Related papers: Decoupling absorption and continuum variability in…
We present echelle observations of the intrinsic UV absorption lines in the Seyfert galaxy NGC 4151, which were obtained with the Space Telescope Imaging Spectrograph (STIS) on the Hubble Space Telescope on 1999 July 19. The UV continuum…
We report on the results of detailed X-ray spectroscopy of the Fe K region in the Seyfert 1 galaxy NGC 3783 from five ~170 ks observations with the Chandra high energy gratings. Monitoring was conducted over an interval of ~125 days in…
We present an analysis of the extreme obscuration variability observed during an XMM-Newton 5-days continuous monitoring of the AGN in NGC 1365. The source was in a reflection-dominated state in the first ~1.5 days, then a strong increase…
[Abridged]We report on the broadband X-ray properties of a complete sample of absorbed Seyfert galaxies hard X-ray selected with INTEGRAL. The sample is composed of 33 sources: 15 are newly discovered above 20 keV while 18 are already known…
We present Chandra imaging and spectral observations of Seyfert 2 galaxy NGC 4388. Three extended X-ray structures around the nucleus on kpc scale are well imaged, allowing an in-depth spatially resolved study. Both the extended hard…
We report on a three-year program of coordinated X-ray and optical monitoring of the Narrow-Line Seyfert 1 galaxy NGC 4051. The rapid continuum variations observed in the X-ray spectra are not detected in the optical, although the X-ray and…
The Swift/BAT nine-month survey observed 153 AGN, all with ultra-hard X-ray BAT fluxes in excess of 10^-11 erg cm^-2 s^-1 and an average redshift of 0.03. Among them, four of the most luminous BAT AGN (44.73 < Log L(BAT) < 45.31) were…
A Suzaku X-ray observation of NGC 4051 taken during 2005 Nov reveals line emission at 5.44 keV in the rest-frame of the galaxy which does not have an obvious origin in known rest-frame atomic transitions. The improvement to the fit…
We report the serendipitous discovery of a transient X-ray source, Suzaku J1305$-$4930, $\sim$3 kpc southwest of the nucleus of the Seyfert 2 galaxy NGC 4945. Among the seven Suzaku observations of NGC 4945 from 2005 to 2011, Suzaku…
We present the analysis of an XMM observation of the Seyfert galaxy NGC 2992. The source was found in its highest level of X-ray activity yet detected, a factor $\sim 23.5$ higher in 2--10 keV flux than the historical minimum. NGC 2992 is…
MCG-6-30-15, at a distance of 37 Mpc (z=0.008), is the archetypical Seyfert 1 galaxy showing very broad Fe K$\alpha$ emission. We present results from a joint NuSTAR and XMM-Newton observational campaign that, for the first time, allows a…
NGC 1275 is a gamma-ray-emitting radio galaxy at the center of the Perseus cluster. Its multi-wavelength spectrum is similar to that of blazers, and thus a jet-origin of gamma-ray emissions is believed. In the optical and X-ray region, NGC…
We present a detailed analysis of the intrinsic X-ray absorption in the Seyfert 1 galaxy NGC 4151 using Chandra/HETGS data obtained 2002 May, as part of a program which included simultaneous UV spectra using HST/STIS and FUSE. NGC 4151 was…
We present an analysis of the co-added and individual 0.7-40 keV spectra from seven Suzaku observations of the Sy 1.5 galaxy NGC 5548 taken over a period of eight weeks. We conclude that the source has a moderately ionized, three-zone warm…
We present simultaneous observations by EUVE, ASCA, and RXTE of the type~1 Seyfert galaxy NGC 5548. These data indicate that variations in the EUV emission (at $\sim 0.2 $keV) appear to lead similar modulations in higher energy ($\ga 1…
Initial results on the iron K-shell line and reflection component in several AGN observed as part of the Suzaku Guaranteed time program are reviewed. This paper discusses a small sample of Compton-thin Seyferts observed to date with Suzaku;…
We present the results of X-ray spectral analysis of the Seyfert type 2 galaxy Mrk 417 observed by the NuSTAR (3-60 keV) and the Swift/BAT (14-150) observatories. The NuSTAR data shows a good fit with a baseline model which composed of an…
We report on the results of a three-year program of coordinated X-ray and optical monitoring of the narrow-line Seyfert 1 galaxy NGC 4051. The rapid continuum variations observed in the X-ray spectra are not detected in the optical,…
We report an analysis and modelling of new Suzaku observations of the Seyfert 1 galaxies Mrk509 and Mrk841, taken between April and November 2006,for Mrk509,and between January and July 2007,for Mrk841,for a total exposure time of ~100 ks…
NGC 4151 is the brightest Seyfert-1 active galaxy in the pass band of the Resolve calorimeter spectrometer aboard XRISM. It has been observed on 14 occasions, resulting in a total exposure of 893 ks. Herein, we report on an analysis of the…