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Bright radio emission from an ultraluminous stellar-mass microquasar in M 31

Middleton, Matthew J.; Miller-Jones, James C.A.; Markoff, Sera; Fender, Rob; Henze, Martin; Hurley-Walker, Natasha; Scaife, Anna M.M.; Roberts, Timothy P.; Walton, Dominic; Carpenter, John; Macquart, Jean-Pierre; Bower, Geoffrey C.; Gurwell, Mark; Pietsch, Wolfgang; Haberl, Frank; Harris, Jonathan; Daniel, Michael; Miah, Junayd; Done, Chris; Morgan, John S.; Dickinson, Hugh; Charles, Phil; Burwitz, Vadim; Della Valle, Massimo; Freyberg, Michael; Greiner, Jochen; Hernanz, Margarita; Hartmann, Dieter H.; Hatzidimitriou, Despina; Riffeser, Arno; Sala, Gloria; Seitz, Stella; Reig, Pablo; Rau, Arne; Orio, Marina; Titterington, David; Grainge, Keith

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Matthew J. Middleton

James C.A. Miller-Jones

Sera Markoff

Rob Fender

Martin Henze

Natasha Hurley-Walker

Anna M.M. Scaife

Dominic Walton

John Carpenter

Jean-Pierre Macquart

Geoffrey C. Bower

Mark Gurwell

Wolfgang Pietsch

Frank Haberl

Jonathan Harris

Michael Daniel

Junayd Miah

John S. Morgan

Hugh Dickinson

Phil Charles

Vadim Burwitz

Massimo Della Valle

Michael Freyberg

Jochen Greiner

Margarita Hernanz

Dieter H. Hartmann

Despina Hatzidimitriou

Arno Riffeser

Gloria Sala

Stella Seitz

Pablo Reig

Arne Rau

Marina Orio

David Titterington

Keith Grainge


A subset of ultraluminous X-ray sources (those with luminosities of less than 1040 erg s−1; ref. 1) are thought to be powered by the accretion of gas onto black holes with masses of ~5–20 , probably by means of an accretion disk2, 3. The X-ray and radio emission are coupled in such Galactic sources; the radio emission originates in a relativistic jet thought to be launched from the innermost regions near the black hole4, 5, 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 Way6, and the absorption of soft X-rays in the interstellar medium hinders the determination of 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 in the nearby galaxy M 31, whose peak luminosity exceeded 1039 erg s−1. 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 black hole of stellar mass. Continued radio and X-ray monitoring of such sources should reveal the causal relationship between the accretion flow and the powerful jet emission.


Middleton, M. J., Miller-Jones, J. C., Markoff, S., Fender, R., Henze, M., Hurley-Walker, N., …Grainge, K. (2013). Bright radio emission from an ultraluminous stellar-mass microquasar in M 31. Nature, 493(7431), 187-190.

Journal Article Type Article
Publication Date Jan 1, 2013
Deposit Date Mar 26, 2013
Publicly Available Date Jan 9, 2014
Journal Nature
Print ISSN 0028-0836
Electronic ISSN 1476-4687
Publisher Nature Research
Peer Reviewed Peer Reviewed
Volume 493
Issue 7431
Pages 187-190


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