research
A 1.3 mm SMA Survey of 29 Variable Young Stellar Objects
- Publication date
- Publisher
- 'EDP Sciences'
Abstract
Young stellar objects (YSOs) may undergo periods of active accretion (outbursts), during which the protostellar accretion rate is temporarily enhanced by a few orders of magnitude. Whether or not these accretion outburst YSOs possess similar dust/gas reservoirs to each other, and whether or not their dust/gas reservoirs are similar as quiescent YSOs, are issues not yet clarified. The aim of this work is to characterize the millimeter thermal dust emission properties of a statistically significant sample of long and short duration accretion outburst YSOs (i.e., FUors and EXors) and the spectroscopically identified candidates of accretion outbursting YSOs (i.e., FUor-like objects). We have carried out extensive Submillimeter Array (SMA) observations mostly at ∼225 GHz (1.33 mm) and ∼272 GHz (1.10 mm), from 2008 to 2017. We covered accretion outburst YSOs located at 3-σ significance. Detected sources except for the two cases of V883 Ori and NGC 2071 MM3 were observed with ∼1" angular resolution. Overall our observed targets show a systematically higher millimeter luminosity distribution than those of the M∗>0.3 M⊙ Class II YSOs in the nearby (≲400 pc) low-mass star-forming molecular clouds (e.g., Taurus, Lupus, Upp Scorpio, and Chameleon I). In addition, at 1 mm our observed confirmed binaries or triple-system sources are systematically fainter than the rest of the sources even though their 1 mm fluxes are broadly distributed. We may have detected ∼30-60\% millimeter flux variability from V2494 Cyg and V2495 Cyg, from the observations separated by ∼1 year