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arXiv · 1401.6986

First results from the CALYPSO IRAM-PdBI survey. I. Kinematics of the inner envelope of NGC1333-IRAS2A

S. Maret·A. Belloche·A. J. Maury·F. Gueth·Ph. André·S. Cabrit·C. Codella·S. Bontemps
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Abstract

The structure and kinematics of Class 0 protostars on scales of a few hundred AU is poorly known. Recent observations have revealed the presence of Keplerian disks with a diameter of 150-180 AU in L1527-IRS and VLA1623A, but it is not clear if such disks are common in Class 0 protostars. Here we present high-angular-resolution observations of two methanol lines in NGC1333-IRAS2A. We argue that these lines probe the inner envelope, and we use them to study the kinematics of this region. Our observations suggest the presence of a marginal velocity gradient normal to the direction of the outflow. However, the position velocity diagrams along the gradient direction appear inconsistent with a Keplerian disk. Instead, we suggest that the emission originates from the infalling and perhaps slowly rotating envelope, around a central protostar of 0.1-0.2 M$_\odot$. If a disk is present, it is smaller than the disk of L1527-IRS, perhaps suggesting that NGC1333-IRAS2A is younger.

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S. Maret, A. Belloche, A. J. Maury, F. Gueth, Ph. André, S. Cabrit, C. Codella, S. Bontemps. 2014-01-27. First results from the CALYPSO IRAM-PdBI survey. I. Kinematics of the inner envelope of NGC1333-IRAS2A. https://doi.org/10.1051/0004-6361/201323028

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