Heavy Element Abundance Patterns in Hot White Dwarfs from a Survey of the FUSE Archive
conference contributionposted on 2016-12-07, 15:28 authored by M. A. Barstow, S. L. Casewell, J. B. Holberg, J. K. Barstow
We present a series of systematic abundance measurements for 89 hot DA white dwarfs drawn from the FUSE observation archive. These stars span the temperature range ≈ 20000-70000K, and form the largest sample to-date, exceeding our earlier study, based mainly on IUE and HST data, by a factor three. Using the heavy element blanketed non-LTE stellar atmosphere calculations from this previous work, we are able to measure the abundances of carbon, silicon, phosphorus and sulphur and examine how they change as the stars cool. We are able to establish the broad range of abundances seen in a given temperature range and establish the incidence of stars which, like HZ43, appear to (surprisingly) be completely devoid of any material other than H in their atmospheres. As a result we can begin to identify stars with peculiar abundances in this temperature range and determine whether or not these objects might be accreting planetary debris, as has been inferred for many cooler objects.
MAB and JKB acknowledge the support of the Science and Technology Facilities Council. SLC is supported by the University of Leicester. JBH acknowledges a visiting professorship from the University of Leicester.
Citation18th European White Dwarf Workshop, 2013, 469, pp. 121-126 (6)
Author affiliation/Organisation/COLLEGE OF SCIENCE AND ENGINEERING/Department of Physics and Astronomy
Source18th European White Dwarf Workshop, EUROWD12, Pedagog Univ Cracow, Krakow, POLAND
- AM (Accepted Manuscript)