Bright radio emission from an ultraluminous stellar-mass microquasar in M31
Abstract
A subset of ultraluminous X-ray sources (those with luminosities < 10^40 erg/s) are thought to be powered by the accretion of gas onto black holes with masses of ~5-20 M_solar, probably via an accretion disc. The X-ray and radio emission are coupled in such Galactic sources, with the radio emission originating in a relativistic jet thought to be launched from the innermost regions near the black hole, with the most powerful emission occurring when the rate of infalling matter approaches a theoretical maximum (the Eddington limit). Only four such maximal sources are known in the Milky Way, and the absorption of soft X-rays in the interstellar medium precludes determining the causal sequence of events that leads to the ejection of the jet. Here we report radio and X-ray observations of a bright new X-ray source whose peak luminosity can exceed 10^39 erg/s in the nearby galaxy, M31. The radio luminosity is extremely high and shows variability on a timescale of tens of minutes, arguing that the source is highly compact and powered by accretion close to the Eddington limit onto a stellar mass black hole. Continued radio and X-ray monitoring of such sources should reveal the causal relationship between the accretion flow and the powerful jet emission.
Cite
@article{arxiv.1212.4698,
title = {Bright radio emission from an ultraluminous stellar-mass microquasar in M31},
author = {Matthew J. Middleton and James C. A. Miller-Jones and Sera Markoff and Rob Fender and Martin Henze and Natasha Hurley-Walker and Anna M. M. Scaife and Timothy P. Roberts and Dominic Walton and John Carpenter and Jean-Pierre Macquart and Geoffrey C. Bower and Mark Gurwell and Wolfgang Pietsch and Frank Haberl and Jonathan Harris and Michael Daniel and Junayd Miah and Chris Done and John Morgan and Hugh Dickinson and Phil Charles and Vadim Burwitz and Massimo Della Valle and Michael Freyberg and Jochen Greiner and Margarita Hernanz and Dieter H. Hartmann and Despina Hatzidimitriou and Arno Riffeser and Gloria Sala and Stella Seitz and Pablo Reig and Arne Rau and Marina Orio and David Titterington and Keith Grainge},
journal= {arXiv preprint arXiv:1212.4698},
year = {2015}
}
Comments
23 pages, 4 figures accepted by Nature (AOP 12/12/12)