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Paper: |
Disk Evolution of Young Stellar Objects in Lynds 1641 |
Volume: |
482, 10th Pacific Rim Conference on Stellar Astrophysics |
Page: |
41 |
Authors: |
Kim, J. S.; Fang, M.; Sicilia-Aguilar, A.; van Boekel, R.; Henning, T. |
Abstract: |
We study circumstellar disk evolution in young star forming regions under various environments, and here we present our recent results in Lynds 1641 located at Orion A cloud. Planet formation is one of the mechanisms for disk dispersal, however, other possible mechanisms include photoevaporation, grain growth, magneto-rotational instability, and close companion. In order to study disk dispersal mechanisms, we carried out multi-wavelength imaging and optical spectroscopic studies of young stellar objects (YSOs) in Lynds1641, and identified ∼1390 YSOs. We followed up with optical spectroscopy using MMT/Hectospec and Hectochelle for low - high resolution spectroscopy. We summarize our recent findings from both imaging and spectroscopic analysis (Fang, Kim, van Boekel et al. 2013): we identifed 143 Class I sources, 131 Flat spectrum sources, 533 Class II sources, and 507 class III sources. Among the confirme YSOs, 46 of them are transition disks in L1641. We find that: (i) both clustered and isolated mode of star formation are seen in L1641; (ii) there are age differences in median age for different disk morphologies (∼1.1Myr for optically thick disks, ∼1.5Myr for trandision disks, and ∼1.8Myr for diskless stars); (iii) ∼80% of optically thick disks show accretion, while ∼40–45% of transition disks show accretion; (iv) amplitude of accretion rate and variability for both optically thick disks and transition disks are similar; (v) accretion variability can account for about 0.6 dex in accretion rate vs. mass relation; and (vi) disk frequency of the L1641 region is about 50%. |
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