AN ARCHIVAL STUDY OF HUBBLE-SPACE-TELESCOPE OBSERVATIONS OF HERCULES X-1/HZ HERCULIS

被引:40
作者
CHENG, FH
VRTILEK, SD
RAYMOND, JC
机构
[1] SHANGHAI JIAO TONG UNIV,INST SPACE SCI,SHANGHAI 200030,PEOPLES R CHINA
[2] HARVARD SMITHSONIAN CTR ASTROPHYS,CAMBRIDGE,MA 02138
关键词
ACCRETION; ACCRETION DISKS; BINARIES; ECLIPSING; PULSARS; INDIVIDUAL (HERCULES X-L)-STARS; INDIVIDUAL (HERCULES X-1); X-RAYS; STARS;
D O I
10.1086/176351
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
We present an archival study of observations of Her X-1/HZ Her obtained by the Faint Object Spectrograph (FOS) on the Hubble Space Telescope (HST). The optical light curve of HZ Her has previously been modeled as an X-ray heated star (e.g., Bahcall & Bahcall 1972) or an X-ray heated star plus disk (e.g., Gerend & Boynton 1976; Howarth & Wilson 1983a, b). We have utilized the system geometry as modeled by Howarth & Wilson (1983a) and have added blackbody components to our X-ray heating code to allow us to match better the observed slope of the HST/FOS spectrum and the strength of the Balmer jump. By fitting our model to the HST/FOS spectrum obtained at total eclipse (binary phase 0.0), we determine the mean temperature of the unheated star surface to be 8100+/-240 K, consistent with an A7 star. From the best-fit model to the HST/FOS spectrum near the binary phase 0.5, we determine a mass transfer rate M = (6.5+/-0.9) x 10(-9) M(circle dot) yr(-1).
引用
收藏
页码:825 / 832
页数:8
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