2019/01/01 by K. Hosoya, Kensuke Hosoya, Yoichi Itoh +4 · 5 citations
Physics and Astronomy · #Astro and Planetary Science #Astronomy #Astrophysics #Astrophysics and Star Formation Studies #Emission spectrum #Equivalent width #H-alpha #Infrared #Line (geometry) #Physics #Spectral line #Star (game theory) #Stars #Stellar, planetary, and galactic studies #T Tauri star #Telescope #astro-ph.GA #astro-ph.SR
paper · pdf · doi:10.4236/ijaa.2019.92012
published in International Journal of Astronomy and Astrophysics 09(02), 154-171 (Scientific Research Publishing)
openalex publication_date 2019/01/01 · openalex created_date 2019/06/27 · arxiv created 2020/05/30 · arxiv updated 2020/06/02 · openalex updated_date 2026/08/05
The results of a spectroscopic survey of Hα 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) 2 m telescope and IUCAA Faint Object Spectrograph and Camera (IFOSC). Hα emission line was detected from 173 objects. Among them 85 objects have a strong Hα emission line with its equivalent width larger than 10 ?. Those are classical T Tauri stars. 52 objects have a weak Hα emission line with its equivalent width less than 10 ? and do not show intrinsic near-infrared excess. Those are weak-line T Tauri stars. On the other hand, 36 objects have a weak Hα emission line (?), 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.