Related papers: Polarization of AGN in UV Spectral Range
Deep surveys of the cosmic X-ray background are reviewed in the context of observational progress enabled by the Chandra X-ray Observatory and the X-ray Multi-Mirror Mission-Newton. The sources found by deep surveys are described along with…
Ultra-fast outflows (UFO) appear to be common in local active galactic nuclei (AGN) and may be powerful enough ($\dot{E}_{kin}$$\geq$1\% of L$_{bol}$) to effectively quench the star formation in their host galaxies. To test feedback models…
We present a study of the effects of ultraviolet (UV) emission from active galactic nuclei (AGN) on the atmospheric composition of planets and potential impact on life. It is expected that all supermassive black holes, which reside at…
Many upcoming surveys, particularly in the radio and optical domains, are designed to probe either the temporal and/or the spatial variability of a range of astronomical objects. In the light of these high resolution surveys, we review the…
The recent compilation of quasar (QSO) X-ray and UV flux measurements include QSOs that appear to not be standardizable via the X-ray luminosity and UV luminosity ($L_X-L_{UV}$) relation and so should not be used to constrain cosmological…
Light emission from galaxies exhibit diverse brightness profiles, influenced by factors such as galaxy type, structural features and interactions with other galaxies. Elliptical galaxies feature more uniform light distributions, while…
The narrow emission line luminosities of radio-loud AGN are well-correlated with their low-frequency radio luminosities. This correlation is linear and extends over at least four orders of magnitude. The correlation is discussed in terms of…
Little is presently known about the nature of ultraluminous X-ray sources (ULX). Different hypotheses have been proposed to explain their properties: intermediate-mass BHs, Kerr BHs, young SNR, or background AGN. Some of the current…
In this article we present different aspects of AGN studies demonstrating the importance of the UV spectral range. Most important diagnostic lines for studying the general physical conditions as well as the metalicities in the central broad…
We will briefly discuss the importance of sensitive X-ray observations above a few tens of keV for a better understanding of the physical mechanisms associated to the Supermassive Black Hole primary emission in both radio quiet and radio…
We review results from our monitoring observations of several lensed quasars performed in the optical, UV, and X-ray bands. Modeling of the multi-wavelength light curves provides constraints on the extent of the optical, UV, and X-ray…
We present the expected X-ray polarization signal resulting from distant reprocessing material around black holes. Using a central isotropic power-law emission at the center of the simulated model, we add distant equatorial and axially…
Population of levels of the hyperfine and fine split ground state of an atom is affected by radiative transitions induced by anisotropic radiation flux. Such aligned atoms precess in the external magnetic field and this affects properties…
We analyze the X-ray properties for a sample of 23 high probability AGN candidates with ultraviolet variability identified in Wasleske et al. (2022). Using data from the Chandra X-ray Observatory and the XMM-Newton Observatory, we find…
We propose that the X--ray emission from radio quiet AGN and galactic black holes is due to Comptonization of soft thermal photons emitted by the underlying accretion disk in localized structures (blobs). The power per unit area produced by…
Absorption signatures in the spectra of QSOs are one of our most powerful tools for studying galactic and intergalactic environments at high redshifts. With the discovery of QSOs out to z > 7, QSO absorption lines are now tracing the end…
Ultraluminous X-ray sources (ULX) are off-nuclear point sources in nearby galaxies whose X-ray luminosity exceeds the theoretical maximum for spherical infall (the Eddington limit) onto stellar-mass black holes. Their luminosity ranges from…
We have assembled a sample of 5 X-ray and submm-luminous z~2 QSOs which are therefore both growing their central black holes through accretion and forming stars copiously at a critical epoch. Hence, they are good laboratories to investigate…
I describe the capabilities of the Cosmic Origins Spectrograph, scheduled for May 2009 installation on the Hubble Space Telescope. With a factor-of-ten increase in far-UV throughput for moderate resolution spectroscopy, COS will enable a…
The majority of the highest energy cosmic rays are thought to be electrically charged: protons or nuclei. Charged particles experience angular deflections as they pass through galactic and extra-galactic magnetic fields. As a consequence…