Disk Evolution of Young Stellar Objects in Lynds 1641

TY - CHAP

T1 - Disk Evolution of Young Stellar Objects in Lynds 1641

AU - Kim, J. S.

AU - Fang, M.

AU - Van Boekel, Roy

AU - Sicilia-Aguilar, Aurora

AU - Henning, Th.

N1 - Paper

PY - 2014/8

Y1 - 2014/8

N2 - 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%.

AB - 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%.

UR - http://www.aspbooks.org/a/volumes/table_of_contents/?book_id=545

U2 - http://adsabs.harvard.edu/abs/2014ASPC..482...41K

DO - http://adsabs.harvard.edu/abs/2014ASPC..482...41K

M3 - Chapter

SN - 9781583818480

VL - 482

T3 - ASP Conference Series

SP - 41

BT - Tenth Pacific Rim Conference on Stellar Astrophysics

A2 - Lee, Hee-Won

A2 - Woon Kang, Young

A2 - Leung, Kim-Ching

CY - United States

T2 - Tenth Pacific Rim Conference on Stellar Astrophysics

Y2 - 27 May 2014 through 31 May 2014

ER -