TY - CONF
T1 - Disk Evolution of Young Stellar Objects in Lynds 1641
AU - Kim, J. S.
AU - Fang, M.
AU - Sicilia-Aguilar, A.
AU - van Boekel, R.
AU - Henning, T.
PY - 2014/8/1
Y1 - 2014/8/1
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%.
M3 - Paper
SP - 41
ER -