相关论文: X-ray observations of NGC 1365: time-resolved ecli…

We present multiple Chandra and XMM-Newton observations of the type 1.8 Seyfert Galaxy NGC 1365, which shows the most dramatic X-ray spectral changes observed so far in an AGN: the source switched from reflection dominated to transmission…

We present an occultation of the central X-ray emitting region in the Seyfert Galaxy NGC 1365. This extreme spectral variation (from Compton-thin to reflection-dominated and back to Compton-thin in four days) has been caught in a ten days…

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…

Active Galactic Nuclei (AGN) show excess X-ray emission above 10 keV compared with extrapolation of spectra from lower energies. Risaliti et al. have recently attempted to model the hard X-ray excess in the type 1.8 AGN NGC 1365, concluding…

We present the first XRISM/Resolve observations of the active galactic nucleus, NGC 1365, obtained in 2024 February and July. NGC 1365 is known for rapid transitions between Compton-thick and Compton-thin states, along with strong…

We present the analysis of a Chandra High-Energy Transmission Grating (HETG) observation of the local Seyfert galaxy NGC 1365. The source, well known for its dramatic X-ray spectral variability, was caught in a reflection-dominated,…

We present a new Suzaku observation of the obscured AGN in NGC 1365, revealing an unexpected excess of X-rays above 20 keV of at least a factor ~2 with respect to the extrapolation of the best-fitting 3-10 keV model. Additional Swift-BAT…

We report the discovery of a Compton-thick Active Galactic Nucleus (AGN) at z=4.76 in the 4 Ms Chandra Deep Field South. This object was selected as a V-band dropout in HST/ACS images and previously recognized as an AGN from optical…

We present new evidence of X-ray absorption variability on time scales from a few hours to a few days for several nearby bright AGNs. The observed N_H variations imply that the X-ray absorber is made of clouds eclipsing the X-ray source…

We present a Chandra monitoring campaign of the highly variable Seyfert galaxy UGC 4203 (the "Phoenix Galaxy") which revealed variations in the X-ray absorbing column density on time scales of two weeks. This is the third, clear case, after…

We present the time-resolved spectral analysis of the XMM-Newton data of NGC 1365, collected during one XMM-Newton observation, which caught this "changing-look" AGN in a high flux state characterized also by a low column density…

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 an X-ray spectral and spatial analysis of the composite starburst/Seyfert galaxy NGC 1365. Excellent fits of the ROSAT PSPC spectrum are obtained by combining a soft thermal component with a hard powerlaw. The hard component may…

We present 26 point-sources discovered with Chandra within 200" (~20kpc) of the center of the barred supergiant galaxy NGC 1365. The majority of these sources are high-mass X-ray binaries, containing a neutron star or a black hole accreting…

Aims. We present a 0.2--200 keV broad-band study of absorbed AGN observed with INTEGRAL, XMM-Newton, Chandra and ASCA to investigate the continuum shape and the absorbing/reflecting medium properties. Methods. The sources are selected in…

"Changing look" Active Galactic Nuclei (AGN) are a subset of Seyfert galaxies characterized by rapid transitions between Compton-thin and Compton-thick regimes. In their Compton-thin state, the central engine is less obscured, hence…

We observed 7 INTEGRAL sources with the Chandra X-ray Observatory to refine their localization to ~2 arcsec and to study their X-ray spectra. Two sources are inferred to have a Galactic origin: IGR J08390-4833 is most likely a magnetic…

We present a multi-wavelength study of the active nucleus and the off-nuclear X-ray sources in the nearby spiral galaxy, NGC 1365 using three simultaneous UV/X-ray observations by AstroSat over a two months period and archival IR…

We present a deep (~5.8 days) 0.3-2 keV high-resolution spectrum of NGC1365, collected with the reflection grating spectrometer (RGS) on board XMM-Newton. The spectrum is dominated by strong recombination lines of He- and H-like transitions…

In 2016 we carried out a Swift monitoring program to track the X-ray hardness variability of eight type-I AGN over a year. The purpose of this monitoring was to find intense obscuration events in AGN, and thereby study them by triggering…