Accreting, Isolated Neutron Stars. III. Preheating of Infalling Gas and Cometary H II Regions

Abstract

view Abstract Citations (41) References (40) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Accreting, Isolated Neutron Stars. III. Preheating of Infalling Gas and Cometary H II Regions Blaes, Omer ; Warren, Orlando ; Madau, Piero Abstract Nearby, isolated, old neutron stars (IONSs) accreting interstellar material might be detectable as sources of UV and soft X-ray radiation. We investigate the interaction between this radiation field and the surrounding medium, assumed to consist of purely hydrogen and helium. This interaction results in a cometary H II region around the star which we model in detail by including all the relevant time-dependent ionization, recombination, heating, and cooling processes. We find that preheating of the ambient gas to temperatures higher than 104 K may significantly quench the accretion rate onto these neutron stars, thereby reducing the IONS number counts in the EUV and soft X-ray bands predicted by previous investigations. However, the reprocessing of hard radiation by the surrounding H II regions may enhance the detectability of IONSs at optical wavelengths. Searches for nearby accreting IONSs are currently being undertaken. Publication: The Astrophysical Journal Pub Date: November 1995 DOI: 10.1086/176488 Bibcode: 1995ApJ...454..370B Keywords: ACCRETION; ACCRETION DISKS; ISM: H II REGIONS; STARS: NEUTRON; ULTRAVIOLET: STARS; X-RAYS: STARS full text sources ADS | data products SIMBAD (1)