Related papers: New results from the HRX BL Lac sample
This paper is a sequel to the extensive study of warm absorber (WA) in X-rays carried out using high resolution grating spectral data from XMM-Newton satellite (WAX-I). Here we discuss the global dynamical properties as well as the…
We review the main results from several radio, X-ray and multi-frequency surveys on the topic of cosmological evolution of BL Lacertae objects. Updated findings on BL Lac evolution following the recent identification of many sources in the…
We present long-slit integrated spectroscopy of 238 late-type galaxies belonging to the Herschel Reference Survey, a volume limited sample representative of the nearby universe. This sample has a unique legacy value since ideally defined…
Bright and eclipsing, the high-mass X-ray binary Vela X-1 offers a unique opportunity to study accretion onto a neutron star from clumpy winds of O/B stars and to disentangle the complex accretion geometry of these systems. In Chandra-HETGS…
Accretion onto SMBH is believed to occur mostly in obscured AGN. Such objects are proving rather elusive in surveys of distant galaxies, including those at X-ray energies. Our main goal is to determine whether the revised IRAC criteria of…
We present near-IR photometry and imaging observations of a small sample of sources identified in the BeppoSAX 5-10 keV survey (HELLAS) which resolves ~ 20-30% of the X-ray background at these energies. The near-IR data are combined with…
In this paper we further explore the implications that this has for the currently popular consensus that it is the orientation of the circumnuclear obscuring torus which determines whether absorption is present along our sight-line. The…
We report on a detailed analysis of the correlation between the optical-UV (Lo) and X-ray (Lx) luminosities of quasars by means of Monte Carlo simulations, using a realistic luminosity function. We find, for a quasar population with an…
The high-frequency-peaked BL Lac, MS0205.7+3509 was observed twice with XMM-Newton. Both X-ray spectra are synchrotron-dominated, with mean 0.2--10keV fluxes of 2.80+/-0.01 and 3.34+/-0.02 E-12 erg/cm^2/s. The X-ray spectra are well fit by…
We present a detailed study of the stellar mass vs. specific angular momentum (AM) relation (Fall relation) for a representative sample of 564 nearby galaxies in the eXtended GALEX Arecibo SDSS Survey (xGASS). We focus on the dependence of…
We present X-ray spectral analysis of five Chandra and XMM-Newton observations of the gravitationally-lensed blazar PKS1830-211 from 2000 to 2004. We show that the X-ray absorption toward PKS1830-211 is variable, and the variable absorption…
Recent quasar microlensing observations have constrained the X-ray emission sizes of quasars to be about 10 gravitational radii, one order of magnitude smaller than the optical emission sizes. Using a new ray-tracing code for the Kerr…
We present an analysis of the spectral properties observed in X-rays from active galactic nucleus BL Lacertae using RXTE, Suzaku, ASCA, BeppoSAX, and Swift observations. The total time covered by these observations is approximately 20…
Strong gravitational lensing offers constraints on the Hubble constant that are independent of other methods. However, those constraints are subject to uncertainties in lens models. Previous studies suggest that using an elliptical power…
Light bending due to strong gravity has recently been invoked to explain variability and flux correlations between different bands in some accreting black holes. A characteristic feature of light bending is reflection-dominated spectra,…
Weak spectral features in BL Lacertae objects (BL Lac) often provide a unique opportunity to probe the inner region of this rare type of active galactic nucleus. We present a Hubble Space Telescope/Cosmic Origins Spectrograph observation of…
We report on spectroscopic observations covering most of the 475 BL Lacs in the 2nd Fermi LAT catalog of AGN. Including archival measurements (correcting several erroneous literature values) we now have spectroscopic redshifts for 44% of…
We present XMM-Newton observations of four BL Lac objects (1H1219+301, H1426+428, Markarian 501 and PKS 0548-322), which have been found with past X-ray missions to contain evidence of broad soft X-ray absorption features. Observations with…
Hydrogen column densities inferred from X-ray absorption are typically 5 - 30 times larger than the neutral atomic hydrogen column densities derived from 21cm HI absorption toward radio-loud active galactic nuclei. Some part of the…
(abridged) In this paper, we examined XMM Newton EPIC spectra of 14 ultra-luminous X-ray sources (ULXs)in addition to the XMM RGS spectra of two sources (Holmberg II X-1 and Holmberg IX X-1). We determined oxygen and iron abundances of the…