ROSAT OBSERVATIONS OF X-RAY-SELECTED ACTIVE GALACTIC NUCLEI

被引:5
|
作者
THOMPSON, RJ [1 ]
PUCHNAREWICZ, EM [1 ]
CORDOVA, FA [1 ]
MASON, KO [1 ]
机构
[1] UNIV LONDON UNIV COLL,MULLARD SPACE SCI LAB,DORKING,SURREY,ENGLAND
来源
ASTROPHYSICAL JOURNAL | 1994年 / 420卷 / 01期
关键词
GALAXIES; ACTIVE; NUCLEI; X-RAYS;
D O I
10.1086/173546
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
We have observed a sample of six optically faint, X-ray-selected active galactic nuclei with the ROSAT Position Sensitive Proportional Counter (PSPC). These objects represent a sample of soft and hard spectrum sources; all were observed previously with the Einstein X-Ray Observatory. Included in this sample is E0132.8 - 4111, whose soft X-ray and ultraviolet flux distributions bear a striking resemblance to that of Mrk 841, but whose relative hard X-ray emission is much less than that of Mrk 841. The spectra are all fitted satisfactorily with single power-law models and their spectral indices (with one exception) agree with those estimated from the Einstein IPC observations. Tests of short-term variability are carried out, with all sources showing constant count rates over the period of their ROSAT observations. Some sources do, however, show significant changes in count rate when compared to previous Einstein data taken a decade earlier.
引用
收藏
页码:136 / 142
页数:7
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