J/A+A/624/A66ivo://CDS.VizieR/J/A+A/624/A66doi:10.26093/cds/vizier.36240066CDSRenzo M.Zapartas E.de Mink S.E.Goetberg Y.Justham S.Farmer R.J.,Izzard R.G.Toonen S.Sana H.2020-11-13T15:15:26Z2019-04-11T09:06:04ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frastronomical-modelssupernovaemultiple-starsWe perform an extensive numerical study of the evolution of massive binary systems to predict the peculiar velocities that stars obtain when their companion collapses and disrupts the system. Our aim is to (i) identify which predictions are robust against model uncertainties and assess their implications, (ii) investigate which physical processes leave a clear imprint and may, therefore, be constrained observationally and (iii) provide a suite of publicly available model predictions, to allow for the use of kinematic constraints from the Gaia mission. We find that 22^+26^_-8_% of all massive binary systems merge prior to the first core-collapse in the system. Of the remainder, 86^+11^_-9_% become unbound because of the core-collapse. Remarkably, this rarely produce runaway stars (observationally defined as stars with velocities above 30km/s). These are outnumbered by more than an order of magnitude by slower unbound companions, or "walkaway stars". This is a robust outcome of our simulations and is due to the reversal of the mass ratio prior to the explosion and widening of the orbit, as we show analytically and numerically. For stars more massive than 15M_{sun}_, we estimate that 10^+5^_-8_% are walkaways and only 0.5^+1.0^_-0.4_% are runaways, nearly all of which have accreted mass from their companion. Our findings are consistent with earlier studies, however, the low runaway fraction we find is in tension with observed fractions of about 10%. Thus, astrometric data on presently single massive stars can potentially constrain the physics of massive binary evolution. Finally, we show that the high end of the mass distributions of runaway stars is very sensitive to the assumed black hole natal kicks and propose this as a potentially stringent test for the explosion mechanism. We also discuss companions remaining bound which can evolve into X-ray and gravitational wave sources.2019A&A...624A..66Rhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/624/A66CatalogResearchIsServedByTAP VizieR generic servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/624/A66https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/624/A66http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/624/A66https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/624/A66https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/624/A66http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/624/A66GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapdefaultJ/A+A/624/A66/table1Outcome of our model variationsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintFileNameName of the output file in subdirectory filesmeta.id;meta.filecharAssumpPhysical assumptionmeta.id;stat.fitcharParamParametermeta.noteValueValue of parameterstat.param<L>Average distance traveled from the ejection to CC for all massive companions ejectedpcpos.distanceint<Lrun>? Average distance traveled from the ejection to CC for massive runaways onlypcpos.distanceintnullable<Lwalk>Average distance traveled from the ejection to CC for massive walkaways onlypcpos.distanceint<v>Average velocitykm/sphys.veloc;stat.meanfloatvmedMedian velocitykm/sphys.veloc;stat.meanfloat<M2>Average mass for ejected main sequence companionssolMassphys.massfloat<M2run>? Average mass for ejected main sequence companions for runaways only,solMassphys.massfloatnullable<M2walk>Average mass for ejected main sequence companions for walkaways onlysolMassphys.massfloatRMS? Produced ratio R of walkaways to runaways for all massesstat.fit.paramfloatnullableR7.5? Produced ratio R of walkaways to runaways above 7.5Msunstat.fit.paramfloatnullableR15? Produced ratio R of walkaways to runaways above 15Msunstat.fit.paramfloatnullableMFraction of all the binaries simulated resulting in a mergerstat.fit.paramfloatDDisruption fraction among the non-merging binariesstat.fit.paramfloatf15RW? Fraction of runaways with masses larger than 15Msun%stat.fit.paramfloatnullablef15WA? Fraction of walkaways with masses larger than 15Msun%stat.fit.paramfloatnullable