The first accurate parallax distance to a black hole
Abstract
Using astrometric VLBI observations, we have determined the parallax of the black hole X-ray binary V404 Cyg to be 0.418 +/- 0.024 milliarcseconds, corresponding to a distance of 2.39 +/- 0.14 kpc, significantly lower than the previously accepted value. This model-independent estimate is the most accurate distance to a Galactic stellar-mass black hole measured to date. With this new distance, we confirm that the source was not super-Eddington during its 1989 outburst. The fitted distance and proper motion imply that the black hole in this system likely formed in a supernova, with the peculiar velocity being consistent with a recoil (Blaauw) kick. The size of the quiescent jets inferred to exist in this system is less than 1.4 AU at 22 GHz. Astrometric observations of a larger sample of such systems would provide useful insights into the formation and properties of accreting stellar-mass black holes.
Cite
@article{arxiv.0910.5253,
title = {The first accurate parallax distance to a black hole},
author = {J. C. A. Miller-Jones and P. G. Jonker and V. Dhawan and W. Brisken and M. P. Rupen and G. Nelemans and E. Gallo},
journal= {arXiv preprint arXiv:0910.5253},
year = {2014}
}
Comments
Accepted for publication in ApJ Letters. 6 pages, 2 figures