A New Line of Evidence for the Existence of Stellar Black Holes
Fran Primini
Smithsonian Astrophysical Observatory & Oregon State University
Friday, 4 April, 5:15 PM
Kidder 364, Oregon State University
As one might expect, observational evidence for the existence of black holes
is difficult to obtain. Until recently, the only such evidence derived from
the study of binary systems containing gravitationally collapsed objects in
close orbit about more normal stellar companions. For a number of such
systems, detailed study of the orbit indicates that the mass of the collapsed
object must be greater than the maximum allowed for a neutron star. The most
common interpretation is that these collapsed objects are black holes with
masses of a few solar masses. But since the evidence does not relate to any
property unique to black holes, other interpretations are also
allowed. Recently, however, astronomers have reported making observations
whose results indicate the presence of an event horizon --- a property unique
to black holes. If these observations are confirmed they will significantly
strengthen the case for the existence of stellar black holes.
In this talk, I'll review some of the classic evidence for the existence of
stellar black holes, and discuss the new evidence. I'll close with a
discussion of the relevance of the new evidence for the search for black holes
with masses of millions of solar masses.