Grain Growth and Density Distribution of the Youngest Protostellar Systems
Abstract
We present dust opacity spectral indexes (β) of the youngest protostellar systems (so-called Class 0 sources), L1448 IRS 2, L1448 IRS 3, and L1157, obtained between the λ = 1.3 mm and 2.7 mm continua, using the Combined Array for Research in Millimeter-wave Astronomy (CARMA). The unprecedented compact configuration and image fidelity of CARMA allow a better detection of the dust continuum emission from Class 0 sources, with a less serious missing flux problem normally associated with interferometry. Through visibility modeling at both λ = 1.3 mm and 2.7 mm simultaneously, as well as image and visibility comparison, we show that β of the three Class 0 sources are around or smaller than 1, indicating that dust grains have already significantly grown at the Class 0 stage. In addition, we find a radial dependence of β, which implies faster grain growth in the denser central regions and/or dust segregation. Density distributions of the Class 0 sources are also addressed by visibility modeling.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- May 2009
- DOI:
- 10.1088/0004-637X/696/1/841
- arXiv:
- arXiv:0902.2008
- Bibcode:
- 2009ApJ...696..841K
- Keywords:
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- circumstellar matter;
- stars: individual: L1448 IRS 2 L1448 IRS 3 L1157;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- 16 pages