Radio Detections During Two State Transitions of the Intermediate-Mass Black Hole HLX-1

Natalie Webb (1, 2) , David Cseh (3) , Emil Lenc (4) , Olivier Godet (1, 2) , Didier Barret (1, 2) , Stephane Corbel (3) , Sean Farrell (1) , Robert Fender (5) , Neil Gehrels (6) , Ian Heywood (7)

1 IRAP - Institut de recherche en astrophysique et planétologie
2 UT - Université de Toulouse
3 AIM (UMR7158 / UMR_E_9005 / UM_112) - Astrophysique Interprétation Modélisation
4 ATNF - Australia Telescope National Facility
5 School of Physics and Astronomy [Southampton]
6 Astroparticle Physics Laboratory [Greenbelt]
7 Department of Physics [Oxford]

Relativistic jets are streams of plasma moving at appreciable fractions of the speed of light. They have been observed from stellar-mass black holes ($\sim$3$-$20 solar masses, M$_ \odot$) as well as supermassive black holes ($\sim$10$^6$$-$10$^9$ M$_\odot$) found in the centers of most galaxies. Jets should also be produced by intermediate-mass black holes ($\sim$10$^2$-$10^5$ M$_ \odot$), although evidence for this third class of black hole has, until recently, been weak. We report the detection of transient radio emission at the location of the intermediate-mass black hole candidate ESO 243-49 HLX-1, which is consistent with a discrete jet ejection event. These observations also allow us to refine the mass estimate of the black hole to be between $\sim$9 × 10$^3$ M$_\odot$ and $\sim$9 × 10$^4$ M$_\odot$.

Domains: Physics [physics]; Astrophysics [astro-ph]

Natalie Webb, David Cseh, Emil Lenc, Olivier Godet, Didier Barret, et al.. Radio Detections During Two State Transitions of the Intermediate-Mass Black Hole HLX-1. Science, 2012, 337 (6094), pp.554-556. ⟨10.1126/science.1222779⟩. ⟨cea-00862697⟩