A longer XMM-Newton look at I Zwicky 1: physical conditions and variability of the ionised absorbers

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dc.creatorCostantini, E.
dc.creatorGallo, L. C.
dc.creatorBrandt, W. N.
dc.creatorFabian, A. C.
dc.creatorBoller, Th.
dc.date2007-02-21
dc.date.accessioned2026-07-07T11:00:54Z
dc.date.available2026-07-07T11:00:54Z
dc.descriptionWe present a spectral analysis of the narrow-line Seyfert 1 galaxy I Zwicky 1, focusing on the characteristics of the ionised absorbers as observed with XMM-Newton in 2005. The soft X-ray spectrum shows absorption by two components of ionised gas with a similar column density (N_H~10^{21} cm^{-2}) and ionisation parameters logξ~0 and 2.5. Comparing this observation with a 2002 XMM-Newton data set, we see a clear anti-correlation between the X-ray ionisation parameter xi_X and the 0.1-10 keV luminosity. Viable explanations for this effect include transient clouds or filaments crossing the line of sight in a complex geometry or a gas observed in non-equilibrium. The outflow velocity of the X-ray low-ionisation absorber is consistent with the outflow of the UV absorber detected in a past Hubble Space Telescope observation. In addition, the ionic column densities of CIV and NV derived from the X-ray model are consistent with the UV values. This suggests that the low-ionisation outflowing gas may survive for many years, despite large changes in flux, and that there is a tight connection between the X-ray and UV absorbers that can only be confirmed with a simultaneous UV and X-ray observation.
dc.description9 pages, 9 figures. Accepted for publication in MNRAS
dc.identifierhttps://arxiv.org/abs/astro-ph/0702553
dc.identifierhttp://arxiv.org/abs/astro-ph/0702553
dc.identifierMon.Not.Roy.Astron.Soc.378:873-880,2007
dc.identifierdoi:10.1111/j.1365-2966.2007.11646.x
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/187800
dc.subjectAstrophysics
dc.titleA longer XMM-Newton look at I Zwicky 1: physical conditions and variability of the ionised absorbers
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