Sgr B2(N): A bipolar outflow and rotating hot core revealed by ALMA

Abstract

We present the results of SiO (2-1) and SO2 (12-13) line observations of Sgr B2(N) made with the Atacama Large Millimeter/submillimeter Array (ALMA) at an angular resolution of ~2arcsec. Our analysis of the SiO and SO2 line emission reveals a bipolar molecular outflow in an east-west direction whose driving source is located at K2. In addition, SO2 line core shows a north-south velocity gradient most probably indicating a hot core of molecular gas rotating around K2. Fractional abundances of SO2 and SiO (X(SO2) and X(SiO), respectively) in the outflowing molecular gas are derived from comparisons with the C18O emission. Assuming an excitation temperature of 100+-50 K, we calculate X(SO2) = 2.3X10^-8 and X(SiO) = 1.2X10^-9. The outflow from SgrB2(N) K2 is characterized as a young (5X10^3yr) and massive (~2000Msun), but moderately collimated (~60deg) outflow. We also report a possible detection of the SiO (v=2, J=2-1) maser emission from the position of K2. If confirmed, it would make Sgr B2(N) the 4th star forming region associated with SiO masers.

31 pages, 8 figures, ApJ accepted for publication

References in corpus (12)

• Detection of a branched alkyl molecule in the interstellar medium: iso-propyl cyanide
• SiO line emission from C-type shock waves : interstellar jets and outflows
• A Keplerian-like disk around the forming O-type star AFGL 4176
• A necklace of dense cores in the high-mass star forming region G35.20-0.74N: ALMA observations
• Subarcsecond Imaging of the NGC 6334 I(N) Protocluster: Two Dozen Compact Sources and a Massive Disk Candidate
• A Photoevaporating Rotating Disk in the Cepheus A HW2 Star Cluster
• Multi-line (sub)millimetre observations of the high-mass proto cluster IRAS 05358+3543
• ALMA reveals a candidate hot and compact disk around the O-type protostar IRAS 16547$-$4247
• Infall and Outflow of Molecular Gas in Sgr B2
• ALMA view of G0.253+0.016: Can cloud-cloud collision form the cloud?
• SiO excitation from dense shocks in the earliest stages of massive star formation
• IRAS16547-4247: A New Candidate of a Protocluster Unveiled with ALMA

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• ALMA Observations of Massive Clouds in the Central Molecular Zone: Ubiquitous Protostellar Outflows
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