Cyg X-3: can the compact object be a black hole?
| dc.creator | Ergma, Ene | |
| dc.creator | Yungelson, Lev R. | |
| dc.date | 1997-11-18 | |
| dc.date.accessioned | 2026-07-07T02:25:08Z | |
| dc.date.available | 2026-07-07T02:25:08Z | |
| dc.description | By means of population synthesis we find that the expected Galactic number of black holes with massive helium star companions is \sim 100 and depends on an assumed threshold for M_{pre-BH}. The overwhelming majority of these systems has orbital periods in excess of 10 hr, with a maximum at \sim 100 hr, while under the Illarionov & Sunyaev (1975) disk formation criteria for accretion from the strong stellar wind of Wolf-Rayet star disk accretion is possible only for orbital periods below \sim 10 hr. However, the number of such short-period systems is vanishingly small. If the accretor in Cyg X-3 is a 10 M_sun black hole, then the accretion rate will be super-Eddington. Super-Eddington accretion may be responsible for the formation of jets in Cyg X-3 and may also support an X-ray luminosity as high as \sim 10^{39} erg/s. From the orbital period distribution for neutron stars with massive helium companions we find that if during the common envelope phase a neutron star accretes at Eddington rate and spins-up to the equilibrium period, then in most systems it acts as a ``propeller'' and accretion from the WR star wind is impossible. For the model with two massive helium stars as an immediate progenitor of Cyg X-3, requirement of accomodation of two WR stars in the post-common-envelope orbit combined with severe mass loss by them prevents formation of BH+WR systems with orbital periods less than several days. | |
| dc.description | 8 pages, Latex, 2 figures, uses psfig.sty, to appear in Astronomy and Astrophysics | |
| dc.identifier | https://arxiv.org/abs/astro-ph/9711197 | |
| dc.identifier | http://arxiv.org/abs/astro-ph/9711197 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/11818 | |
| dc.subject | Astrophysics | |
| dc.title | Cyg X-3: can the compact object be a black hole? | |
| dc.type | text |