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| EPoS Contribution |
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Characteristics of Young Stellar Objects
in SFO 38
Rumpa Choudhury Indian Institute of Astrophysics, Bangalore, India | |
| We have investigated the young stellar population in/around SFO 38, one of the massive globules located in the northern part of galactic HII region IC 1396, using the Spitzer IRAC and MIPS observations (3.6 to 24 micron) and followed up with ground based optical photometric and spectroscopic observations. Based on the IRAC and MIPS colors we identify ~ 50 Young Stellar Objects (YSOs) (Classes 0/I/II)and 13 probable Pre Main Sequence candidates. We derive the spectral types (mostly K- and M-type stars), effective temperatures and individual extinction for relatively bright and optically visible Class II objects. Most of the Class II objects show variable H-alpha emission as well as optical and near-IR photometric variability which also confirm their "youth". Using the optical photometry and theoretical isochrones, we estimate the spread in stellar ages from 1 to 10 Myrs with a median age of 3 Myr and a mass distribution of .3-2.2 Msun with a median value around 0.5 Msun. Using the width of H-alpha emission line measured at 10% peak intensity, we derive the mass accretion rates of individual objects which ranges from 10^{-10} to 10^{-8} Msun/yr. We find significant variation in H-alpha emission and accretion rate in one transitional disk object. From the continuum-subtracted H-alpha line image, we find that the H-alpha emission of the globule is not spatially symmetric with respect to the O type ionising star HD 206267 and the interstellar extinction towards the globule is also anomalous. Based on the positions of the YSOs on the H-alpha line image, we find a clear signature of evolution of YSOs from the rim to the dense core of the cloud with most of the Class II objects located at the bright rim. Further, enhanced concentration of YSOs along the axis of the globule as seen in our study is consistent with the Radiation Driven Implosion model of triggered star formation. | |
| Collaborators: B. Mookerjea, TIFR Mumbai, India H. C. Bhatt, IIA Bangalore, India |
Suggested Session:
Early Phases of Disks |