2004/07/20 by D. Barrado, David Barrado y Navascues, Ray Jayawardhana · 2 citations
Physics and Astronomy · #Astro and Planetary Science #Astrophysics and Star Formation Studies #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1086/424560
published as Astrophys.J. 615 (2004) 840-849 · Astrophysical Journal, accepted June 19, 2004
arxiv created 2004/07/20 · openalex publication_date 2004/11/10 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/31
We have obtained low- and medium-resolution optical spectra of 20 candidate young low-mass stars and brown dwarfs in the nearby Chamaeleon II dark cloud using the Magellan Baade telescope. We analyze these data in conjunction with near-infrared photometry from the Two Micron All Sky Survey. We find that one target, [VCE2001] C41, exhibits broad Hα emission as well as a variety of forbidden emission lines. These signatures are usually associated with accretion and outflow in young stars and brown dwarfs. Our spectra of C41 also reveal Li I in absorption and allow us to derive a spectral type of M5.5 for it. Therefore, we propose that C41 is a classical T Tauri object near the substellar boundary. Thirteen other targets in our sample have continuum spectra without intrinsic absorption or emission features and are difficult to characterize. They may be background giants or foreground field stars not associated with the cloud or embedded protostars and need further investigation. The six remaining candidates, with moderate reddening, are likely to be older field dwarfs, given their spectral types, lack of lithium, and Hα emission.