TY - JOUR
T1 - A longer XMM-Newton look at i Zwicky 1
T2 - Physical conditions and variability of the ionized absorbers
AU - Costantini, E.
AU - Gallo, L. C.
AU - Brandt, W. N.
AU - Fabian, A. C.
AU - Boller, Th
PY - 2007/7
Y1 - 2007/7
N2 - We present a spectral analysis of the narrow-line Seyfert 1 galaxy I Zwicky 1, focusing on the characteristics of the ionized absorbers as observed with XMM-Newton in 2005. The soft X-ray spectrum shows absorption by two components of ionized gas with a similar column density and ionization parameters and 2.5. Comparing this observation with a 2002 XMM-Newton data set, we see a clear anticorrelation between the X-ray ionization parameter 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-ionization absorber is consistent with the outflow of the ultraviolet (UV) absorber detected in a past Hubble Space Telescope observation. In addition, the ionic column densities of C iv and N v derived from the X-ray model are consistent with the UV values. This suggests that the low-ionization 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.
AB - We present a spectral analysis of the narrow-line Seyfert 1 galaxy I Zwicky 1, focusing on the characteristics of the ionized absorbers as observed with XMM-Newton in 2005. The soft X-ray spectrum shows absorption by two components of ionized gas with a similar column density and ionization parameters and 2.5. Comparing this observation with a 2002 XMM-Newton data set, we see a clear anticorrelation between the X-ray ionization parameter 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-ionization absorber is consistent with the outflow of the ultraviolet (UV) absorber detected in a past Hubble Space Telescope observation. In addition, the ionic column densities of C iv and N v derived from the X-ray model are consistent with the UV values. This suggests that the low-ionization 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.
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U2 - 10.1111/j.1365-2966.2007.11646.x
DO - 10.1111/j.1365-2966.2007.11646.x
M3 - Article
AN - SCOPUS:34250618578
SN - 0035-8711
VL - 378
SP - 873
EP - 880
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 3
ER -