THE INITIAL-FINAL MASS RELATION AMONG WHITE DWARFS IN WIDE BINARIES

Journal Article · Mon Feb 20 04:00:00 EST 2012 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/746/2/144· OSTI ID:22011736

Zhao, J K; Oswalt, T D ^[1]; Willson, L A; Wang, Q ^[2]; Zhao, G ^[3]

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1. Physics and Space Science Department, Florida Institute of Technology, Melbourne, FL 32901 (United States)
2. Department of Physics and Astronomy, Iowa State University, Ames, IA 50010 (United States)
3. Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China)

We present the initial-final mass relation derived from 10 white dwarfs in wide binaries that consist of a main-sequence star and a white dwarf. The temperature and gravity of each white dwarf were measured by fitting theoretical model atmospheres to the observed spectrum using a {chi}{sup 2} fitting algorithm. The cooling time and mass were obtained using theoretical cooling tracks. The total age of each binary was estimated from the chromospheric activity of its main-sequence component to an uncertainty of about 0.17 dex in log t. The difference between the total age and white dwarf cooling time is taken as the main-sequence lifetime of each white dwarf. The initial mass of each white dwarf was then determined using stellar evolution tracks with a corresponding metallicity derived from spectra of their main-sequence companions, thus yielding the initial-final mass relation. Most of the initial masses of the white dwarf components are between 1 and 2 M{sub Sun }. Our results suggest a correlation between the metallicity of a white dwarf's progenitor and the amount of post-main-sequence mass loss it experiences-at least among progenitors with masses in the range of 1-2 M{sub Sun }. A comparison of our observations to theoretical models suggests that low-mass stars preferentially lose mass on the red giant branch.

• OSTI ID: 22011736
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 746; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ALGORITHMS
GRAVITATION
MAIN SEQUENCE STARS
MASS
SPECTRA
STAR EVOLUTION
STELLAR ATMOSPHERES
WHITE DWARF STARS