Compact Remnant Research Articles

The velocity-mass correlation of the O-type stars - Model results

This paper presents new model results describing the evolution of massive close binaries from their initial ZAMS to post-supernova stages. Unlike the previous conservative study by Stone (Astrophys. J. 232, 520 (1979) (Paper II)), these results allow explicitly for mass loss from the binary system occurring during the core hydrogen- and helium-burning stages of the primary binary star as well as during the Roche lobe overflow. Because of uncertainties in these rates, model results are given for several reasonable choices for these rates. All of the models consistently predict an increasing relation between the peculiar space velocities and masses for runaway OB stars which agrees well with the observed correlations discussed in Stone (Astron. J. 86, 544 (1981) (Paper III)) and also predict a lower limit at Mroughly-equal11M/sub sun/ for the masses of runaway stars, in agreement with the observational limit found by A. Blaauw (Bull. Astron. Inst. Neth. 15, 265, 1961), both of which support the binary-supernova scenario described by van den Heuvel and Heise for the origin of runaway stars. These models also predict that the more massive O stars will produce correspondingly more massive compact remnants, and that most binaries experiencing supernova-induced kick velocities of magnitude V/submore » k/> or approx. =300 km s/sup -1/ will disrupt following the explosions. The best estimate for this velocity as established from pulsar observations is V/sub k/roughly-equal150 km s/sup -1/, in which case probably only 15% if these binaries will be disrupted by the supernova explosions, and therefore, almost all runaway stars should have either neutron star or black hole companions.« less

Supernovae — Birthplace of Pulsars?

Recent developments in the theory of the light from supernovae indicate that while Type II supernovae probably involve the explosion of a massive star with an extended envelope, Type I supernovae may involve the total thermonuclear disruption of a white dwarf. The energy release in a Type II supernova is presumably related to the contraction of the core to a neutron star and pulsar formation is likely. The hypothesis that Type II supernovae leave pulsars while Type I supernovae do not leave compact remnants is shown to be consistent with the available information on X-ray sources containing neutron stars, young supernova remnants, and the distribution of pulsars in the galaxy. Some pulsars are probably formed in the explosion of a massive star that has lost its envelope. These events may not be accompanied by a bright supernova display.

Monographs on Astronomical Subjects 6: Cosmic X-Ray Astronomy

D J Adams 1980 Bristol: Adam Hilger x + 150 pp price £13.50 (IOP members' price £10.15) Aimed both at nonspecialists and those entering the field, the book begins with an outline of the practical techniques of x-ray astronomy and a useful summary of the relevant theoretical arguments. The remaining chapters describe the interpretation of x-ray data from compact galactic sources, supernova remnants and extragalactic sources.

Evolution of massive common envelope binaries and mass loss

A way of treatment of evolution of common envelope binaries based only on the laws of conservation of energy and angular momentum is suggested. It is shown that the final configuration depends on masses of components and initial period of the system, and on parameters describing friction in the envelope, and mass loss by the system. Possible final stages for massive binaries are either a Thorne-Zytkow type object for initially close binaries or a Wolf-Rayet star in pair with a relativistic compact remnant for wider ones. In the course of disruption of the latter system with orbital periods up to several hours very high space velocity (up to 500 km/s) pulsars can arise.

Coincidence of compact supernova remnants with three COS-B γ-ray sources

POSITIONAL coincidences and a ‘near miss’ of four small-diameter supernova remnants (SNR) with three of the 11 unidentified COS-B γ-ray sources1 are reported here. I argue that it is unlikely that all four SNR–γ-ray source associations are accidental, and that their compactness probably indicates that their ages are not greater than about 104 yr. Although these four SNR are not associated with known pulsars, the radio emission2–4 in each case is centrally peaked which admits the possibility of a central pulsar. If these associations are physical the γ rays could originate from a remnant pulsar or could be due to cosmic ray interactions in the vicinity of the remnant5. The only two previously identified6,7 and confirmed8 γ-ray sources are the Crab pulsar and the Vela pulsar ,both of which are associated with young (≲ 2×4 yr) SNR. In these two cases the γ-ray emission is predominantly pulsed and therefore comes directly from the remnant short-period pulsars.

On the nature of the globular cluster X-ray sources

view Abstract Citations (129) References (34) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS On the nature of the globular cluster X-ray sources. Silk, J. ; Arons, J. Abstract It is suggested that the globular cluster X-ray sources can be interpreted in terms of mass shed by evolving postmain-sequence stars in the central regions of the globular cluster and accreting onto a massive (approximately 100-1000 solar masses) central black hole. Tentative indications that support this hypothesis include the high central escape velocities and the distribution of metallicities among the four globular clusters containing luminous X-ray sources. We argue that these X-ray sources cannot be explained as a consequence of the close capture of a nuclear burning star by a compact stellar remnant. Publication: The Astrophysical Journal Pub Date: September 1975 DOI: 10.1086/181914 Bibcode: 1975ApJ...200L.131S Keywords: Black Holes (Astronomy); Globular Clusters; Stellar Evolution; X Ray Sources; Capture Effect; Nuclear Reactions; Stellar Mass; Astrophysics full text sources ADS |