Related papers: AGN Outflows: Analysis of the Absorption Troughs
To explain the properties of the local galaxy population, theoretical models require active galactic nuclei (AGN) to inject energy into host galaxies, thereby expelling outflows of gas that would otherwise form stars. Observational tests of…
We have measured the X-ray spectral properties of a complete flux-limited sample of bright AGNs from HEAO-1 all-sky catalogs to investigate their statistics and provide greater constraints on the bright-end of the hard X-ray luminosity…
The X-ray emission of radio-loud (RL) AGNs is a powerful tool for probing the structure of the accretion flow in these objects. We review recent spectral and variability studies of RL AGNs, which show that these systems have systematically…
We examine the properties of the X-ray detected, Infrared Excess AGN or Dust Obscured Galaxies (DOGs) in the Chandra Deep Fields (CDF). We find 26 X-ray selected sources which obey the 24 micron to R-band flux ratio criterion f_24/f_R>1000.…
We present an optical spectroscopic study of a 90% complete sample of 17 nearby ULIRGs with optical Seyfert nuclei, with the aim of investigating the nature of the nuclear warm gas outflows. A high proportion (94%) of our sample show…
Using the Far Ultraviolet Spectroscopic Explorer (FUSE) we have obtained 87 spectra of 57 low-redshift (z<0.15) active galactic nuclei (AGN). This sample comprises 53 Type 1 AGN and 4 Type 2. All the Type 1 objects show broad O VI 1034…
The spectrum of the hard X-ray background records the history of accretion processes integrated over the cosmic time. Several pieces of observational and theoretical evidence indicate that a significant fraction of the energy density is…
The estimate of the number and space density of obscured AGN over cosmic time still represents an open issue. While the obscured AGN population is a key ingredient of the X-ray background synthesis models and is needed to reproduce its…
Active galactic nucleus (AGN) driven outflows can have a significant impact on the evolution of the host galaxy. In this work, we compare the properties of galaxies that hosts AGNs with and without outflows. Our sample consists of 103 AGNs…
We use Chandra data to study the incidence and properties of Active Galactic Nuclei (AGN) in 16 intermediate redshift ($0.5 < z < 1.1$) X-ray-selected galaxy groups in the Chandra Deep Field-South. We measure an AGN fraction of $f(L_{X,H} >…
Galaxy-scale outflows are nowadays observed in many active galactic nuclei (AGNs); however, their characterisation in terms of (multi-) phase nature, amount of flowing material, effects on the host galaxy, is still unsettled. In particular,…
It is well accepted that unabsorbed as well as absorbed AGN are needed to explain the nature and the shape of the Cosmic X-ray background, even if the fraction of highly absorbed objects (dubbed Compton-thick sources) substantially still…
We examine the 24 micron to X-ray color of 157 X-ray--selected AGN as a function of X-ray obscuration and optical classification in the Chandra Deep Field South. The sample consists of the Chandra hard--band detections with hard flux…
We analyze the Chandra X-ray spectrum obtained with the HETGS grating spectrometer of IRAS 13349+2438, which has one of the richest absorption spectra of a quasar outflow. Absorption from almost all charge states of Fe is detected. This…
We present the results of the XMM-Newton and NuSTAR observations taken as part of the ongoing, intensive multi-wavelength monitoring program of the Seyfert 1 galaxy Mrk 817 by the AGN Space Telescope and Optical Reverberation Mapping 2 (AGN…
We report two epochs of Chandra-ACIS X-ray imaging spectroscopy of the nearby bright Type IIn supernova SN 2010jl, taken around 2 months and then a year after the explosion. The majority of the X-ray emission in both the spectra is…
We study the properties of a sample of 211 heavily-obscured Active Galactic Nucleus (AGN) candidates in the Extended Chandra Deep Field-South selecting objects with f_24/f_R>1000 and R-K>4.5. Of these, 18 were detected in X-rays and found…
We consider energy budgets and radiative history of 8 fading AGN, identified from mismatch between the ionizion of very extended (>10 kpc) ionized clouds and the luminosity of the nucleus viewed directly. All show significant fading on…
We report on our observations of the 79 and 119um doublet transitions of OH for 24 local (z<0.262) ULIRGs observed with Herschel-PACS as part of the Herschel ULIRG Survey (HERUS). Some OH119 profiles display a clear P-Cygni shape and…
We present a Chandra-LETGS observation of the Seyfert 1 galaxy Mrk 279. This observation was carried out simultaneously with HST-STIS and FUSE, in the context of a multiwavelength study of this source. The Chandra pointings were spread over…