ABSTRACT Wepresentspatial,temporalandspectralanalysesofROSATPositionSensitiveProportionalCounter(PSPC)observationsoftheSeyfert1galaxiesArk564,NGC985, Kaz163,Mrk79andRXJ2256:6+0525.Ark564isapowerfulnarrow-lineSeyfert
نویسندگان
چکیده
We present spatial, temporal and spectral analyses of ROSAT Position Sensitive Pro-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 nd that Ark 564 also has a very steep ((> 3) 0.1{2.5 keV spectrum and varies by 20 per cent in 1 500 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 1 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 45 per cent intensity variability in the 0.1{2.5 keV band, and Mrk 79 shows evidence for variability as well.
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