J/A+A/487/1129Evolutionary models of binaries (Van Rensbergen+, 2008)

Spin-up and hot spots can drive mass out of a binary. Van Rensbergen W., De Greve J.P., De Loore C., Mennekens N. <Astron. Astrophys. 487, 1129 (2008)> =2008A&A...487.1129VADC_Keywords: Binaries, eclipsing ; Models, evolutionaryKeywords: binaries: eclipsing - stars: evolution - stars: mass-loss - stars: statisticsAbstract: The observed distribution of orbital periods of Algols with a B-type primary at birth agrees fairly well with the prediction from conservative theory. Conservative evolution fails, however, to produce the rather large fraction of Algols observed with a high mass-ratio. In order to keep Algols for a longer time with a higher mass-ratio without disturbing the distribution of orbital periods too much, interacting binaries have to lose a significant fraction of their total mass without losing much angular momentum before or during Algolism. We propose a mechanism that meets both requirements. In the case of direct impact the gainer spins up: sometimes up to critical velocity. Equatorial material on the gainer is therefore less bound. A similar statement applies to material located at the edge of an accretion disc. The incoming material moreover creates a hot spot in the area of impact. The sum of the rotational and radiative energy of hot spot material depends on the mass- transfer-rate. The sum of both energies overcomes the binding energy at a well defined critical value of the mass-transfer-rate. As long as the transfer-rate is smaller than this critical value RLOF happens conservatively. But as soon as the critical rate is exceeded the gainer will acquire no more than the critical value and RLOF runs into a liberal era.Description: This catalogue contains the data needed to follow-up the liberal evolution of binaries with a B-type primary at birth. Loss of mass and angular momentum is included according to the scenario as outlined in the paper. Tables are labeled with: * Mass of the initial primary in solar masses * Type of tidal interaction ("strong" or "weak") or conservative evolution ("conser") For example: "09strong" signifies an initial 9 solar mass primary and strong tidal interactions (fsync=0.1), while "09weak" signifies weak tidal interactions (fsync=1.0). "09conser" assumes conservative evolution. When systems evolve conservatively, the evolutionary path does not depend on the type of tidal interaction. Therefore, in the case of 3 and 4 solar mass primaries, only the "conser" tables are given. Binaries with a 5 solar mass primary evolve almost conservatively, with very small differences between strong and weak tides. The table "05strong" contains mostly conservative calculations, and only the strong assumption if mass is lost from the system. At 6 solar mass primaries and above, "conser" tables are always given for comparison. Each table contains the evolutionary tracks for multiple combinations of the initial mass ratio and orbital period. The beginning of each evolution is characterized by a step=1. The tables start with the lowest mass ratio and the lowest orbital period, running through increasing periods before going to higher mass ratios.File Summary:

FileName Lrecl Records Explanations

ReadMe 80 . This file summary.dat 60 561 Summary of initial parameters in the models mod/* 160 21 Individual tables

Byte-by-byte Description of file: summary.dat

Bytes Format Units Label Explanations

1- 11 A11 "D-M-Y" Date Date of file addition or extension 13- 24 A12 --- FileName Name of the file, in "mod" subdirectory 27- 31 I5 --- Line Starting line number (from 0) of model 34- 37 I4 --- steps Number of steps in file with these parameters 39 A1 --- Case [wsc] (w)eak or (s)trong tidal interaction or (c)onservative case 41- 46 F6.3 solMass Mass1 Initial mass of primary 48- 53 F6.3 d Per Orbital period of the binary 55- 60 F6.3 solMass Mass2 Initial mass of secondary

Byte-by-byte Description of file: mod/*

Bytes Format Units Label Explanations

1- 4 I4 --- step Step in model (1 for Age=0) 6- 16 E11.6 yr Age Age 18- 23 F6.3 solMass Mass1 Mass of initial primary 25- 34 E10.5 solMass/yr Mdot1 Mass loss of initial primary 36- 40 F5.3 K Teff1 Log of effective temperature of initial primary 42- 47 F6.3 solLum Lum1 Log of luminosity of initial primary 49- 53 F5.3 --- Xc1 Hydrogen fraction (by mass) in core of initial primary 55- 59 F5.3 --- Yc1 Helium fraction (by mass) in core of initial primary 61- 65 F5.3 --- Xat1 Hydrogen fraction (by mass) in atmosphere of initial primary 67- 73 F7.3 solRad Rad1 Radius of initial primary 75- 81 F7.3 d Per Orbital period 83- 88 F6.3 solMass Mass2 Mass of initial secondary 90-100 E11.5 solMass/yr Mdot2 Mass loss of initial secondary 102-106 F5.3 K Teff2 Log of effective temperature of initial secondary 108-112 F5.3 solLum Lum2 Log of luminosity of initial secondary 114-118 F5.3 --- Xc2 Hydrogen fraction (by mass) in core of initial secondary 120-124 F5.3 --- Yc2 Helium fraction (by mass) in core of initial secondary 126-130 F5.3 --- Xat2 Hydrogen fraction (by mass) in atmosphere of secondary 132-138 F7.3 solRad Rad2 Radius of initial secondary 140-146 F7.3 solRad RRoche1 Roche radius of initial primary 148-154 F7.3 solRad RRoche2 Roche radius of initial secondary 156-160 F5.3 --- beta Mass gain / Mass loss ratio (1)

Note (1): Beta is the mass gain rate of the initial secondary (gainer) divided by the mass loss rate of the initial primary (donor) during RLOF (Roche Lobe Overflow). This quantity has no meaning outside RLOF and is put equal to 1 at that time.

Acknowledgements: N. Mennekens, nmenneke(at)vub.ac.beHistory: * 12-Aug-2008: First version * 20-Aug-2008: New version * 05-Sep-2008: New files added (details in the "summary.dat" file) * 21-Sep-2008: File "summary.dat" added * 27-Nov-2008: New files added (details in the "summary.dat" file) * 20-Mar-2009: New files added (details in the "summary.dat" file) * 03-May-2010: New files added (details in the "summary.dat" file)(End)W. Van Rensbergen [Vrije Univ. Brussel], P. Vannier [CDS] 20-Aug-2008

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