Abstract
Aims: This study aims to determine the impact of stellar binary
companions on the lifetime and evolution of circumstellar disks in the
Chamaeleon I (Cha I) star-forming region by measuring the frequency and
strength of accretion and circumstellar dust signatures around the
individual components of T Tauri binary stars. Methods: We used
high-angular resolution adaptive optics JHKsL' -band
photometry and 1.5-2.5 μm spectroscopy of 19 visual binary and 7
triple stars in Cha I - including one newly discovered tertiary
component - with separations between ~25 and ~1000 AU. The data allowed
us to infer stellar component masses and ages and, from the detection of
near-infrared excess emission and the strength of Brackett-γ
emission, the presence of ongoing accretion and hot circumstellar dust
of the individual stellar components of each binary. Results: Of
all the stellar components in close binaries with separations of 25-100
AU, 10+15-5% show signs of accretion. This is less
than half of the accretor fraction found in wider binaries, which itself
appears significantly reduced (~44%) compared with previous measurements
of single stars in Cha I. Hot dust was found around
50+30-15% of the target components, a value that
is indistinguishable from that of Cha I single stars. Only the closest
binaries (
| Original language | English |
|---|---|
| Journal | Astronomy & Astrophysics |
| Volume | 554 |
| DOIs | |
| Publication status | Published - 1 Jun 2013 |
Keywords
- stars: late-type
- stars: formation
- circumstellar matter
- binaries: visual