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

• Published in: Science (American Association for the Advancement of Science) Vol. 337; no. 6094; pp. 554 - 556
• Main Authors: Webb, Natalie, Cseh, David, Lenc, Emil, Godet, Olivier, Barret, Didier, Corbel, Stephane, Farrell, Sean, Fender, Robert, Gehrels, Neil, Heywood, Ian
• Format: Journal Article
• Language: English
• Published: Goddard Space Flight Center American Association for the Advancement of Science 03.08.2012; Science; The American Association for the Advancement of Science; American Association for the Advancement of Science (AAAS)
• Subjects: Astronomy; Astrophysics; Average linear density; Black holes; Earth, ocean, space; Exact sciences and technology; Fractions; Late stages of stellar evolution (including black holes); Luminosity; Physics; Point sources; Radio; Radio astronomy; Radio emission; Radio flares; Radio observatories; Relativistic jets; Stars; Supermassive black holes; X ray observatories; Transitions; Detections; Hole; Radio emission; Plasma; Galaxies; Black holes; Relativistic jet; Transition state; Cosmology
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.1222779

Relativistic jets are streams of plasma moving at appreciable fractions of the speed of light. They have been observed from stellar-mass black holes (∼3 to 20 solar masses, M ⊙ ) as well as supermassive black holes (∼10 6 to 10 9 M⊙) found in the centers of most galaxies. Jets should also be produced by intermediate-mass black holes (∼10 2 to 10 5 M ⊙ ), 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 ∼9 × 10 3 M ⊙ and ∼9 × 10 4 M ⊙ .