J/AZh/79/738 Population model of binary stars in the Galaxy (Tutukov+, 2002) ================================================================================ A model for the population of binary stars in the Galaxy. Tutukov A.V., Yungelson L.R. =2002AZh....79..738T =2002ARep...46..667T ================================================================================ ADC_Keywords: Models, evolutionary ; Stars, double and multiple Abstract: A comparative study of the population of the galactic binary stars is performed for two modes of star formation: star formation at a constant rate over 10^+10^yrs, and a burst of star formation that reprocesses the same mass of gas into stars over 10^+9^yrs. Estimates are presented for the star formation rates and populations of about 100 types of binaries and the products of their evolution. File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file table1.dat 71 82 Close binaries: formation rate, products of their evolution and counts in various models table4.dat 69 47 Wide binaries: formation rate, products of their evolution and counts in various models -------------------------------------------------------------------------------- Byte-by-byte Description of file: table1.dat table4.dat ------------------------------------------------------------------------------- Bytes Format Units Label Explanations ------------------------------------------------------------------------------- 1- 5 A5 --- System Type of system (1) 7- 27 A21 --- SType Type of star or event (2) 29- 34 E6.2 yr-1 nuA Rate of binary formation in model A (3) 36- 41 E6.2 --- NA ? Number of close binaries for T=10^10^yrs in model A 43- 48 E6.2 yr-1 nuB ? Rate of binary formation in model B (4) 50- 55 E6.2 --- NB ? Number of close binaries for T=10^10^yrs in model B 57- 62 E6.2 yr-1 nuC ? Rate of binary formation in model C (5) 64- 70 E7.2 --- NC ? Number of close binaries for T=10^10^yrs in model C ------------------------------------------------------------------------------- Note (1): Type of binary system is designated as follows: MSS = Main-sequence stars SBH = Systems with black holes SNS = Systems with neutron stars SWD = Systems with white dwarfs SHS = Systems with helium stars SDS = Semi-detached systems CC = Coalescence of components CE = Common envelopes TZO = Thorne-Zytkov Objects CRO = Coalescence of relativistic objects SN = Supernovae IAHeL = Ignition of accreted He layer COND = Collapse of oxygen-neon dwarfs BH = Black holes NS = Neutron stars SGS = Subgiants, giants and supergiants HS = Helium stars WD = White dwarfs Note (2): Type of star or event is designated as follows: MS = main-sequence star BH = black hole XRS = X-ray source sd = semi-detached system SG = subgiant (a star with a helium core and hydrogen-burning layer) ONe = oxygen-neon-carbon white dwarf CO = carbon-oxygen white dwarf He = helium white dwarfs CO* = carbon-oxygen star R CrB*(CO) = R CrB star with detonating CO-core R CrB*(ONe) = R CrB star with collapsing ONe core HCE = system with a hydrogen common envelope HeCE = system with a helium common envelope TZ = Thorne-Zytkov objects G(He) = star in a stage of core He burning, AGB = star on the asymptotic giant branch Note (3): Model A: Continuus star formation over 10^+10^yrs with a constant rate. Common-envelope parameter, {alpha}=1 Blank entries correspond to cases when some type of system does not appear in the model at T=10 billion years Note (4): Model B: The star formation is as in a model A, but with {alpha}=0.5 Blank entries correspond to cases when some type of system does not appear in the model at T=10 billion years Note (5): Model C: The star formation occurs during the first 10^+9^yrs of the Galaxy's existence, at a constant rate, but exceeding one in the model A by the factor 10, and with {alpha}=1. Blank entries correspond to cases when some type of system does not appear in the model at T=10 billion years ------------------------------------------------------------------------------- Table2. Rate of formation of single black holes via different channels (yr-1). -------------------------------------------------------------------------------- Channels |__________Model_____________ | A B C -------------------------------------------------------------------------------- Disruption of binaries 1.3E-4 1.3E-4 0.0 Coalescence of black holes 1.2E-5 3.8E-5 8.8E-6 Coalescence of neutron stars and black holes 5.8E-5 7.8E-5 1.5E-5 Coalescence of neutron stars 1.5E-4 8.5E-5 3.9E-5 Evolution of the single products of coalescence 1.1E-5 2.0E-5 0.0 Coalescence of black holes with white dwarfs 2.9E-5 5.9E-5 6.3E-6 -------------------------------------------------------------------------------- Table3. Current rate of formation of single neutron stars in close binaries via the main channels (yr-1). -------------------------------------------------------------------------------- Channels |__________Model_____________ | A B C -------------------------------------------------------------------------------- Disruption of binaries 3.1E-3 2.4E-4 0.0 Evolution of the single products of coalescence 3.5E-3 5.4E-3 0.0 Coalescence of white dwarfs 9.0E-4 1.3E-4 3.7E-5 Core collapse of R CrB stars 5.3E-4 5.0E-4 0.0 Coalescence of neutron stars with white dwarfs 1.2E-3 7.5E-4 1.2E-4 Coalescence of neutron stars with MS stars 3.9E-4 9.8E-4 0.0 -------------------------------------------------------------------------------- ================================================================================ (End) Veta Avedisova (INASAN) 01-Oct-2002