The helium white dwarf in two pulsars: too cool in PSR J0751+1807 and too hot in PSR J1012+5307?
| Autor: | E. Ergma, M. J. Sarna, J. Gerskevits-Antipova |
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| Rok vydání: | 2001 |
| Předmět: |
Physics
Hydrogen Astrophysics::High Energy Astrophysical Phenomena chemistry.chemical_element White dwarf Astronomy and Astrophysics Astrophysics Orbital period Binary pulsar Pulsar chemistry Space and Planetary Science Millisecond pulsar Astrophysics::Solar and Stellar Astrophysics Roche lobe Physics::Atomic Physics Astrophysics::Earth and Planetary Astrophysics Astrophysics::Galaxy Astrophysics Helium |
| Zdroj: | Monthly Notices of the Royal Astronomical Society. 321:71-76 |
| ISSN: | 1365-2966 0035-8711 |
| DOI: | 10.1046/j.1365-8711.2001.04000.x |
| Popis: | We discuss the cooling history of the low–mass, helium core white dwarfs in short orbital period millisecond pulsars PSR J0751+1807 and PSR J1012+5307. The revised cooling age estimated by Alberts et al. agrees with the age estimation for PSR J1012+5307, removing the discrepancy between the spin–down age and the cooling age. However, if we accept this model then the helium white dwarf in the binary pulsar system PSR J0751+1807 must be much hotter than is observed. We propose that this discrepancy may be resolved if, after detachment of the secondary star from its Roche lobe in PSR J0751+1807, the star loses its hydrogen envelope due to pulsar irradiation. When hydrogen burning stops, the white dwarf will cool down much more quickly than in the case of a thick hydrogen envelope with a hydrogen burning shell. We discuss several possibilities to explain different cooling histories of white dwarfs in both systems. |
| Databáze: | OpenAIRE |
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