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A second black hole candidate in a M31 globular cluster is identified with XMM-Newton

Barnard, R. and Kolb, U. (2009). A second black hole candidate in a M31 globular cluster is identified with XMM-Newton. Monthly Notices of the Royal Astronomical Society, 397 L92-L95.

DOI (Digital Object Identifier) Link: http://dx.doi.org/10.1111/j.1745-3933.2009.00691.x
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Abstract

We use arguments developed in previous work to identify a second black hole candidate associated with an M31 globular cluster (GC), Bo 144, on the basis of X-ray spectral and timing properties. The 2002 XMM–Newton observation of the associated X-ray source (hereafter XBo 144) revealed behaviour that is common to all low-mass X-ray binaries (LMXBs) in the low-hard state. Studies have shown that neutron star LMXBs exhibit this behaviour at 0.01–1000 keV luminosities ≤10 per cent of the Eddington limit (LEdd). However, the unabsorbed 0.3–10 keV luminosity of XBo 144 was ~0.30 LEdd for a 1.4 M neutron star, and the 0.01–1000 keV luminosity is expected to be ≳3–7 times higher. We therefore identify XBo 144 as a black hole candidate. Furthermore, it is the second black hole candidate to be consistent with formation via tidal capture of a main sequence donor in a GC; such systems were previously thought non-existent, because the donor was thought to be disrupted during the capture process.

Item Type: Journal Article
Copyright Holders: 2009 The Authors
ISSN: 1365-2966
Project Funding Details:
Funded Project NameProject IDFunding Body
Not SetNot SetSTFC
Extra Information: Please note: not all the mathematical symbols used in the abstract can be displayed
Keywords: black hole physics; galaxies: individual: M31; X-rays: binaries; X-rays: general
Academic Unit/Department: Science > Physical Sciences
Interdisciplinary Research Centre: Centre for Earth, Planetary, Space and Astronomical Research (CEPSAR)
eSTEeM
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Item ID: 24409
Depositing User: Ulrich Kolb
Date Deposited: 03 Nov 2010 12:59
Last Modified: 05 Mar 2014 10:27
URI: http://oro.open.ac.uk/id/eprint/24409
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