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Related papers: Absorption Measure Distribution in AGN

200 papers

We performed near-diffraction-limited (~0.4 FWHM) N-band imaging of one of the nearest Active Galactic Nucleus (AGN) in M51 with 8.2m Subaru telescope to study the nuclear structure and spectral energy distribution (SED) at 8-13 um. We…

Astrophysics of Galaxies · Physics 2017-02-01 Youichi Ohyama , Satoki Matsushita , Nagisa Oi , Ai-Lei Sun

Ionized outflows in Active Galactic Nuclei (AGN) are thought to influence their nuclear and local galactic environment. However, the distance of the outflows with respect to the central engine is poorly constrained, which limits our…

High Energy Astrophysical Phenomena · Physics 2017-11-22 Junjie Mao , J. S. Kaastra , M. Mehdipour , A. J. J. Raassen , Liyi Gu , J. M. Miller

Spectral Energy Distribution (SED) of the broad-band continuum emission from black-hole accretion discs can serve as a tool to measure parameters of the central body and constrain the geometry of the inner accretion flow. We focus on the…

High Energy Astrophysical Phenomena · Physics 2023-06-21 Marcel Štolc , Michal Zajaček , Bożena Czerny , Vladimír Karas

We describe improved modelling of the emission by dust in a toroidal--like structure heated by a central illuminating source within Active Galactic Nuclei (AGN). We chose a simple but realistic torus geometry, a flared disc, and a dust…

Astrophysics · Physics 2009-11-13 J. Fritz , A. Franceschini , E. Hatziminaoglou

We use the very deep XMM-Newton observations in the CDF-S to measure the distribution of absorption in the AGN population. We describe the Monte Carlo method used to unveil the intrinsic properties of the AGN using their multi-band X-ray…

Astrophysics · Physics 2007-05-23 Tom Dwelly , Mathew J. Page

We model the observed X-ray spectral continuum shape, ionic column densities, and absorption measure distribution (AMD) of the warm absorber in the Seyfert galaxy NGC 3783. We assume a photo-ionized medium with a uniform total…

High Energy Astrophysical Phenomena · Physics 2016-03-07 R. W. Goosmann , T. Holczer , M. Mouchet , A. -M. Dumont , E. Behar , O. Godet , A. C. Goncalves , S. Kaspi

Hard X-ray surveys are an important tool for the study of active galactic nuclei (AGN): they provide almost an unbiased view of absorption in the extragalactic population, allow the study of spectral features such as reflection and high…

High Energy Astrophysical Phenomena · Physics 2013-02-12 Loredana Bassani , M. Molina , A. Malizia , F. Panessa , R. Landi , A. Bazzano , P. Ubertini , A. J. Bird , J. B. Stephen

Warm absorber (WA) is an ionised gas present in the line of sight to the AGN central engine. The effect of the absorber is imprinted in the absorption lines observed in X-ray spectra of AGN. In this work, we model the WA in Seyfert 1 galaxy…

Astrophysics of Galaxies · Physics 2016-01-26 T. P. Adhikari , A. Rozanska , M. Sobolewska , B. Czerny

Approximately 3-17 percent of Active Galactic Nuclei (AGN) without detected rest-frame UV/optical broad emission lines (type-2 AGN) do not show absorption in X-rays. The physical origin behind the apparently discordant optical/X-ray…

We present ongoing work on the spectral energy distributions (SEDs) of active galactic nuclei (AGNs), derived from X-ray, ultraviolet, optical, infrared and radio photometry and spectroscopy. Our work is motivated by new wide-field imaging…

Astrophysics of Galaxies · Physics 2020-06-17 M. J. I. Brown , K. J. Duncan , H. Landt , M. Kirk , C. Ricci , N. Kamraj

Active galactic nuclei (AGN) can launch outflows of ionized gas that may influence galaxy evolution, and quantifying their full impact requires spatially resolved measurements of the gas masses, velocities, and radial extents. We previously…

We present optical and X-ray data for a sample of serendipitous XMM-Newton sources that are selected to have 0.5-2 keV vs 2-4.5 keV X-ray hardness ratios which are harder than the X-ray background. The sources have 2-4.5 keV X-ray flux >=…

We combine bright XMM data with the Chandra Deep Field South observations in order to explore the behavior of the intrinsic AGN absorption, as a function of redshift and luminosity.Our sample consists of 359 sources selected in the hard 2-8…

Astrophysics · Physics 2009-11-11 A. Akylas , I. Georgantopoulos , A. Georgakakis , S. Kitsionas , E. Hatziminaoglou

Although soft X-ray absorption features in AGN were discovered almost ten years ago, the nature and location of the gas creating them has remained controversial. Guided by the results of recent high-resolution X-ray spectroscopy, we argue…

Astrophysics · Physics 2007-05-23 Julian H. Krolik , Gerard A. Kriss

We present the distributions of geometrical covering factors of active galactic nuclei (AGNs) dusty tori (f2) using an X-ray selected complete sample of 227 AGN drawn from the Bright Ultra-hard XMM-Newton Survey. The AGN have z from 0.05 to…

The geometry of the dust distribution within the inner regions of Active Galactic Nuclei (AGN) is still a debated issue and relates directly with the AGN unified scheme. Traditionally, models discussed in the literature assume one of two…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 A. Feltre , E. Hatziminaoglou , J. Fritz , A. Franceschini

The spectra of Active Galactic Nuclei (AGNs) are often characterized by a wealth of emission lines with different profiles and intensity ratios that led to a complicated classification. Their electro-magnetic radiation spans more than 10…

Present AGN models aiming to account for the observed infrared SEDs consider a physical description of the dust and a solution of the radiative transfer problem. Mid infrared spectra obtained at different spatial scales are presented. They…

Astrophysics · Physics 2009-11-10 Ralf Siebenmorgen , Andreas Efstathiou

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 particular we consider the complex of almost 60…

Astrophysics · Physics 2009-10-31 Fabrizio Nicastro , Fabrizio Fiore , Giorgio Matt

According to unified schemes of Active Galactic Nuclei (AGN), the central engine is surrounded by dusty, optically thick clouds in a toroidal structure. We have recently developed a formalism that for the first time takes proper account of…

Astrophysics · Physics 2009-11-13 Maia Nenkova , Matthew M. Sirocky , Zeljko Ivezic , Moshe Elitzur