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Title: XMM-Newton observations of the Galactic Centre Region - II. The soft-thermal emission
Authors: Heard, V.
Warwick, Robert Seymour
First Published: 9-Jul-2013
Publisher: Oxford University Press (OUP)
Citation: Monthly Notices Of The Royal Astronomical Society, 2013, 434 (2), pp. 1339-1354 (16)
Abstract: We have extended our earlier study of the X-ray emission emanating from the central 100 pc × 100 pc region of our Galaxy to an investigation of several features prominent in the soft X-ray (2–4.5 keV) band. We focus on three specific structures: a putative bipolar outflow from the vicinity of Sgr A*; a high surface brightness region located roughly 12 arcmin (25 pc) to the north-east of Sgr A* and a lower surface brightness extended loop feature seen to the south of Sgr A*. We show, unequivocally, that all three structures are thermal in nature and have similar temperatures (kT ≈ 1 keV). The inferred X-ray luminosities lie in the range (2–10) × 10[Superscript: 34] erg s[Superscript: −1]. In the case of the bipolar feature we suggest that the hot plasma is produced by the shock heating of the winds from massive stars within the Central Cluster, possibly collimated by the Circumnuclear Disc. Alternatively the outflow may be driven by outbursts on Sgr A*, which follow tidal disruption events occurring at a rate of roughly one every 4000 yr. The north-east enhancement is centred on a candidate pulsar wind nebula which has a relatively hard non-thermal X-ray spectrum. We suggest that the coincident soft-thermal emission traces the core of a new thermal-composite supernova remnant, designated as SNR G0.13−0.12. There is no clear evidence for an associated radio shell but such a feature may be masked by the bright emission of the nearby Radio Arc and other filamentary structures. SNR G0.13−0.12 is very likely interacting with the nearby molecular cloud, G0.11−0.11, and linked to the Fermi source, 2FGL J1746.4−2851c. Finally we explore a previous suggestion that the elliptically shaped X-ray loop to the south of Sgr A*, of maximum extent ∼45 pc, represents the shell of a superbubble located in the GC region. Although plausible, the interpretation of this feature in terms a coherent physical structure awaits confirmation.
DOI Link: 10.1093/mnras/stt1102
ISSN: 0035-8711
eISSN: 1365-2966
Version: Publisher Version
Status: Peer-reviewed
Type: Journal Article
Rights: This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society ©: 2013 The Author. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved. Deposited with reference to the publisher’s archiving policy available on the SHERPA/RoMEO website.
Appears in Collections:Published Articles, Dept. of Physics and Astronomy

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