A Comprehensive Study of Young Black Hole Populations.pdfVIP

Submitted to The Astrophysical Journal (April 2, 2004) A Preprint typeset using LT X style emulateapj v. 5/14/03 E A COMPREHENSIVE STUDY OF YOUNG BLACK HOLE POPULATIONS 1,2 3 1 Krzysztof Belczynski , Aleksander Sadowski , Frederic A. Rasio 1 Northwestern University, Dept of Physics and Astronomy, 2145 Sheridan Rd, Evanston, IL 60208 2 Lindheimer Postdoctoral Fellow 3 Warsaw University, Dept. of Physics, Hoza 69, 00-681, Warsaw, Poland belczynski, rasio@northwestern.edu; oleks@camk.edu.pl Submitted to The Astrophysical Journal (April 2, 2004) ABSTRACT We present theoretical models of black hole (BH) populations in young stellar environments, such as 4 starbursts and young star clusters. Using a population synthesis approach we compute the formation 0 rates and characteristic properties of single and binary BHs for various representative ages and choices 0 of parameters. We find that most of the BHs (typically 80% for an initial 50% binary fraction) are 2 single, but with many originating from primordial binaries (which either merged into a single massive r star or were disrupted following a supernova explosion). A smaller but significant fraction (typically p 20%) of the BHs remain in binary systems. Main-sequence stars are the most frequent BH companions, A