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La Freccia Rossa: an IR-dark cloud hosting the Milky Way intermediate-mass black hole candidate

Ravi, Vikram and Vedantham, Harish and Phinney, E. Sterl (2018) La Freccia Rossa: an IR-dark cloud hosting the Milky Way intermediate-mass black hole candidate. Monthly Notices of the Royal Astronomical Society: Letters, 478 (1). L72-L77. ISSN 1745-3925. doi:10.1093/mnrasl/sly077.

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The dynamics of the high-velocity compact molecular cloud CO-0.40-0.22 have been interpreted as evidence for a ∼10^5 M_⊙ black hole within 60 pc of Sgr A*. Recently, Oka et al. have identified a compact millimetre-continuum source, CO-0.40-0.22*, with this candidate black hole. Here we present a collation of radio and infrared data at this location. Australia Telescope Compact Array constraints on the radio spectrum, and the detection of a mid-infrared counterpart, are in tension with an Sgr A*-like model for CO-0.40-0.22* despite the comparable bolometric to the Eddington luminosity ratios under the intermediate-mass black hole interpretation. A protostellar-disc scenario is, however, tenable. CO-0.40-0.22(*) is positionally coincident with an arrowhead-shaped infrared-dark cloud (which we call the Freccia Rossa). If the V_(LSR) ≈ 70 km s^(−1) systemic velocity of CO-0.40-0.22 is common to the entire Freccia Rossa system, we hypothesize that it is the remnant of a high-velocity cloud that has plunged into the Milky Way from the Galactic halo.

Item Type:Article
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URLURL TypeDescription Paper
Ravi, Vikram0000-0002-7252-5485
Vedantham, Harish0000-0002-0872-181X
Additional Information:© 2018 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society. This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model ( Accepted 2018 April 29. Received 2018 April 09; in original form 2017 October 10. We thank the referee for helping in improving the presentation of the manuscript, and Mattia Sormani for pointing out the possibility of bar-induced motions. We are grateful to the staff of Commonwealth Scientific and Inductrial Research Organisation (CSIRO) Astronomy and Space Science for rapidly scheduling our observations. The Australia Telescope Compact Array is a part of the Australia Telescope National Facility that is funded by the Australian Government for operation as a National Facility managed by CSIRO. ESP’s research was funded in part by the Gordon and Betty Moore Foundation through grant GBMF5076. This work is based in part on observations made with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology under a contract with National Aeronautics and Space Administration. This research has made use of the SIMBAD data base, operated at Centre de donees astronomiques de Strasbourg, Strasbourg, France.
Group:TAPIR, Astronomy Department
Funding AgencyGrant Number
Commonwealth Scientific and Research Organization (CSIRO)UNSPECIFIED
Gordon and Betty Moore FoundationGBMF5076
Subject Keywords:black hole physics, radiation mechanisms: general, stars: formation, ISM: clouds, dust, extinction, Galaxy: halo
Issue or Number:1
Record Number:CaltechAUTHORS:20181205-163501087
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Official Citation:Vikram Ravi, Harish Vedantham, E Sterl Phinney; La Freccia Rossa: an IR-dark cloud hosting the Milky Way intermediate-mass black hole candidate, Monthly Notices of the Royal Astronomical Society: Letters, Volume 478, Issue 1, 21 July 2018, Pages L72–L77,
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:91522
Deposited By: George Porter
Deposited On:07 Dec 2018 15:31
Last Modified:16 Nov 2021 03:41

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