ROSAT PSPC OBSERVATIONS OF THE SEYFERT-1 GALAXIES ARK-564, NGC-985, KAZ-163, MRK-79 AND RX-J2256.6+0525

被引：68

作者：

BRANDT, WN ^{[1
]}

FABIAN, AC ^{[1
]}

NANDRA, K ^{[1
]}

REYNOLDS, CS ^{[1
]}

BRINKMANN, W ^{[1
]}

机构：

[1] MAX PLANCK INST EXTRATERR PHYS,D-85478 GARCHING,GERMANY

来源：

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY | 1994年 / 271卷 / 04期

关键词：

GALAXIES; INDIVIDUAL; ARK; 564; NGC; 985; KAZ; 163; MRK; 79; RX J2256.6+0525; X-RAYS;

D O I：

10.1093/mnras/271.4.958

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

We present spatial, temporal and spectral analyses of ROSAT Position Sensitive Proportional Counter (PSPC) observations of the Seyfert 1 galaxies Ark 564, NGC 985, Kaz 163, Mrk 79 and RX 52256.6 + 0525. Ark 564 is a powerful narrow-line Seyfert 1 with strong Fe II emission. Several similar narrow-line Seyfert 1 galaxies have recently been found to have remarkably steep soft X-ray continua as well as rapid X-ray variability. We find that Ark 564 also has a very steep (Gamma > 3) 0.1-2.5 keV spectrum and varies by similar to 20 per cent in 1500 s. We examine models for Ark 564 in light of both its X-ray and optical characteristics, and suggest a possible connection between the steep X-ray spectra of narrow-line Seyfert I galaxies and their narrow lines. NGC 985 has a large soft excess, a warm absorber, or both. The three other Seyferts have systematically steeper spectra than are typically observed for Seyferts in higher energy Ginga data, indicating that they also harbour further spectral complexity. Kaz 163 shows similar to 45 per cent intensity variability in the 0.1-2.5 keV band, and Mrk 79 shows evidence for variability as well.

引用

页码：958 / 966

页数：9