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Deep observations with the Very Large Array of A0620–00, performed in 2005 August, resulted in the first detection of radio emission from a black hole binary at X-ray luminosities as low as 10 times the Eddington limit. The measured radio flux density, of 51± 7 μJy at 8.5 GHz, is the lowest reported for an X-ray binary system so far, and is interpreted in(More)
Several independent lines of evidence now point to a connection between the physical processes that govern radio (i.e. jet) and X–ray emission from accreting X–ray binaries. We present a comprehensive study of (quasi–)simultaneous radio:X–ray observations of stellar black hole binaries during the spectrally hard X–ray state, finding evidence for a strong(More)
Black holes undergoing accretion are thought to emit the bulk of their power in the X-ray band by releasing the gravitational potential energy of the infalling matter. At the same time, they are capable of producing highly collimated jets of energy and particles flowing out of the system with relativistic velocities. Here we show that the 10-solar-mass(More)
We demonstrate that at relatively low mass accretion rates, black hole candidate (BHC) X-ray binaries (XRBs) should enter ‘jet-dominated’ states, in which the majority of the liberated accretion power is in the form of a (radiatively inefficient) jet and not dissipated as X-rays in the accretion flow. This result follows from the empirically established(More)
We report on the formation and evolution of a large-scale, synchrotron-emitting jet from the black hole candidate and X-ray binary system GX 339−4. In 2002 May, the source moved from a low/hard to a very high X-ray state, contemporaneously exhibiting a very bright optically thin radio flare. Further observations with the Australia Telescope Compact Array(More)
A large sample of AGN studied here shows a “quenching” of the radio emission occurs when the luminosity is at a few percent to about 10% of the Eddington rate, just as is seen in the high/soft state of X-ray binaries. The result holds even when the sample of AGN includes no Narrow Line Seyfert 1 galaxies (the systems most commonly suggested to be the analog(More)
Observations of V404 Cyg performed with the Westerbork Synthesis Radio Telescope at four frequencies, over the interval 1.4−8.4 GHz, have provided us with the first broadband radio spectrum of a ‘quiescent’ stellar mass black hole. The measured mean flux density is of 0.35 mJy, with a spectral index α = +0.09±0.19 (such that Sν ∝ ν). Synchrotron emission(More)
We present the first results from the AGN Multiwavelength Survey of Early-type galaxies in the Virgo cluster (AMUSE-Virgo). This large program targets 100 early-type galaxies with the Advanced CCD Imaging Spectrometer on board the Chandra X-ray Observatory and the Multi-band Imaging Photometer on board the Spitzer Space Telescope, with the aim of providing(More)
Among the various issues that remain open in the field of accretion onto black hole X-ray binaries (BHBs) is the way the gas accretes at very low Eddington ratios, in the so-called quiescent regime. While there is general agreement that the X-rays are produced by a population of high-energy electrons near to the BH, the controversy comes about in modeling(More)