Large dust particles in disks around T Tauri stars

被引:193
作者
Rodmann, J
Henning, T
Chandler, CJ
Mundy, LG
Wilner, DJ
机构
[1] Max Planck Inst Astron, D-69117 Heidelberg, Germany
[2] Natl Radio Astron Observ, Socorro, NM 87801 USA
[3] Univ Maryland, Dept Astron, College Pk, MD 20742 USA
[4] Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA
关键词
stars : pre-main sequence; stars : planetary systems : protoplanetary disks; planetary systems : formation;
D O I
10.1051/0004-6361:20054038
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
We present 7-mm continuum observations of 14 low-mass pre-main-sequence stars in the Taurus-Auriga star-forming region obtained with the Very Large Array with similar to 1."5 resolution and similar to 0.3 mJy rms sensitivity. For 10 objects, the circumstellar emission has been spatially resolved. The large outer disk radii derived suggest that the emission at this wavelength is mostly optically thin. The millimetre spectral energy distributions are characterised by spectral indices alpha(mm) = 2.3 to 3.2. After accounting for contributions from free-free emission and corrections for optical depth, we determine dust opacity indices beta in the range 0.5 to 1.6, which suggest that millimetre-sized dust aggregates are present in the circumstellar disks. Four of the sources with beta > 1 may be consistent with submicron-sized dust as found in the interstellar medium. Our findings indicate that dust grain growth to millimetre-sized particles is completed within less than 1 Myr for the majority of circumstellar disks.
引用
收藏
页码:211 / 221
页数:11
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