Calculated Luminosity and Period Distributions for\hfil\break Cataclysmic Variables in Globular Clusters
Session 69 -- Cataclysmic Variables and Pulsars
Oral presentation, Thursday, 10:30-12:00, Dwinelle 155 Room

## [69.02] Calculated Luminosity and Period Distributions for\hfil\break Cataclysmic Variables in Globular Clusters

R. Di\thinspace Stefano (MIT, NYIT), S. Rappaport (MIT)

\noindent We have carried out simulations of the formation, via two-body tidal capture, and the subsequent evolution of cataclysmic variables in globular clusters. These results are used to estimate a lower bound on the number of cataclysmic variables that should be active in globular clusters during the present epoch. Our estimates are based on Monte Carlo simulations combined with evolution calculations appropriate to each binary system formed during the lifetime of two specific globular clusters, $\omega$ Cen, and 47 Tuc. Because we track the evolution of each system, we are able to predict the present day distributions of both orbital period and luminosity.

From our study of these two clusters, which represent the range of core densities and states of mass segregation that are likely to be interesting, we extrapolate our results to the Galactic globular cluster system. Although there is at present little direct observational evidence of cataclysmic variables in globular clusters, we find that there should be a large number of active systems. In particular, we predict that there are about $100$ cataclysmic variables in both 47 Tuc and $\omega$ Cen, and several thousand in the Galactic globular cluster system.

Our calculated luminosity distributions lead to the conclusion that the $\sim 25$ sources, with $10^{32} < L_x < 10^{34.5}$ ergs s$^{-1}$, observed in globular clusters can be accounted for by cataclysmic variables. On the other hand, the predicted integrated luminosities of the lower luminosity sources ($10^{30.5} < L_x < 10^{32}$ ergs s$^{-1}$), in a number of clusters, may be too high to be consistent with limits that can already be set by using the Einstein and Rosat observations. We utilize these results to constrain the formation scenarios for CVs in globular clusters.