Understanding the spectrum of the very hot DA white dwarf PG 0948+534

S. P. Preval, M. A. Barstow

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Abstract

PG 0948+534 is currently one of the hottest DA white dwarf stars, and is also one of the most mysterious. Attempts to model the sharp, deep absorption features of this star have been unsuccessful. In these proceedings we describe our analysis of PG 0948+534. We perform a line survey of the UV spectrum of PG 0948+534, making detections of 300+ absorption features, and identifying four distinct velocity regimes. We find evidence of circumstellar absorption in the profiles of C IV and Si IV. Using non-local thermodynamic equilibrium model atmospheres, we are able to correctly model the absorption features of the star, providing abundance measurements for C, N, O, and Si for PG 0948+534 for the first time. We also revise the effective temperature and gravity for this star using models including these new abundances.
Original languageEnglish
Title of host publication20th European Workshop on White Dwarfs (EuroWD16)
EditorsPier-Emmanuel Tremblay, Boris Gänsicke, Tom Marsh
Place of PublicationSan Francisco
Pages195-200
Number of pages6
Volume509
Publication statusPublished - 1 Mar 2017
Event20th European Workshop on White Dwarfs - University of Warwick, Coventry, United Kingdom
Duration: 25 Jul 201629 Jul 2016
http://www2.warwick.ac.uk/fac/sci/physics/research/astro/research/meetings/eurowd16/

Publication series

NameAstronomical Society of the Pacific Conference Series
PublisherAstronomical Society of the Pacific
Volume509

Conference

Conference20th European Workshop on White Dwarfs
Abbreviated titleEuroWD
CountryUnited Kingdom
CityCoventry
Period25/07/1629/07/16
Internet address

Keywords

  • white dwarf stars
  • PG0948+534
  • uv spectrum
  • circumstellar absorption
  • thermodynamic equilibrium model
  • gravity

Cite this

Preval, S. P., & Barstow, M. A. (2017). Understanding the spectrum of the very hot DA white dwarf PG 0948+534. In P-E. Tremblay, B. Gänsicke, & T. Marsh (Eds.), 20th European Workshop on White Dwarfs (EuroWD16) (Vol. 509, pp. 195-200). (Astronomical Society of the Pacific Conference Series; Vol. 509)..