csss...12..799K
 +
Full Paper link click here. [http://origins.colorado.edu/cs12/proceedings/poster/kimxx.pdf]
  
*''High Level Summary''
+
==''Main Point''==
 +
High mass stars can terminate low mass star formation (LMSF) or they can trigger it. 
  
*''Most Interesting''
+
==''High Level Summary''==
 +
Pressure induced by winds and radiation from high mass stars and by radiation can sweep away low density clouds surrounding low mass stars, but can also collapse the surrounding clouds and start low mass star formation (LMSF) in the cores of these remnant clouds. Cometary globules in places like the Gum Nebula are perfect places to study this triggered LMSF. CGs are evaporating molecular cloud cores with head-tail geometry.  The head points towards the HMS source of the winds and radiation causing the evaporation.
  
*''I agree with this''
+
==''What they did''==
 +
They analyzed X-Ray ROSAT/HRI data, Optical Data for photometry from CTIO/0.9m, and Near-IR using JHK images from the CIRIM detector on the CTIO/1.5m telescope.
  
*''I disagree with this''
+
==''Most Interesting''==
 +
Section 3.2 addresses our CG4.  They did optical photometry.
  
*''Why we should care''
+
==''I agree with this''==
  
 +
==''I disagree with this''==
 +
Did they get different object data on different telescopes of the same or different regions.  I'll explain better on the phone.
  
For May 5:
+
==''Why we should care''==
    *CAROLYN -- Choudhury and Bhatt 2008 
+
Summary states that "There are indeed candidate PMS stars in .... CG4 ..... They think there are a few PMS stars in CG4; that there are none around the eroded head of CG4 and suggest that there is an age gradient from the head to the tail. The suggested explanation is that the LMSF in the region may have been gradual and under the influence of the high mass stars in Vela OB2.  
    http://arxiv.org/PS_cache/arxiv/pdf/0811/0811.4389v1.pdf 
 
    the ADS entry is http://adsabs.harvard.edu/abs/2009MNRAS.393..959C
 
    and I downloaded the real journal article for you (easier to read!) here: [[media:choud.pdf]]
 
  
*''Main Point''
 
  
*''High Level Summary''
+
=For Apr 28: CHELEN -- Kim 2005 =
 +
http://adsabs.harvard.edu/abs/2005AJ....129.1564K
  
*''Most Interesting''
+
==''Main Point''==
  
*''I agree with this''
+
==''High Level Summary''==
  
*''I disagree with this''
+
==''Most Interesting''==
  
*''Why we should care''
+
==''I agree with this''==
 +
 
 +
==''I disagree with this''==
 +
 
 +
==''Why we should care''==
 +
 
 +
 
 +
=For May 5: CAROLYN -- Choudhury and Bhatt 2008  =
 +
http://arxiv.org/PS_cache/arxiv/pdf/0811/0811.4389v1.pdf 
 +
the ADS entry is http://adsabs.harvard.edu/abs/2009MNRAS.393..959C  and I downloaded the real journal article for you (easier to read!) here: [[media:choud.pdf]]
 +
 
 +
==''Main Point''==
 +
 
 +
==''High Level Summary''==
 +
 
 +
==''Most Interesting''==
 +
 
 +
==''I agree with this''==
 +
 
 +
==''I disagree with this''==
 +
 
 +
==''Why we should care''==

Latest revision as of 22:57, 21 April 2010

For Apr 14: KEVIN -- Reipurth and Pettersson 1993

http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?1993A%26A...267..439R&data_type=PDF_HIGH&whole_paper=YES&type=PRINTER&filetype=.pdf

Main Point

Found 8 new YSOs in Gum Nebula (near CG4 and Sa101 and CG13) using IR photometry, UBV photometry and spectroscopy.

High Level Summary

Surveyed 5 fields with 15 cometary globules Found 8 new YSOs Confirmed one previous YSO

Equipment Used

 Ha spectroscopy                      CTIO 60/90cm Curtis Schmidt telescope with 6deg prism    1-2hrs
 JHK IR photometry (sort of like us)  ESO 1m        J-H and H-K
 UBV photometry (like us)             ESO 1m
 Point source spectroscopy            ESO 1.52m and 3.6m        3700A to 7000A                    10-40 min

found there are different ages (spectra and movement away from globule) Found late-type premain sequence stars

Identified spectral type using spectra ruled out forground/background with spectra and

Most Interesting

Introduction: Good description of cometary nebulae Good rundown of CG formation theory

1.  OB starformed nearby and the UV radiation scrunched and eroded nearby nebula (some evidence in this paper for this method)
2.  or SN went off nearby and shockwave scrunched and eroded nearby nebula

CG4 might have been evaporating for 1,000,000years


CG4 might have been a shade for Sa101 to hide behind. Until the CG4 evaporation may have started >1,000,000 years ago. In faint background stars they found stars becoming more prominent as they used longer wavelength filters (good for us)


Spectral classes M3 to K7 M2, M3-4, K7-M0, K7, K2-5, K5, M1-2, K2

Not sure about this

Questions and Kevin trying to dodge the answers

TiO and MgH using the width and

Ha

width of line (spinning?)

Balmer series forbidden [OI] linesat 6300 and 6363A prominent absorption at 5577A absorbtion trough at 6200A deeper


I agree with this

found eight new YSOs in the area confirmed one previous YSO found there are different ages (spectra and movement away from globule) Found late-type premain sequence stars

I disagree with this

found there are different ages (spectra and movement away from globule) probably continuous (from 8 stars?)

Why we should care

found seven new YSOs in the area confirmed one previous YSO Used some of the same techniques we will Found YSOs and confirmed previous ones Found faint background stars getting more prominent in longer wavelength filters Not all CG had star formation but CG4 was one that had some nearby


For Apr 21: VIVIAN -- Kim et al 2003

http://adsabs.harvard.edu/abs/2003csss...12..799K Full Paper link click here. [1]

Main Point

High mass stars can terminate low mass star formation (LMSF) or they can trigger it.

High Level Summary

Pressure induced by winds and radiation from high mass stars and by radiation can sweep away low density clouds surrounding low mass stars, but can also collapse the surrounding clouds and start low mass star formation (LMSF) in the cores of these remnant clouds. Cometary globules in places like the Gum Nebula are perfect places to study this triggered LMSF. CGs are evaporating molecular cloud cores with head-tail geometry. The head points towards the HMS source of the winds and radiation causing the evaporation.

What they did

They analyzed X-Ray ROSAT/HRI data, Optical Data for photometry from CTIO/0.9m, and Near-IR using JHK images from the CIRIM detector on the CTIO/1.5m telescope.

Most Interesting

Section 3.2 addresses our CG4. They did optical photometry.

I agree with this

I disagree with this

Did they get different object data on different telescopes of the same or different regions. I'll explain better on the phone.

Why we should care

Summary states that "There are indeed candidate PMS stars in .... CG4 ..... They think there are a few PMS stars in CG4; that there are none around the eroded head of CG4 and suggest that there is an age gradient from the head to the tail. The suggested explanation is that the LMSF in the region may have been gradual and under the influence of the high mass stars in Vela OB2.


For Apr 28: CHELEN -- Kim 2005

http://adsabs.harvard.edu/abs/2005AJ....129.1564K

Main Point

High Level Summary

Most Interesting

I agree with this

I disagree with this

Why we should care

For May 5: CAROLYN -- Choudhury and Bhatt 2008

http://arxiv.org/PS_cache/arxiv/pdf/0811/0811.4389v1.pdf the ADS entry is http://adsabs.harvard.edu/abs/2009MNRAS.393..959C and I downloaded the real journal article for you (easier to read!) here: media:choud.pdf

Main Point

High Level Summary

Most Interesting

I agree with this

I disagree with this

Why we should care