Related papers: The ROSAT Wide Field Camera Extragalactic Survey

We present modeling and interpretation of the continuum and emission lines for a sample of 51 unobscured Type 1 active galactic nuclei (AGN). All of these AGNs have high quality spectra from both XMM-Newton and Sloan Digital Sky Survey…

We describe further results of a program aimed to yield ~10^4 fully characterized optical identifications of ROSAT X-ray sources. Our program employs X-ray data from the ROSAT All-Sky Survey (RASS), and both optical imaging and…

We identified Active Galactic Nuclei (AGN) candidates as counterparts to unidentified gamma-ray sources (UGS) from the Fermi-LAT Fourth Source Catalogue at lower Galactic latitudes. Our methodology is based on the use of near- and…

(abridged)The majority of Active Galactic Nuclei (AGN) suffer from significant obscuration by surrounding dust and gas. X-ray surveys in the 2-10 keV band will miss the most heavily-obscured AGN in which the absorbing column density exceeds…

We present the results of our identification of 11 X-ray sources detected on the half of the sky $0^\circ<l<180^\circ$ in the 4-12 keV energy band on the combined map of the first five all-sky surveys with the Mikhail Pavlinsky ART-XC…

The X-ray luminosity function (XLF) of galaxies is dominated by AGN (classified by their optical spectra) above Lx=10**42 erg/s, below this value by normal galaxies. The X-ray flux of AGN at low X-ray luminosity therefore contains…

We use the sample of emission-line nuclei derived from a recently completed optical spectroscopic survey of nearby galaxies to quantify the incidence of local (z = 0) nuclear activity. Consistent with previous studies, we find detectable…

We briefly review and extend our discussion of the ROSAT detection of the extraordinarily luminous (>10^{42} erg/s) partly extended (> 30 kpc diameter) X-ray emission from the double-nucleus ultraluminous infrared galaxy NGC 6240. The ROSAT…

The Six-degree Field Galaxy Survey (6dFGS) is a spectroscopic redshift survey of the Southern hemisphere completed in 2006. While it provides 136,304 spectra of mostly low-redshift galaxies, a large and reliable catalogue of Active Galactic…

We present preliminary results of the analysis of optical spectra of two complementary samples of Seyfert galaxies. The first sample was extracted from a selection of the 4th Fermi Gamma-ray Large Area Telescope (4FGL) catalog, and consists…

Low-ionization nuclear emission-line regions (LINERs), which exist in a large fraction of galaxies, may be the least luminous manifestation of quasar activity. The nature of LINERs has, however, remained controversial because an AGN-like…

We selected 27244 nearby, red, giant early-type galaxies (RGEs) from the Sloan Digital Sky Survey (SDSS). In a large fraction (53%) of their spectra the [O III] emission line is detected, with an equivalent width (EW) distribution strongly…

We present the first spatially resolved analysis of rest-frame optical and UV imaging and spectroscopy for a lensed galaxy at z = 2.39 hosting a Seyfert active galactic nucleus (AGN). Proximity to a natural guide star has enabled high…

We study the utility of broad-band colours in the SkyMapper Southern Survey for selecting Seyfert galaxies at low luminosity. We find that the $u-v$ index, built from the ultraviolet $u$ and violet $v$ filters, separates normal galaxies,…

Aims. We seek a comprehensive analysis of all the information provided by the XMM-Newton satellite of the four Seyfert 1 galaxies ESO 359-G19, HE 1143-1810, CTS A08.12, and Mrk 110, including the UV range, to characterize the different…

Six Narrow-Line Seyfert 1 galaxies have been discovered in optical follow-up spectroscopy of nuclei of galaxies selected for their high X-ray flux in the ROSAT All Sky Survey. We give X-ray and optical parameters of the sources and show…

Zwicky 159.034, one of the Seyfert galaxies identified with EUV sources detected during the ROSAT Wide Field Camera (WFC) all-sky survey, has unusual properties. The ROSAT Position Sensitive Proportional Counter (PSPC) 0.1--2.5 keV X-ray…

RE J2248-511 is one of only 14 non-blazar AGN detected in the far ultraviolet by the ROSAT Wide Field Camera implying a large ultrasoft X-ray flux. This soft X-ray excess is strongly variable on year timescales, a common property of Narrow…

We selected sources with a steep soft-X-ray-band spectrum with a photon index larger than 2.5 -- measured by eROSITA on board the Spectrum-Roentgen-Gamma (SRG) -- from the eFEDS AGN catalogue as candidates of highly accreting supermassive…

We present the second and final data release of the Siding Spring Southern Seyfert Spectroscopic Snapshot Survey (S7). Data are presented for 63 new galaxies not included in the first data release, and we provide 2D emission-line fitting…