Extreme Warm Absorber variability in the Seyfert Galaxy Mrk 704

Abstract

In about half of Seyfert galaxies, the X-ray emission is absorbed by an optically thin, ionized medium, the so-called "Warm Absorber", whose origin and location is still a matter of debate. The aims of this paper is to put more constraints on the warm absorber by studying its variability. We analyzed the X-ray spectra of a Seyfert 1 galaxy, Mrk 704, which was observed twice, three years apart, by XMM-Newton. The spectra were well fitted with a two zones absorber, possibly covering only partially the source. The parameters of the absorbing matter - column density, ionization state, covering factor - changed significantly between the two observations. Possible explanations for the more ionized absorber are a torus wind (the source is a polar scattering one) or, in the partial covering scenario, an accretion disk wind. The less ionized absorber may be composed of orbiting clouds in the surroundings of the nucleus, similarly to what already found in other sources, most notably NGC 1365.

10 pages. Accepted for publication in Astronomy & Astrophysics

References in corpus (4)

• BAT X-ray Survey - III: X-ray Spectra and Statistical Properties
• The broad band spectrum and variability of NGC 4151 observed by BeppoSAX
• X-ray warm absorption and emission in the polar scattered Seyfert 1 galaxy MRK 704
• Extreme Warm Absorber variability in the Seyfert Galaxy Mrk 704

Cited by in corpus (9)

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• The distribution of the coronal temperature in Seyfert 1 galaxies
• The effect of UV/Soft X-ray excess emission on the warm absorber properties of Active Galactic Nuclei -- A case study of IRAS 13349+2438
• An X-ray variable absorber within the Broad Line Region in Fairall 51
• Long-term X-ray stability and UV variability of the ionized absorption in NGC 3783
• Extreme Warm Absorber variability in the Seyfert Galaxy Mrk 704
• X-ray warm absorber variability of the Seyfert Galaxy Arakelian 564