AAS 201st Meeting, January, 2003
Session 136. Star Formation Young Stars
Oral, Thursday, January 9, 2003, 2:00-3:30pm, 606-607

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[136.05D] Low Mass Star Formation in the Gum Nebula: I. CG30/31/38

J. Serena Kim (SUNY Stony Brook / Steward Observatory), F. M. Walter (SUNY Stony Brook), S. J. Wolk (CfA)

We present photometric and spectroscopic results for the low mass pre-main sequence (PMS) stars in the cometary globule (CG) 30/31/38 complex. We obtained multi-object high resolution spectra for the targets selected from our multi-wavelength photometry (X-ray, optical, and near IR) using the CTIO-4m/HYDRA in echelle mode. We identified 11 PMS stars brighter than V=16.5 with age < 5 Myr at a distance of approximately 200 pc. The spatial distribution of PMS stars, CG clouds, and ionizing sources (O stars and supernova remnants) suggests a triggered origin of star formation occurred in this star forming region. The Li abundance of PMS stars confirms the youth of these PMS stars supporting our previous photometric results. Most of the these stars show weak H\alpha emission with W\lambda(H{\alpha}) < 10Å. Only 1 out of the 11 PMS stars shows moderate near IR excess, which indicate short survival time of circumstellar disks (t < 5Myr) in this star forming environment. The mass function, including other PMS candidates appear in the same PMS locus, peaks at approximately M2-M3 type stars (M=0.3-0.4M\odot). The sharp cut-off of PMS population at V < 18 (M<0.15M\odot) may imply that the ionizing sources responsible for the triggering the star formation could also halt low mass star formation by evaporating clouds.

The author(s) of this abstract have provided an email address for comments about the abstract: serena@as.arizona.edu

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Bulletin of the American Astronomical Society, 34, #4
© 2002. The American Astronomical Soceity.