Cookies

We use cookies to ensure that we give you the best experience on our website. You can change your cookie settings at any time. Otherwise, we'll assume you're OK to continue.

Durham University

Department of Physics

Staff profile

Publication details for Prof Tim Roberts

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 (2013). Bright radio emission from an ultraluminous stellar-mass microquasar in M 31. Nature 493(7431): 187-190.

Author(s) from Durham

Abstract

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.