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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…
Between July 2012 and February 2013, NuSTAR and XMM-Newton performed four long-look joint obser- vations of the type 1.8 Seyfert, NGC 1365. We have analyzed the variable absorption seen in these observations in order to characterize the…
We present the 0.5 - 50 keV Suzaku broad-band X-ray spectral study of the Compton-thick AGN in NGC 5135. The Suzaku observation provides the first detection of NGC 5135 above 10 keV that allowed us, for the first time, to estimate the…
Type 2 active galactic nuclei (AGN) show signatures of accretion onto a supermassive black hole through strong, high-ionization, narrow emission lines extended on scales of 100s to 1000s of parsecs, but they lack the broad emission lines…
We report on observations of the narrow line Seyfert galaxy NGC 5506 with the Rossi X-ray TIming Explorer. The observations cover a time interval of ~1000 days during which the source showed strong flux and spectral variability. The…
An-energy dependent variation of the X-ray emission from the archetypical "Compton-thick'' Seyfert 2 galaxy NGC1068 has been observed between two BeppoSAX observations, performed one year apart. This variation (at the 2.6 sigma level) is…
Mid-infrared (MIR) spectra observed with Gemini/Michelle were used to study the nuclear region of the Compton-thick Seyfert 2 (Sy 2) galaxy Mrk 3 at a spatial resolution of $\sim$200 pc. No polycyclic aromatic hydrocarbons (PAHs) emission…
Winds outflowing from Active Galactic Nuclei (AGNs) may carry significant amount of mass and energy out to their host galaxies. In this paper we report the detection of a sub-relativistic outflow observed in the Narrow Line Seyfert 1 Galaxy…
We present an observation of XMM-Newton that unambiguously reveals the ``Seyfert 2'' nature of the Broad Line Radio Galaxy 3C 445. For the first time the soft excess of this source has been resolved. It consists of unobscured scattered…
We report on the XMM-Newton observation of the bright Seyfert 1 galaxy, MCG+8-11-11. Data from the EPIC/p-n camera, the Reflection Gratings Spectrometers (RGS) and the Optical Monitor (OM) have been analyzed. The p-n spectrum is well fitted…
We present the X-ray analysis of the most luminous obscured active galactic nuclei (AGN) inside local ultraluminous infrared galaxies (ULIRGs). Our sample consists of ten sources, harbouring AGN components with estimated luminosity in…
We present results on the hard X-ray emission of NGC 5506, the brightest narrow line Seyfert 1 galaxy above 20 keV. All the recent observations by INTEGRAL, Swift and Suzaku have been analysed and spectral analysis during nine separated…
We study the X-ray spectra of a sample of 19 obscured, optically-selected Seyfert galaxies (Sy 1.8, 1.9 and 2) in the local universe ($d \leq 175$~Mpc), drawn from the CfA Seyfert sample. Our analysis is driven by the high sensitivity of…
We present results on the Seyfert 2 galaxy NGC4388 in the Virgo cluster observed with ASCA during its PV phase. The 0.5-10 keV X-ray spectrum consists of multiple components; (1) a continuum component heavily absorbed by a column density NH…
We present mid infrared (Mid-IR) spectra of the Compton-thick Seyfert 2 galaxy NGC\,3281, obtained with the Thermal-Region Camera Spectrograph (T-ReCS) at the Gemini South telescope. The spectra present a very deep silicate absorption at…
Active galactic nuclei (AGN) showing dramatic spectral and flux variations, either due to changes in the accretion rate (changing-state, CS-AGN) of the supermassive black hole or in the line-of-sight column density (changing-obscuration,…
We report the discovery of the Narrow-Line Seyfert 1 galaxy Mkn 335 in an extremely low X-ray state. A comparison of Swift observations obtained in May and June/July 2007 with all previous X-ray observations between 1971 to 2006 show the…
A large population of heavily obscured, Compton Thick AGNs is predicted by models of galaxy formation, models of Cosmic X-ray Background and by the ``relic'' super-massive black-hole mass function measured from local bulges. However, so far…
We report the discovery of a ultraluminous X-ray source (ULX; CXO J133815.6+043255) in NGC 5252. This ULX is an off-nuclear point-source, which is 22$^{\prime\prime}$ away from the center of NGC 5252, and has an X-ray luminosity of 1.5…
Swift has initiated a new era of understanding the extremes of active galactic nuclei (AGN) variability, their drivers and underlying physics. This is based on its rapid response, high sensitivity, good spatial resolution, and its ability…