Analysis of optical and ultraviolet spectroscopy of the DAZ white dwarf G74-7

被引：6

作者：

Billeres, M

Wesemael, F

Bergeron, P

Beauchamp, A

机构：

[1] LOCKHEED MARTIN CANADA, MONTREAL, PQ H4P 1K6, CANADA

[2] CAE ELECTRON LTEE, ST LAURENT, PQ H4L 4X4, CANADA

来源：

ASTROPHYSICAL JOURNAL | 1997年 / 488卷 / 01期

关键词：

stars; individual; (G74-7); white dwarfs; ultraviolet;

D O I：

10.1086/304689

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

We present new spectroscopic and photometric observations of the cool DAZ white dwarf G74-7. These data are combined with archival HST Faint Object Spectrograph data covering the range 1700-3200 Angstrom, allowing estimates of the Ca, Mg, and Fe abundances in this object. Our analysis suggests that G74-7 is a hydrogen-rich star of normal gravity, with T-eff = 7320 K and the following photospheric abundances: log(Ca/H)= -8.8 +/- 0.2, log(Mg/H) = -8.1 +/- 0.3, and an upper limit to log(Fe/H) less than or similar to -5. These new results are considered within the framework of current models proposed to explain the presence of heavy elements in the high-gravity photospheres of white dwarf stars.

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页码：368 / 374

页数：7

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