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Spectral imaging of the Sagittarius B2 region in multiple 3-mm molecular lines with the Mopra telescope

Jones, P. A. and Burton, M. G. and Cunningham, M. R. and Menten, K. M. and Schilke, P. and Belloche, A. and Leurini, S. and Ott, J. and Walsh, A. J. (2008) Spectral imaging of the Sagittarius B2 region in multiple 3-mm molecular lines with the Mopra telescope. Monthly Notices of the Royal Astronomical Society, 386 (1). pp. 117-137. ISSN 0035-8711. doi:10.1111/j.1365-2966.2008.13009.x.

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Using the Mopra telescope, we have undertaken a 3-mm spectral-line imaging survey of a 5 × 5 arcmin^2 area around Sgr B2. We covered almost the complete spectral range from 81.7 to 113.5 GHz, with 2.2 MHz wide spectral channels or ~6 km s^−1 and have observed 24 lines, with 0.033 MHz wide, or ~0.1 km s^−1 channels. We discuss the distribution of around 50 lines, and present velocity-integrated emission images for 38 of the lines. In addition, we have detected around 120 more lines, mostly concentrated at the particularly spectral-line-rich Sgr B2(N) source. There are significant differences in molecular emission, pointing to both abundance and excitation differences throughout the region. Seven distinct spatial locations are identified for the emitting species, including peaks near the prominent star-forming cores of Sgr B2(N), (M) and (S) that are seen in infrared (IR)-to-radio continuum images. The other features are a 'north ridge' and a 'north cloud' to the north of the Sgr B2 N-M-S cores, a 'south-east peak' and a 'west ridge'. The column density, as evident through C18O, peaks at the Sgr B2(N) and (M) cores, where strong absorption is also evident in otherwise generally bright lines such as HCO+, HCN and HNC. Most molecules trace a ridge line to the west of the Sgr B2 N-M-S cores, wrapping around the cores and extending north-east to the north cloud. This is most clearly evident in the species HC3N, CH3CN, CH3OH and OCS. They are found to be closer in distribution to the cooler dust traced by the submillimetre continuum than either the warmer dust seen in the mid-IR or to the radio continuum. The molecule CN, in contrast, is reasonably uniform over the entire region mapped, aside from strong absorption at the positions of the Sgr B2(N) and (M) cores.

Item Type:Article
Related URLs:
URLURL TypeDescription
Menten, K. M.0000-0001-6459-0669
Schilke, P.0000-0003-2141-5689
Ott, J.0000-0001-8224-1956
Additional Information:© 2008 The Authors. Journal compilation © 2008 RAS. Accepted 2008 January 23. Received 2008 January 22; in original form 2007 December 3. Published Online: 6 March 2008. The Mopra telescope is funded by the Commonwealth of Australia as a National Facility managed by CSIRO as part of the Australia Telescope. The UNSW MOPS digital filter bank was provided with funding from the Australian Research Council, University of New South Wales, Sydney University, Macquarie University and the CSIRO ATNF. PAJ thanks the Max-Planck-Institut für Radioastronomie, Bonn, for a Visiting Fellowship in 2006, and the anonymous referee for comments that improved the presentation of the paper. [J.O. was a] Jansky Fellow of the National Radio Astronomy Observatory.
Funding AgencyGrant Number
Commonwealth of AustraliaUNSPECIFIED
Australian Research CouncilUNSPECIFIED
University of New South WalesUNSPECIFIED
Sydney UniversityUNSPECIFIED
Macquarie UniversityUNSPECIFIED
Commonwealth Scientific and Research Organization (CSIRO)UNSPECIFIED
Max-Planck-Institut für RadioastronomieUNSPECIFIED
National Radio Astronomy ObservatoryUNSPECIFIED
Subject Keywords:ISM: individual: Sagittarius B2 • ISM: kinematics and dynamics • ISM: molecules • radio lines: ISM
Issue or Number:1
Record Number:CaltechAUTHORS:JONmnras08
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:12814
Deposited By: Archive Administrator
Deposited On:24 Dec 2008 22:58
Last Modified:08 Nov 2021 22:33

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