Zooming in on a sleeping giant: milliarcsecond High Sensitivity Array imaging of the black hole binary V404 Cyg in quiescence
Observations of the black hole X-ray binary V404 Cyg with the very long baseline interferometer the High Sensitivity Array (HSA) have detected the source at a frequency of 8.4 GHz, providing a source position accurate to 0.3 mas relative to the calibrator source. The observations put an upper limit...
| Main Authors: | , , , , , , , |
|---|---|
| Format: | Journal Article |
| Published: |
Wiley-Blackwell Publishing Ltd.
2008
|
| Subjects: | |
| Online Access: | http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2966.2008.13495.x/full http://hdl.handle.net/20.500.11937/42925 |
| Summary: | Observations of the black hole X-ray binary V404 Cyg with the very long baseline interferometer the High Sensitivity Array (HSA) have detected the source at a frequency of 8.4 GHz, providing a source position accurate to 0.3 mas relative to the calibrator source. The observations put an upper limit of 1.3 mas on the source size (5.2 au at 4 kpc) and a lower limit of 7 × 10^6 K on its brightness temperature during the normal quiescent state, implying that the radio emission must be non-thermal, most probably synchrotron radiation, possibly from a jet. The radio light curves show a short flare, with a rise time of ~30 min, confirming that the source remains active in the quiescent state. |
|---|