2011/06/03 by Chiaki Shirono, Yoichi Itoh, Yumiko Oasa
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics and Star Formation Studies #Brown dwarf #Infrared #Molecular cloud #Serpens #Spectral line #Stellar classification #Stellar, planetary, and galactic studies #Young stellar object #astro-ph.SR
paper · pdf · doi:10.1093/pasj/63.5.1071
11 pages, 7 figures. P.A.S.J. accepted
arxiv created 2011/06/03 · openalex publication_date 2011/10/25 · arxiv updated 2015/05/28 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Abstract We conducted an infrared search for faint companions around 351 young stellar objects in the ρ Ophiuchi molecular cloud and the Serpens molecular cloud. Nine objects in the Spitzer/IRAC archival images were identified as being young stellar companion candidates. They showed an intrinsic infrared excess; one object was extremely red both in the [3.6]-[4.5] color and in the [4.5]-[5.8] color, and two objects were red in the [4.5]-[5.8] color. They were as faint as 15 mag in the [3.6] band. Follow-up K-band spectroscopy revealed that the three objects had deep water absorption bands, indicative of low effective temperatures. By comparing their spectra and infrared spectral energy distributions with synthesized spectra of low-temperature objects, we derived the effective temperatures and continuum excesses for these objects. It is very likely that one is a low-mass stellar companion, and two others are young brown dwarf companions associated with young stellar objects.