Measurements of Physical Parameters of White Dwarfs: A Test of the Mass-Radius Relation

Abstract

We present a detailed spectroscopic and photometric analysis of 219 DA and DB white dwarfs for which trigonometric parallax measurements are available. Our aim is to compare the physical parameters derived from the spectroscopic and photometric techniques, and then to test the theoretical mass-radius relation for white dwarfs using these results. The agreement between spectroscopic and photometric parameters is found to be excellent, especially for effective temperatures, showing that our model atmospheres and fitting procedures provide an accurate, internally consistent analysis. Values of surface gravity and solid angle, obtained respectively from spectroscopy and photometry, are combined with parallax measurements in various ways to study the validity of the mass-radius relation from an empirical point of view. After a thorough examination of our results, we find that 73% and 92% of the white dwarfs are consistent within 1 and 2$\sigma$ confidence levels, respectively, with the predictions of the mass-radius relation, thus providing strong support to the theory of stellar degeneracy. Our analysis also allows us to identify 15 stars that are better interpreted in terms of unresolved double degenerate binaries. Atmospheric parameters for both components in these binary systems are obtained using a novel approach. We further identify a few white dwarfs that are possibly composed of an iron core rather than a carbon/oxygen core, since they are consistent with Fe-core evolutionary models.

64 pages, 20 figures, 1 table, accepted for publication in the Astrophysical Journal

References in corpus (14)

• Gaia Data Release 1. Summary of the astrometric, photometric, and survey properties
• The Chemical Composition of an Extrasolar Minor Planet
• New white dwarf stars in the Sloan Digital Sky Survey Data Release 10
• On the Spectral Evolution of Cool, Helium-Atmosphere White Dwarfs: Detailed Spectroscopic and Photometric Analysis of DZ Stars
• Relativistic deflection of background starlight measures the mass of a nearby white dwarf star
• The Solar Neighborhood. XXI. Parallax Results from the CTIOPI 0.9m Program: 20 New Members of the 25 Parsec White Dwarf Sample
• The Gaia DR1 Mass-Radius Relation for White Dwarfs
• The Solar Neighborhood. XXXIX. Parallax Results from the CTIOPI and NOFS Programs: 50 New Members of the 25 Parsec White Dwarf Sample
• The Solar Neighborhood. XIX. Discovery and Characterization of 33 New Nearby White Dwarf Systems
• The Solar Neighborhood. XX. Discovery and Characterization of 21 New Nearby White Dwarf Systems
• Analysis of cool DO-type white dwarfs from the Sloan Digital Sky Survey Data Release 10
• Comparison of Atmospheric Parameters Determined from Spectroscopy and Photometry for DA White Dwarfs in the Sloan Digital Sky Survey
• Trigonometric parallaxes of high velocity halo white dwarf candidates
• A New Merging Double Degenerate Binary in the Solar Neighborhood

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