相关论文: Multiwavelength analysis as a probe of accretion a…
We present results from a high resolution X-ray imaging study of nearby LINERs observed by Chandra. This study complements and extends previous X-ray studies of LINERs, focusing on the under-explored population of nearby dust-enshrouded…
Ionization cones and relativistic jets give us one of the most large-scale example of active galactic nuclei (AGN) influence on the surrounding gas environment in galaxies and beyond. The study of ionization cones makes it possible not only…
Compact radio cores in radio-loud active galactic nuclei (AGNs) are classical targets of Very-Long-Baseline interferometric (VLBI) research. Until today little has been known about their X-ray properties in comparison to radio-quiet AGNs.…
The results of Chandra snapshot observations of 11 LINERs (Low-Ionization Nuclear Emission-line Regions), three low-luminosity Seyfert galaxies, and one HII-LINER transition object are presented. Our sample consists of all the objects with…
We present a new tool for the analysis of the optical emission lines of the gas in the Narrow Line Region (NLR) around Active Galactic Nuclei (AGNs). This new tool can be used in large samples of objects in a consistent way using different…
The central engines of Active Galactic Nuclei (AGNs) are powered by accreting supermassive black holes, and while AGNs are known to play an important role in galaxy evolution, the key physical processes occur on scales that are too small to…
Observations at high energies yield important information on the structure and nature of AGN; when coupled with deep optical and near-infrared (photometric and spectroscopic) follow-up, they provide constraints on the mass of the growing…
Mid-infrared diagnostics are presented for a large portion of the Spitzer Infrared Nearby Galaxies Survey (SINGS) sample plus archival data from the Infrared Space Observatory and the Spitzer Space Telescope. Our main result is that these…
The detailed workings of the central engines of powerful quasars remain a mystery. This is primarily due to the fact that, at their cosmological distances, the inner regions of these quasars are spatially unresolvable. Reverberation mapping…
Spectral features can arise by reflection of coronal X-rays on a black hole accretion disc. The resulting profile bears various imprints of strong gravitational field acting on the light emitting gas. The observed shape of the reflection…
The cores of active galactic nuclei (AGN) harbor some of the most extreme conditions of matter and energy in the Universe. One of the major goals of high-energy astrophysics is to probe these extreme environments in the vicinity of…
Spectral energy distributions (SEDs) from X-ray to far-infrared (FIR) wavelengths are presented for a sample of 1246 X-ray luminous active galactic nuclei (AGN; $L_{0.5-10\rm{keV}}>10^{43}$ erg s$^{-1}$), with $z_{\rm{spec}}<1.2$, selected…
LINERs exist in the nuclei of a large fraction of luminous galaxies, but their connection with the AGN phenomenon has remained elusive. We present Hubble Space Telescope narrowband [O III]5007 and H-alpha+[N II] emission-line images of the…
In this work we investigate the properties of the broad emission line components in the Balmer series of a sample of Type 1 Active Galactic Nuclei (AGN). Using the Boltzmann Plot method as a diagnostic tool for physical conditions in the…
We present new XMM-Newton observations of two luminous and high accretion-rate radio-quiet active galactic nuclei (AGNs) at z~2. Together with archival X-ray and rest-frame optical spectra of three sources with similar properties as well as…
With their relatively fast variability time-scales, Galactic X-ray binaries provide an excellent laboratory to explore the physics of accretion and related phenomena, most notably outflows, over different regimes. After comparing the…
We study the X-ray properties of LINER sources with definite detection of a broad H(alpha) emission line in their optical spectra, LINER 1s from Ho et al. sample. These objects preferentially harbor a low luminosity active nucleus at the…
The broad-line region (BLR) of active galactic nuclei (AGNs) traces gas close to the central supermassive black hole (BH). Recent reverberation mapping (RM) and interferometric spectro-astrometry data have enabled detailed investigations of…
We briefly describe some recent observational results, mainly at X-ray wavelengths, on the winds of luminous active galactic nuclei (AGNs). These winds likely play a significant role in galaxy feedback. Topics covered include (1) Relations…
In this paper we study the nuclear obscuration of galaxies hosting LINERs based on their X-ray and optical emission. They show column densities (N_H) at soft energies (0.5-2 keV) mostly related to the diffuse emission around the AGN,…