title: Radio detections during two state transitions of the intermediate-mass black hole HLX-1.
abstract: 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(⊙).
authors: Université de Toulouse, UPS-OMP, IRAP, F-31028 Toulouse, France. natalie.webb@irap.omp.eu
authors: Natalie
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authors: Webb
authors: David
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authors: Godet
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authors: Barret
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authors: Heywood