Black holes: Beyond the Galaxy

A paper that demonstrates the potential of Very Long Baseline Interferometry reports the determination of the space velocity of a black hole in the halo of the Milky Way. Only a few of the dozen known stellar-mass black holes lie out of the plane of our Galaxy. These bodies could have been shot out from the Galaxy as a result of a 'kick' from a supernova explosion, or could be the remains of massive stars formed early during the life of the Galaxy. The calculated orbit of the black hole XTE J1118+480 virtually rules out the supernova 'kick' model, suggesting that it is part of the old halo component. An animation of the processes thought to be involved can be found on http://www.iafe.uba.ar/astronomia/FM/mirabel.html.

letters to nature
A high-velocity black hole on a Galactic-halo orbit in the solar neighbourhood
I. F. MIRABEL, V. DHAWAN, R. P. MIGNANI, I. RODRIGUES & F. GUGLIELMETTI
Nature 413, 139–141 (13 September 2001)
| First Paragraph | Full Text | PDF (192 K) |

feature of the week
Wandering star

13 September 2001 table of contents