Suppression of luminosity and mass–radius relation of highly magnetized white dwarfs
Autor: | Banibrata Mukhopadhyay, Christopher A. Tout, Abhay Gupta |
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Přispěvatelé: | Tout, Christopher [0000-0002-1556-9449], Apollo - University of Cambridge Repository |
Rok vydání: | 2020 |
Předmět: |
Opacity
Astrophysics::High Energy Astrophysical Phenomena Solar luminosity FOS: Physical sciences radiation mechanisms: general Astrophysics::Cosmology and Extragalactic Astrophysics Astrophysics magnetic fields Astrophysics::Solar and Stellar Astrophysics Chandrasekhar limit Conservation of mass Solar and Stellar Astrophysics (astro-ph.SR) equation of state Astrophysics::Galaxy Astrophysics white dwarfs High Energy Astrophysical Phenomena (astro-ph.HE) Physics Solar mass Inner core opacity White dwarf Astronomy and Astrophysics stars: luminosity function mass function Magnetic field Astrophysics - Solar and Stellar Astrophysics Space and Planetary Science Astrophysics::Earth and Planetary Astrophysics Astrophysics - High Energy Astrophysical Phenomena |
Zdroj: | Monthly Notices of the Royal Astronomical Society. 496:894-902 |
ISSN: | 1365-2966 0035-8711 |
Popis: | We explore the luminosity L of magnetized white dwarfs and its effect on the mass-radius relation. We self-consistently obtain the interface between the electron degenerate gas dominated inner core and the outer ideal gas surface layer or envelope by incorporating both the components of gas throughout the model white dwarf. This is obtained by solving the set of magnetostatic equilibrium, photon diffusion and mass conservation equations in the Newtonian framework, for different sets of luminosity and magnetic field. We appropriately use magnetic opacity, instead of Kramer's opacity, wherever required. We show that the Chandrasekhar-limit is retained, even at high luminosity upto about 10^{-2} solar luminosity but without magnetic field, if the temperature is set constant inside the interface. However there is an increased mass for large-radius white dwarfs, an effect of photon diffusion. Nevertheless, in the presence of strong magnetic fields, with central strength of about 10^{14} G, super-Chandrasekhar white dwarfs, with masses of about 1.9 solar mass, are obtained even when the temperature inside the interface is kept constant. Most interestingly, small-radius magnetic white dwarfs remain super-Chandrasekhar even if their luminosity decreases to as low as about 10^{-20} solar luminosity. However, their large-radius counterparts in the same mass-radius relation merge with Chandrasekhar's result at low L. Hence, we argue for the possibility of highly magnetized, low luminous super-Chandrasekhar mass white dwarfs which, owing to their faintness, can be practically hidden. 11 pages including 2 in Appendix, 8 figures including 3 in Appendix (total 9 eps files) and 3 tables (change in ordering figures w.r.to previous version); Accepted for publication in MNRAS |
Databáze: | OpenAIRE |
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