Are There Black Holes Among Classical Novae?
Session 9 -- Galactic X-Ray/Gamma-Ray Sources
Display presentation, Monday, 30, 1994, 9:20-6:30

## [9.04] Are There Black Holes Among Classical Novae?

P. Zhao and J.E. McClintock (SAO)

In 1993, we implemented a novel scheme to identify quiescent X-ray novae, the majority of which are outstanding black hole candidates.$^1$ ~The scheme, which relies solely on optical data, is based on the similarities between the light curves of X-ray novae and the light curves of some classical novae (binaries that contain a white dwarf). In the first part of the study, we used Duerbeck's catalog of 277 galactic novae$^2$ to select 46 northern objects that have light curves similar to those of X-ray novae. We then searched among these quiescent novae for the optical spectral signatures of a black-hole X-ray nova (e.g., very broad and double-peaked Balmer emission lines). To date we have netted several candidate black-hole binaries. In the second part of the study, we have begun to scrutinize each candidate by measuring its orbital period and the radial velocity curve of its secondary. These data determine the mass function of the primary; if it exceeds 3~M$_{\odot}$ for one of the systems, we will have discovered a new dynamical black hole candidate. We will present the results of our dynamical measurements. The observations were carried out using the MMT and 1.2-m telescope on Mt. Hopkins, AZ. \\

\noindent 1. van Paradijs, J. and McClintock, J.E. 1993, to appear in X-ray Binaries'', editors W.H.G. Lewin et al., Cambridge: Cambridge University Press.\\ 2. Duerbeck, H. W. 1987, A reference Catalogue and Atlas of Galactic Novae'', Reidel Publishing Co.