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

S. P. Preval; M. A. Barstow

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

S. P. Preval, M. A. Barstow

Physics

Research output: Chapter in Book/Report/Conference proceeding › Conference contribution book

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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 language	English
Title of host publication	20th European Workshop on White Dwarfs (EuroWD16)
Editors	Pier-Emmanuel Tremblay, Boris Gänsicke, Tom Marsh
Place of Publication	San Francisco
Pages	195-200
Number of pages	6
Volume	509
Publication status	Published - 1 Mar 2017
Event	20th European Workshop on White Dwarfs - University of Warwick, Coventry, United Kingdom Duration: 25 Jul 2016 → 29 Jul 2016 http://www2.warwick.ac.uk/fac/sci/physics/research/astro/research/meetings/eurowd16/

Publication series

Name	Astronomical Society of the Pacific Conference Series
Publisher	Astronomical Society of the Pacific
Volume	509

Conference

Conference	20th European Workshop on White Dwarfs
Abbreviated title	EuroWD
Country/Territory	United Kingdom
City	Coventry
Period	25/07/16 → 29/07/16
Internet address	http://www2.warwick.ac.uk/fac/sci/physics/research/astro/research/meetings/eurowd16/

Keywords

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

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Preval-Barstow-EuroWD-2016-Understanding-the-spectrum-of-the-very-hot-DA-white-dwarfAccepted author manuscript, 101 KB

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title = "Understanding the spectrum of the very hot DA white dwarf PG 0948+534",

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. ",

keywords = "white dwarf stars, PG0948+534, uv spectrum, circumstellar absorption, thermodynamic equilibrium model, gravity",

author = "Preval, {S. P.} and Barstow, {M. A.}",

year = "2017",

month = mar,

day = "1",

language = "English",

isbn = "9781583819029",

volume = "509",

series = "Astronomical Society of the Pacific Conference Series",

publisher = "Astronomical Society of the Pacific",

pages = "195--200",

editor = "Pier-Emmanuel Tremblay and Boris G{\"a}nsicke and Tom Marsh",

booktitle = "20th European Workshop on White Dwarfs (EuroWD16)",

note = "20th European Workshop on White Dwarfs, EuroWD ; Conference date: 25-07-2016 Through 29-07-2016",

url = "http://www2.warwick.ac.uk/fac/sci/physics/research/astro/research/meetings/eurowd16/",

}

Preval, SP & Barstow, MA 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, Astronomical Society of the Pacific Conference Series, vol. 509, San Francisco, pp. 195-200, 20th European Workshop on White Dwarfs, Coventry, United Kingdom, 25/07/16.

Understanding the spectrum of the very hot DA white dwarf PG 0948+534. / Preval, S. P.; Barstow, M. A.
20th European Workshop on White Dwarfs (EuroWD16). ed. / Pier-Emmanuel Tremblay; Boris Gänsicke; Tom Marsh. Vol. 509 San Francisco, 2017. p. 195-200 (Astronomical Society of the Pacific Conference Series; Vol. 509).

Research output: Chapter in Book/Report/Conference proceeding › Conference contribution book

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T1 - Understanding the spectrum of the very hot DA white dwarf PG 0948+534

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AU - Barstow, M. A.

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N2 - 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.

AB - 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.

KW - white dwarf stars

KW - PG0948+534

KW - uv spectrum

KW - circumstellar absorption

KW - thermodynamic equilibrium model

KW - gravity

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SN - 9781583819029

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BT - 20th European Workshop on White Dwarfs (EuroWD16)

A2 - Tremblay, Pier-Emmanuel

A2 - Gänsicke, Boris

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CY - San Francisco

T2 - 20th European Workshop on White Dwarfs

Y2 - 25 July 2016 through 29 July 2016

ER -

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

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