David Cseh

Publications (2)31.2 Total impact

• Article: Radio detections during two state transitions of the intermediate-mass black hole HLX-1.

  Natalie Webb, David Cseh, Emil Lenc, Olivier Godet, Didier Barret, Stephane Corbel, Sean Farrell, Robert Fender, Neil Gehrels, Ian Heywood
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  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(⊙).
  Science 07/2012; 337(6094):554-6. · 31.20 Impact Factor
• Article: Verifying the intermediate mass black hole nature of the ultraluminous X-ray source HLX-1 associated with ESO 243-49

  Natalie Webb, Emil Lenc, Stephane Corbel, Rob Fender, Ian Heywood, Sean Farrell, Didier Barret, David Cseh, Olivier Godet
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  ABSTRACT: We request a deep radio observation of the new ultra luminous X-ray source HLX-1, with ATCA, to verify its intermediate mass black hole nature. The X-ray luminosity indicates a minimum black hole mass of 500 solar masses, alluding to a much sought after intermediate mass black hole. Radio observations will allow us to determine or at least allow us to place an upper limit on the mass to enable us to confirm the intermediate mass black hole nature. These observations will be made when the source transits between the low/hard state to the high/soft state. During these transitions, Galactic black hole binaries have been shown to exhibit radio flares that are a factor ten brighter than the non-flaring radio emission. This Target of Opportunity observation will be triggered using Swift weekly/bi-weekly observations that will reveal when the transition between the states occurs and provide us with the simultaneous X-ray observations necessary to constrain the mass. This is currently one of the best candidates for an intermediate mass black hole, the possible building blocks of supermassive black holes found in the centres of many galaxies.
  ATNF Proposal. 03/2010; -1:3256.