相关论文: Obscuring clouds playing hide-and-seek in the Acti…

First indications of the warm/hot intergalactic medium, tracing out the large scale structure of the universe, have been obtained in sensitive Chandra and XMM-Newton high resolution absorption line spectroscopy of bright blazars. High…

We report on the analysis of a long XMM-Newton EPIC observation in 2001 May of the Narrow Line Seyfert 1 galaxy Mkn 766. The 3-11 keV spectrum exhibits a moderately steep power law continuum, with a broad emission line at ~6.7 keV, probably…

MCG-6-30-15 is the archetypal example of a type I active galaxy showing broad "red-wing" emission in its X-ray spectrum at energies below the 6.4 keV Fe K-alpha emission line and a continuum excess above 20 keV. Miller et al. (2008) showed…

We present results from a half-day observation by XMM-Newton of the nucleus of the nearby Seyfert 2 galaxy NGC 6300. The X-ray spectrum of the nucleus consists of a heavily absorbed hard component dominating the 3--10 keV band and a soft…

The Narrow Line Seyfert 1 galaxy NGC 4051 was observed in one of its prolonged low-lux states by XMM-Newton in November 2002. Here we present the results of an analysis of EPIC-pn data obtained during the observation. Within the low state,…

We present the first high-resolution, soft-X-ray spectrum of the prototypical Seyfert 2 galaxy, NGC 1068. This spectrum was obtained with the XMM-Newton Reflection Grating Spectrometer. Emission lines from H-like and He-like low-Z ions…

A model for the inner regions of accretion flows is presented where, due to disc instabilities, cold and dense material is clumped into deep sheets or rings. Surrounding these density enhancements is hot, tenuous gas where coronal…

We present the results of an ASCA observation of the low-luminosity Seyfert 1.5 galaxy NGC 5033. A point-like X-ray source with a luminosity of 2.3x10^{41} erg s^{-1} in the 2--10 keV band (at 18.7 Mpc; Tully 1988, AAA045.002.054) was…

We present a study of reddening and absorption towards the Narrow Line Regions (NLR) in active galactic nuclei (AGN) selected from the Revised Shapley-Ames, 12mu, and Swift/Burst Alert Telescope samples. For the sources in host galaxies…

The soft X-ray band of many active galactic nuclei (AGNs) is affected by obscuration due to partially ionised matter crossing our line of sight. In this context, two past XMM-Newton observations (6 months apart) and a simultaneous…

We observed with XMM-Newton 4 objects selected from the Grossan catalog, with the aim to search for new 'changing-look' AGN. The sample includes all the sources which showed in subsequent observations a flux much lower than the one measured…

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…

A sample of X-ray and optically selected narrow emission-line galaxies (769 sources) from the 3XMM catalogue cross-correlated with SDSS (DR9) catalogue has been studied. Narrow-emission line active galactic nuclei (AGN; type-2) have been…

We present an X-ray spectral analysis of 21 low redshift quasars observed with XMM-Newton EPIC. All the sources are Palomar Green quasars with redshifts between 0.05 and 0.4 and have low Galactic absorption along the line-of-sight. A large…

We present and discuss a "3-dimensional" diagnostic diagram for Seyfert2 galaxies obtained by means of X-ray and [OIII] data on a large sample of objects (reported in the Appendix). The diagram shows the Kalpha iron line equivalent width as…

During an XMM-Newton observation of the galactic supernova remnant G21.5-09 a bright, previously uncatalogued, source (XMMU J183225.4-103645) was detected 18 arcmin from G21.5-09. The European Photon Imaging Camera data inside 1 arcmin…

We present the spectral analysis of an early XMM-Newton observation of the luminous Seyfert 1 galaxy Markarian 509. We find the hard (2-10 keV) continuum slope, including reflection, to be somewhat flatter ($\Gamma=1.75$) than for a typical…

Scanning and pointed RXTE observations of the nearby Seyfert 2 galaxy NGC 6300 reveal that it is a source of hard X-ray continuum and large equivalent width Fe K$\alpha$ emission. These properties are characteristic of Compton-reflection…

XMM-Newton observed the Seyfert 1.9 galaxy NGC 4258 in December 2000. At energies above 2 keV a hard nuclear point source is resolved that can be fitted by a highly absorbed power-law spectrum (NH = (8.0+-0.4)x10^22 cm^-2, photon index…

We present two NuSTAR observations of the local Seyfert 2 active galactic nucleus (AGN) and an ultraluminous X-ray source (ULX) candidate in NGC 5643. Together with archival data from Chandra, XMM-Newton and Swift-BAT, we perform a…