The soft X-ray polarization in obscured AGN (2009)
Bianchi, Stefano, Matt, Giorgio, Tamborra, Francesco, Chiaberge, Marco, Guainazzi, Matteo, Marinucci, Andrea
The soft X-ray emission in obscured active galactic nuclei (AGN) is dominated by emission lines, produced in a gas photoionized by the nuclear continuum and likely spatially coincident with the...
CAIXA: a Catalogue of AGN In the XMM-Newton Archive II. Multiwavelength correlations (2009)
Bianchi, Stefano, Bonilla, Nuria Fonseca, Guainazzi, Matteo, Matt, Giorgio, Ponti, Gabriele
We presented CAIXA, a Catalogue of AGN in the XMM-Newton Archive, in a companion paper. Here, a systematic search for correlations between the X-ray spectral properties and the multiwavelength data...
CAIXA: a Catalogue of AGN In the XMM-Newton Archive - Correlations (2009)
Bianchi, Stefano, Bonilla, Nuria Fonseca, Guainazzi, Matteo, Matt, Giorgio, Ponti, Gabriele
We presented CAIXA, a Catalogue of AGN in the XMM-Newton Archive, in Bianchi et al. (2009). It consists of all the radio-quiet X-ray unobscured (N$_\mathrm{H}99.9 % confidence level) correlations.
Bianchi, Stefano, Piconcelli, Enrico, Chiaberge, Marco, Bailon, Elena Jimenez, Matt, Giorgio, Fiore, Fabrizio
We present the results of a Suzaku monitoring campaign of the Seyfert 2 galaxy, NGC7582. The source is characterized by very rapid (on timescales even lower than a day) changes of the column density...
XEUS: the physics of the hot evolving universe (2009)
Arnaud, Monique, Barcons, Xavier, Barret, Didier, Bautz, Marshall, Bellazzini, Ronaldo, Bleeker, Johan, ...
CAIXA: a Catalogue of AGN In the XMM-Newton Archive I. Spectral analysis (2008)
Bianchi, Stefano, Guainazzi, Matteo, Matt, Giorgio, Bonilla, Nuria Fonseca, Ponti, Gabriele
We present CAIXA, a Catalogue of AGN In the XMM-Newton Archive. It consists of all the radio-quiet X-ray unobscured ($\mathrm{N_H}
XPOL: a photoelectric polarimeter onboard XEUS (2008)
Costa, Enrico, Bellazzini, Ronaldo, Bregeon, Jean, Brez, Alessandro, Frutti, Massimo, Di Cosimo, Sergio, ...
The XEUS mission incorporates two satellites: the Mirror Spacecraft with 5 m2 of collecting area at 1 keV and 2 m2 at 7 keV, and an imaging resolution of 5" HEW and the Payload Spacecraft which...
X-ray polarimetry on-board HXMT (2008)
Soffitta, Paolo, Bellazzini, Ronaldo, Tagliaferri, Gianpiero, Costa, Enrico, Pareschi, Giovanni, Basso, Stefano, ...
The development of micropixel gas detectors, capable to image tracks produced in a gas by photoelectrons, makes possible to perform polarimetry of X-ray celestial sources in the focus of grazing...
A BLR origin for the iron K$\alpha$ line in NGC7213 (2008)
Bianchi, Stefano, La Franca, Fabio, Matt, Giorgio, Guainazzi, Matteo, Bailon, Elena Jimenez, Longinotti, Anna Lia, ...
The X-ray spectrum of NGC7213 is known to present no evidence for Compton reflection, a unique result among bright Seyfert 1s. The observed neutral iron K$\alpha$ line, therefore, cannot be...
Chandra unveils a binary Active Galactic Nucleus in Mrk463 (2008)
Bianchi, Stefano, Chiaberge, Marco, Piconcelli, Enrico, Guainazzi, Matteo, Matt, Giorgio
We analyse Chandra, XMM-Newton and HST data of the double-nucleus Ultraluminous Infrared Galaxy (ULIRG), Mrk463. The Chandra detection of two luminous ($\mathrm{L}_\mathrm{2-10 keV}=1.5\times10^{43}$...
An X-ray Polarimeter for HXMT Mission (2007)
Costa, Enrico, Bellazzini, Ronaldo, Tagliaferri, Gianpiero, Baldini, Luca, Basso, Stefano, Bregeon, Johan, ...
The development of micropixel gas detectors, capable to image tracks produced in a gas by photoelectrons, makes possible to perform polarimetry of X-ray celestial sources in the focus of grazing...
On the Iwasawa-Taniguchi effect of radio-quiet AGN (2007)
Bianchi, Stefano, Guainazzi, Matteo, Matt, Giorgio, Bonilla, Nuria Fonseca
The existence of an anti-correlation between the Equivalent Width (EW) of the neutral narrow core of the iron Kalpha emission line and the 2-10 keV luminosity (the so-called `X-ray Baldwin' or...
Compton thick AGN in the Suzaku era (2007)
Comastri, Andrea, Gilli, Roberto, Vignali, Cristian, Matt, Giorgio, Fiore, Fabrizio, Iwasawa, Kazushi
The properties of unobscured AGN observed by XMM-Newton (2006)
Bianchi, Stefano, Guainazzi, Matteo, Matt, Giorgio, Bonilla, Nuria Fonseca
Multiwavelength analysis on large samples of AGN provides an excellent tool to understand the physics of these objects. We present the largest catalog of XMM-Newton targeted AGN, all with high SNR...
General Relativity effects and line emission (2006)
General Relativity effects (gravitational redshift, light bending, ...) strongly modify the characteristics of the lines emitted close to the Black Hole in Active Galactic Nuclei and Galactic Black...
A photoelectric polarimeter for XEUS: a new window in x-ray sky (2006)
Bellazzini, Ronaldo, Baldini, Luca, Bitti, Francesco, Brez, Alessandro, Cavalca, Francesco, Latronico, Luca, ...
XEUS is a large area telescope aiming to rise X-ray Astronomy to the level of Optical Astronomy in terms of collecting areas. It will be based on two satellites, locked on a formation flight, one...
An X-ray polarimeter for hard X-ray optics (2006)
Muleri, Fabio, Bellazzini, Ronaldo, Costa, Enrico, Soffitta, Paolo, Lazzarotto, Francesco, Feroci, Marco, ...
Development of multi-layer optics makes feasible the use of X-ray telescope at energy up to 60-80 keV: in this paper we discuss the extension of photoelectric polarimeter based on Micro Pattern Gas...
POLARIX: a small mission of x-ray polarimetry (2006)
Costa, Enrico, Bellazzini, Ronaldo, Soffitta, Paolo, Muleri, Fabio, Feroci, Marco, Frutti, Massimo, ...
X-Ray Polarimetry can be now performed by using a Micro Pattern Gas Chamber in the focus of a telescope. It requires large area optics for most important scientific targets. But since the technique...
A possible bias on the estimate of Lbol/Ledd in AGN as a function of luminosity and redshift (2006)
Lamastra, Alessandra, Matt, Giorgio, Perola, G. Cesare
The BH mass (and the related Eddington ratio) in broad line AGN is usually evaluated by combining estimates (often indirect) of the BLR radius and of the FWHM of the broad lines, under the assumption...
The XMM-Newton view of GRS1915+105 during a "plateau" (2006)
Martocchia, Andrea, Matt, Giorgio, Belloni, Tomaso, Feroci, Marco, Karas, Vladimir, Ponti, Gabriele
Two XMM-Newton observations of the black-hole binary GRS1915+105 were triggered in 2004 (April 17 and 21), during a long "plateau" state of the source. We analyzed the data collected with EPIC-pn in...
The XMM-Newton view of GRS1915+105 during a "plateau" (2006)
Martocchia, Andrea, Matt, Giorgio, Belloni, Tomaso, Feroci, Marco, Karas, Vladimir, Ponti, Gabriele
Two XMM-Newton observations of the black-hole binary GRS1915+105 were triggered in 2004 (April 17 and 21), during a long "plateau" state of the source. We analyzed the data collected with EPIC-pn in...
The XMM-Newton View of GRS1915+105 (2006)
Martocchia, Andrea, Matt, Giorgio, Belloni, Tomaso, Feroci, Marco, Karas, Vladimir, Ponti, Gabriele
(abridged) Two XMM-Newton observations of the black-hole binary GRS1915+105 were triggered in 2004, during a long "plateau" state of the source. (...) While the light curves show just small amplitude...
The XMM-Newton view of GRS1915+105 during a "plateau" (2006)
Martocchia, Andrea, Matt, Giorgio, Belloni, Tomaso, Feroci, Marco, Karas, Vladimir, Ponti, Gabriele
Two XMM-Newton observations of the black-hole binary GRS1915+105 were triggered in 2004 (April 17 and 21), during a long "plateau" state of the source. We analyzed the data collected with EPIC-pn in...
The XMM-Newton View of GRS1915+105 (2006)
Martocchia, Andrea, Matt, Giorgio, Belloni, Tomaso, Feroci, Marco, Karas, Vladimir, Ponti, Gabriele
(abridged) Two XMM-Newton observations of the black-hole binary GRS1915+105 were triggered in 2004, during a long "plateau" state of the source. (...) While the light curves show just small amplitude...
The XMM-Newton view of GRS1915+105 during a "plateau" (2006)
Martocchia, Andrea, Matt, Giorgio, Belloni, Tomaso, Feroci, Marco, Karas, Vladimir, Ponti, Gabriele
Two XMM-Newton observations of the black-hole binary GRS1915+105 were triggered in 2004 (April 17 and 21), during a long "plateau" state of the source. We analyzed the data collected with EPIC-pn in...
The XMM-Newton View of GRS1915+105 (2006)
Martocchia, Andrea, Matt, Giorgio, Belloni, Tomaso, Feroci, Marco, Karas, Vladimir, Ponti, Gabriele
(abridged) Two XMM-Newton observations of the black-hole binary GRS1915+105 were triggered in 2004, during a long "plateau" state of the source. (...) While the light curves show just small amplitude...
The XMM-Newton view of GRS1915+105 during a "plateau" (2006)
Martocchia, Andrea, Matt, Giorgio, Belloni, Tomaso, Feroci, Marco, Karas, Vladimir, Ponti, Gabriele
Two XMM-Newton observations of the black-hole binary GRS1915+105 were triggered in 2004 (April 17 and 21), during a long "plateau" state of the source. We analyzed the data collected with EPIC-pn in...
The XMM-Newton View of GRS1915+105 (2006)
Martocchia, Andrea, Matt, Giorgio, Belloni, Tomaso, Feroci, Marco, Karas, Vladimir, Ponti, Gabriele
(abridged) Two XMM-Newton observations of the black-hole binary GRS1915+105 were triggered in 2004, during a long "plateau" state of the source. (...) While the light curves show just small amplitude...
A model for the X-ray absorption in Compton--thin AGN (2005)
Lamastra, Alessandra, Perola, G. Cesare, Matt, Giorgio
The fraction of AGN with photoelectric absorption in the X-rays ranging from NH of 10^{22} up to about 10^{24} cm^{-2} (Compton-thin) appears observationally to be anticorrelated to their luminosity...
The XMM-Newton View of GRS1915+105 (2005)
Martocchia, Andrea, Matt, Giorgio, Belloni, Tomaso, Feroci, Marco, Karas, Vladimir, Ponti, Gabriele
(abridged) Two XMM-Newton observations of the black-hole binary GRS1915+105 were triggered in 2004, during a long "plateau" state of the source. (...) While the light curves show just small amplitude...
A Compton reflection dominated spectrum in a peculiar accreting neutron star (2005)
Rea, Nanda, Stella, Luigi, Israel, Gian Luca, Matt, Giorgio, Zane, Silvia, Segreto, Alberto, ...
We report on a puzzling event occurred during a long BeppoSAX observation of the slow-rotating binary pulsar GX 1+4. During this event, lasting about 1 day, the source X-ray flux was over a factor 10...
Fe XXV and Fe XXVI lines from low velocity, photoionised gas in the X-ray spectra of AGN (2004)
Bianchi, Stefano, Matt, Giorgio, Nicastro, Fabrizio, Porquet, Delphine, Dubau, Jacques
We have calculated the equivalent widths of the absorption lines produced by Fe XXV and Fe XXVI in a Compton-thin, low-velocity photoionised material illuminated by the nuclear continuum in AGN. The...
A puzzling event during the X-ray emission of the binary system GX 1+4 (2004)
Rea, Nanda, Stella, Luigi, Israel, Gian Luca, Matt, Giorgio, Zane, Silvia, Segreto, Alberto, ...
We report on a long X-ray observation of the slow-rotating binary pulsar GX 1+4. BeppoSAX observed, in the 0.1-200 keV energy range, an event in which the source flux dropped for almost a day, and...
The complex X-ray spectrum of NGC 4507 (2004)
Matt, Giorgio, Bianchi, Stefano, D'Ammando, Filippo, Martocchia, Andrea
XMM-Newton and Chandra/HETG spectra of the Compton-thin (NH 4x10^{23} cm^{-2}) Seyfert 2 galaxy, NGC 4507, are analyzed and discussed. The main results are: a) the soft X-ray emission is rich in...
X-ray polarization properties of the accretion column in magnetic CVs (2004)
The accretion column in magnetic Cataclysmic Variables may have a not negligible Thomson optical depth. A fraction of the thermal radiation from the post-shock region may therefore be scattered - and...
X-ray broad band spectral properties of intermediate polars (2004)
Matt, Giorgio., De Martino, Domitilla, Belloni, Tomaso, Chiappetti, Lucio, Haberl, Frank
The high energy emission line spectrum of NGC 1068 (2003)
Matt, Giorgio, Bianchi, Stefano, Guainazzi, Matteo, Molendi, Silvano
We present and discuss the high energy (E>4 keV) XMM-Newton spectrum of the Seyfert 2 galaxy, NGC 1068. Possible evidence for flux variability in both the neutral and ionized reflectors with respect...
Iron and Nickel properties in the X-ray reflecting region of the Circinus Galaxy (2003)
Molendi, Silvano, Bianchi, Stefano, Matt, Giorgio
We discuss the iron and nickel properties in the nuclear X-ray reflecting region of the Circinus Galaxy, studied with XMM-Newton. The main results are: a) from the depth of the Fe Kalpha edge, a...
The properties of the absorbing and line emitting material in IGR J16318-4848 (2003)
Matt, Giorgio, Guainazzi, Matteo
We have performed a detailed analysis of the XMM-Newton observation of IGR J16318-4848, to study the properties of the matter responsible for the obscuration and for the emission of Fe and Ni lines....
On the Nature of Hidden Broad Line Regions in Seyfert 2 Galaxies (2002)
Martocchia, Andrea, Matt, Giorgio
We consider the sample of Tran (2001) to study the X-ray properties of Seyfert 2 galaxies with and without polarized broad lines.
Ionized iron K\alpha lines in AGN X-ray spectra (2002)
Bianchi, Stefano, Matt, Giorgio
The Equivalent Widths (EW) of the He- and H-like iron lines produced in photoionized, circumnuclear matter of AGN are calculated with respect to both the reflected and the total continua. We found...
On the origin of the broad, relativistic iron line of MCG-6-30-15 observed by XMM-Newton (2002)
Martocchia, Andrea, Matt, Giorgio, Karas, Vladimir
The relativistic iron line profile recently observed by XMM-Newton in the spectrum of the Seyfert 1 galaxy MCG--6-30-15 (Wilms et al., 2001) is discussed in the framework of the lamp-post model. It...
The X-ray view of highly obscured AGN (2001)
The properties of Compton-thick AGN are reviewed, with particular emphasis on BeppoSAX hard X-ray observations. I also discuss evidence for the presence of Compton-thick, circumnuclear matter in...
Weak Reprocessed Features in the Broad Line Radio Galaxy 3C382 (2001)
Grandi, Paola, Maraschi, Laura, Urry, C. Meg, Matt, Giorgio
We present a detailed X-ray study of the Broad Line Radio Galaxy 3C382, observed with the BeppoSAX satellite in a very bright state. The continuum emission is well modeled with a power law that...
The circumnuclear X-ray reflectors in NGC 1068 and the Circinus Galaxy (2000)
Bianchi, Stefano, Matt, Giorgio, Iwasawa, Kazushi
The ASCA and BeppoSAX spectra of the Circinus Galaxy and NGC 1068 are analysed and compared with photoionization models based on cloudy. In the case of Circinus, a single, mildly ionized reflector...
X-ray spectral signatures of accreting black holes (2000)
Karas, Vladimir, Matt, Giorgio, Miller, John C., Martocchia, Andrea
The BeppoSAX observation of Mrk 766 (2000)
Matt, Giorgio, Perola, G. C., Fiore, F., Guainazzi, M., Nicastro, F., Piro, L.
The Narrow Line Seyfert 1 galaxy Mrk 766 has been observed by BeppoSAX on May 1997. The source was fairly variable, both in flux and spectrum, during the observation. The variability is the largest...
Sub-mm and X-ray background: Two unrelated phenomena? (2000)
Severgnini, Paola, Maiolino, Roberto, Salvati, Marco, Axon, David, Cimatti, Andrea, Fiore, Fabrizio, ...
Also archived in: arXiv:astro-ph/0006233 v1 16 Jun 2000
Sub-mm and X-ray background: Two unrelated phenomena? (2000)
Severgnini, Paola, Maiolino, Roberto, Salvati, Marco, Axon, David, Cimatti, Andrea, Fiore, Fabrizio, ...
Also archived in: arXiv:astro-ph/0006233 v1 16 Jun 2000
The broad band spectrum and variability of Seyfert 1 (2000)
Recent results on the X-ray spectrum and variability of Seyfert 1 galaxies are reviewed. New spectral results from BeppoSAX observations are also presented and briefly discussed.
Resolving the 10-40 keV Cosmic X-ray Background with Constellation-X (2000)
Matt, Giorgio, Pompilio, Fulvio, La Franca, Fabio
The energy density of the Cosmic X-ray background (XRB) peaks around 30 keV (see Figure 1), an energy not yet probed by focussing imaging instruments. The first hard X-ray telescope due to fly on a...
Dust lanes, thick absorbers, and the unification model for Seyfert galaxies (2000)
A modification of the popular unification model for Seyfert galaxies is proposed, which takes into account recent observational findings on the statistical properties of both type 1 and type 2...
The hard X-ray spectrum of Compton-thick Seyfert 2 galaxies and the synthesis of the XRB (1999)
Matt, Giorgio, Pompilio, Fulvio, La Franca, Fabio
A synthesis model for the cosmic X-ray Background (XRB) is presented, which includes a proper treatment of Compton scattering in the absorbing matter for type 2 AGN. Evidence for a decrease of the...
The X-ray background and the evolution of AGN (1999)
Pompilio, Fulvio, La Franca, Fabio, Matt, Giorgio
We discuss the constraints on the AGN evolution from the cosmic X-ray background and source counts. A synthesis model to fit the X-ray background is presented. In the model, the spectrum of type 2...
X-ray spectra transmitted through Compton-thick absorbers (1999)
Matt, Giorgio, Pompilio, Fulvio, La Franca, Fabio
X-ray spectra transmitted through matter which is optically thick to Compton scattering are computed by means of Monte Carlo simulations. Applications to the BeppoSAX data of the Seyfert 2 galaxy in...
Nicastro, Fabrizio, Fiore, Fabrizio, Matt, Giorgio
We present photoionization models accounting for both photoelectric and resonant absorption. Resonance absorption lines from C, O, Ne, Mg, Si S and Fe between 0.1 and 10 keV are treated. In...
X/gamma-ray spectra of Seyferts and BeppoSAX observations (1998)
BeppoSAX results on Seyfert galaxies are reviewed and discussed.
Studying circumnuclear matter in AGN with X-ray spectroscopy (1998)
I discuss the advances in our understanding of the physics and morphology of the innermost regions of AGNs which will be possible thanks to the XMM unprecedented sensitivity and its moderate to high...
Seyfert Galaxies and BeppoSAX (1997)
The contributions that BeppoSAX is expected to give and, after one and a half year of operation, has already given to our knowledge of both type 1 and type 2 Seyfert galaxies are outlined and...
The X-ray spectrum of Compton-thick Seyfert 2 Galaxies (1996)
Current ideas on the X-ray spectrum of Compton-thick Seyfert 2 galaxies are reviewed, and a brief description of the four presently known sources belonging to this class are given.
Ghisellini, Gabriele, Haardt, Francesco, Matt, Giorgio
The presence of an obscuring torus around the nucleus of Seyfert galaxies, as supposed in the popular unification scheme, can strongly modify the X--ray spectrum for both type 1 and 2 Seyfert...