Spectroscopic Survey of Hα Emission Line Stars Associated with Bright Rimmed Clouds
arXiv:2006.00219 · doi:10.4236/ijaa.2019.92012
Abstract
The results of a spectroscopic survey of H alpha emission line stars associated with fourteen bright rimmed clouds are presented. Slit-less optical spectroscopy was carried out with the Inter University Centre for Astronomy and Astrophysics (IUCAA) 2m telescope and IUCAA Faint Object Spectrograph and Camera (IFOSC). H alpha emission line was detected from 173 objects. Among them 85 objects have a strong H alpha emission line with its equivalent width larger than 10 A. Those are classical T Tauri stars. 52 objects have a weak H alpha emission line with its equivalent width less than 10 A and do not show intrinsic near-infrared excess. Those are weak-line T Tauri stars. On the other hand, 36 objects have a weak H alpha emission line (<10 A), although they show intrinsic near-infrared excess. Such objects are not common in low-mass star forming regions. Those are misfits of the general concept on formation process of a low-mass star, in which it evolves from a classical T Tauri star to a weak-line T Tauri star. Those might be weak-line T Tauri stars with a flared disk in which gas is heated by ultraviolet radiation from a nearby early-type star. Alternatively, we propose pre-transitional disk objects as their evolutional stage.
References in corpus (7)
- Complex organic molecules in protoplanetary disks
- A Chandra Study of the Rosette Star-Forming Complex. I. The Stellar Population and Structure of the Young Open Cluster NGC 2244
- The Gaia-ESO Survey: Chromospheric Emission, Accretion Properties, and Rotation in Velorum and Chamaeleon I
- The evolution of stars in the Taurus-Auriga T association
- Sequential star formation in a cometary globule (BRC37) of IC1396
- Near-IR Imaging Polarimetry toward a Bright-Rimmed Cloud: Magnetic Field in SFO 74
- Disk Dissipation Timescale of Pre-main Sequence Stars in Taurus