Related papers: X-Ray Spectral Model from Clumpy Torus and Its App…
X-ray spectra of active galactic nuclei (AGN) are usually described as power law spectra, characterized by the spectral slope $\alpha$ or photon index $\Gamma$. Here we discuss the X-ray spectral properties within the framework of clumpy…
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 galaxies. We find that if the torus is Compton…
The synthesis model for the cosmic X-ray background (XRB) -based on the integrated emission of Active Galactic Nuclei (AGNs)- is complemented with new observational results. We adopt the most recent estimates of the AGN X-ray luminosity…
A thermal active galactic nucleus (AGN) consist of a powerful, broad-band continuum source that is surrounded by several reprocessing media with different geometries and compositions. Here we investigate the expected spectropolarimetric…
We use photometric and spectroscopic infrared observations obtained with the Spitzer Space Telescope of 12 radio-loud active galactic nuclei (AGN) to investigate the dust geometry. Our approach is to look at the change of the infrared…
We have calculated a series of models of outflows from the obscuring torus in active galactic nuclei (AGN). Our modeling assumes that the inner face of a rotationally supported torus is illuminated and heated by the intense X-rays from the…
We present the results of X-ray spectral analysis of 22 active galactic nuclei (AGNs) with a small scattering fraction selected from the Second XMM-Newton Serendipitous Source Catalogue using hardness ratios. They are candidates of buried…
Recent high angular resolution observations resolved for the first time the mid-infrared (MIR) structure of nearby active galactic nuclei (AGN). Surprisingly, they revealed that a major fraction of their MIR emission comes from the polar…
This work discusses the broadband X-ray spectral analysis of 11 candidate heavily-obscured active galactic nuclei (AGN) selected based on their infrared and X-ray properties by a recently published machine learning algorithm. This paper is…
Contemporary radiation-magnetohydrodynamic simulation of the AGNs predicts presence of the hot and strong accretion disk wind, which gets unstable far from the central region and turns into gas clumps. These inner-wind and outer clumps may…
Recent success in explaining several properties of the dusty torus around the central engine of active galactic nuclei has been gathered with the assumption of clumpiness. The properties of such clumpy dusty tori can be inferred by…
Variable X-ray absorption has been observed in active galactic nuclei (AGN) on several time scales. Observations allow us to identify the absorber with clouds associated either with the clumpy torus (parsec scales, long timescales) or with…
The hard X-ray emission of active galactic nuclei (AGN), and in particular, the reflection component, is shaped by the innermost and outer regions of the galactic nucleus. Our main goal is to investigate the variation of the Compton hump…
The broad band spectra of two Swift/BAT AGNs obtained from Suzaku follow-up observations are studied: NGC 612 and NGC 3081. Fitting with standard models, we find that both sources show similar spectra characterized by a heavy absorption…
With an aim to unveil the population of obscured AGN hosted in high-$z$ dust-obscured galaxies (DOGs), we performed X-ray spectral study of $34$ DOGs ($0.59$ $\leq$ $z$ $\leq$ $4.65$) lying within $5.3$ deg$^{2}$ of the XMM-SERVS coverage…
We present the results from an X-ray spectral analysis of active galactic nuclei (AGN) in the Chandra Deep Field-South, AEGIS-XD and Chandra-COSMOS surveys, focussing on the identification and characterisation of the most heavily obscured,…
The existence of an anti-correlation between the equivalent width (EW) of the narrow core of the iron Kalpha line and the luminosity of the continuum (i.e. the X-ray Baldwin effect) in type-I active galactic nuclei has been confirmed over…
We present a spectral analysis of NuSTAR and NICER observations of the luminous, persistently accreting neutron star (NS) low-mass X-ray binary Cygnus X-2. The data were divided into different branches that the source traces out on the…
In this study, we investigate the line emissions from cold molecular gas based on our previous "radiation-driven fountain model" (Wada 2016), which reliably explains the spectral energy distribution of the nearest type 2 Seyfert galaxy, the…
An interesting feature in active galactic nuclei (AGN) accreting at low rate is the weakness of the reflection features in their X-ray spectra, which can result from the gradual disappearance of the torus with decreasing accretion rates. It…