Browsing by Author "Constantini, E."

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    Simultaneous XMM-Newton and HST-COS observation of 1H0419-577 The absorbing and emitting ionized gas
    Di Gesu, L.; Arav, Nahum; Borguet, B.; Detmers, R. G.; Ebrero, J.; Edmonds, Douglas; Kaastra, J. S.; Piconcelli, E.; Verbunt, F.; Constantini, E. (EDP Sciences, 2013-08)
    In this paper we analyze the X-ray, UV, and optical data of the Seyfert 1.5 galaxy 1H0419-577 with the aim of detecting and studying an ionized-gas outflow. The source was observed simultaneously in the X-rays with XMM-Newton and in the UV with HST-COS. Optical data were also acquired with the XMM-Newton Optical Monitor. We detected a thin, lowly ionized warm absorber (log xi approximate to 0.03, log N-H approximate to 19.9 cm(-2)) in the X-ray spectrum, which is consistent to be produced by the same outflow already detected in the UV. Provided the gas density estimated in the UV, the outflow is consistent to be located in the host galaxy at similar to kpc scale. Narrow emission lines were detected in the X-rays, in the UV and also in the optical spectrum. A single photoionized-gas model cannot account for all the narrow lines emission, indicating that the narrow line region is probably a stratified environment, differing in density and ionization. X-ray lines are unambiguously produced in a more highly ionized gas phase than the one emitting the UV lines. The analysis also suggests that the X-ray emitter may just be a deeper portion of the same gas layer producing the UV lines. Optical lines are probably produced in another disconnected gas system. The different ionization condition and the similar to pc scale location, suggested by the line width for the narrow lines emitters, are evidences against a connection between the warm absorber and the narrow line region in this source.
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    XMM-Newton RGS observation of the warm absorber in Mrk 279
    Ebrero, J.; Constantini, E.; Kaastra, J. S.; Detmers, R. G.; Arav, Nahum; Kriss, G. A.; Korista, K. T.; Steenbrugge, K. C. (EDP Sciences, 2010-09-10)
    Context. The Seyfert 1 galaxy Mrk 279 was observed by XMM-Newton in November 2005 on three consecutive orbits, showing significant short-scale variability (average soft band variation in flux ~20%). The source is known to host a two-component warm absorber with distinct ionisation states from a previous Chandra observation. Aims. We study the warm absorber in Mrk 279 and investigate any possible response to the short-term variations in the ionising flux and assess whether it has varied on a long-term timescale with respect to the Chandra observation. Methods. The XMM-Newton-RGS spectra of Mrk 279 were analysed in both the high- and low-flux states using the SPEX fitting package. Results. We find no significant changes in the warm absorber on either short timescales (~2 days) or longer ones (two and a half years), as the variations in the ionic column densities of the most relevant elements are below the 90% confidence level. The variations could still be present but are statistically undetected given the signal-to-noise ratio of the data. Starting from reasonable standard assumptions, we estimate the location of the absorbing gas, which is likely to be associated with the putative dusty torus rather than with the broad line region if the outflowing gas is moving at the escape velocity or greater.