Related papers: Seyfert's Sextet: where is the gas?
The Seyfert galaxy NGC 1275 is the central, dominant galaxy in the Perseus cluster of galaxies. NGC1275 is known as a powerful source of radio and X-ray emission. The well-known extragalactic object NGC 1275 has been observed by the SHALON…
We report the detection of both soft and hard excess X-ray emission in the cluster of galaxies A 2199, based upon spatially resolved spectroscopy with data from the BeppoSAX, EUVE and ROSAT missions. The excess emission is visible at radii…
The existence of ionized X-ray absorbing layers of gas along the line of sight to the nuclei of Seyfert galaxies is a well established observational fact. This material is systematically outflowing and shows a large range in parameters.…
We carried out deep mapping observations of the atomic hydrogen (HI) 21 cm line emission in a field centered on the famous galaxy group Stephan's Quintet (SQ), using the Five-hundred-meter Aperture Spherical Telescope (FAST) equipped with…
We detect four isolated, X-ray over-luminous (Lx>2e43 [h/0.5]**-2 erg/s) elliptical galaxies (OLEGs) in our 160 square degree ROSAT PSPC survey. The extent of their X-ray emission, total X-ray luminosity, total mass, and mass of the hot gas…
Compact group galaxies often appear unaffected by their unusually dense environment. Closer examination can, however, reveal the subtle, cumulative effects of multiple galaxy interactions. Hickson Compact Group (HCG) 59 is an excellent…
In this paper we report on the first simultaneous optical and X-ray (Beppo-SAX) observations of the radio-quiet AGN 1H0419-577. The optical spectrum clearly leads us to classify this source as a Seyfert 1. The X-ray spectrum is, however,…
We present a series of statistical tests done to a sample of 29 Seyfert 1 and 59 Seyfert 2 galaxies selected from mostly isotropic properties, their far infrared fluxes and warm infrared colors. Such selection criteria provide a profound…
We present the results of a Hubble Space Telescope (HST) survey of extended [OIII] emission in a sample of 60 nearby Seyfert galaxies (22 Seyfert 1's and 38 Seyfert 2's), selected by mostly isotropic properties. The comparison between the…
We present an analysis of the X-ray spectra of a sample of 37 observations of 26 Seyfert galaxies observed by XMM-Newton in order to characterize their iron K emission. All objects show evidence for iron line emission in the 6-7 keV band. A…
We present optical spectroscopic observations of 93 galaxies taken from the infra-red selected COLA (Compact Objects in Low Power AGN) sample. The sample spans the range of far-IR luminosities from normal galaxies to LIRGs. Of the galaxies…
We present a systematic study of the diffuse hot gas around early-type galaxies (ETGs) residing in the Virgo cluster, based on archival {\it Chandra} observations. Our representative sample consists of 79 galaxies with low-to-intermediate…
We have conducted a systematic study of X-ray emission from ultra-compact dwarf (UCD) galaxies and extended star clusters (ESCs), based on archival {\sl Chandra} observations. Among a sample of 511 UCDs and ESCs complied from the…
The Seyfert 1 galaxy 1H 0419-577 hosts a $\sim$kpc extended outflow that is evident in the [\ion{O}{iii}] image and that is also detected as a warm absorber in the UV/X-ray spectrum. Here, we analyze a $\sim$30 ks Chandra-ACIS X-ray image,…
The Fermi/LAT collaboration recently reported the detection of starburt galaxies in the high energy gamma-ray domain, as well as radio-loud narrow-line Seyfert 1 objects. Motivated by the presence of sources close to the location of…
Hot gas dominates the emission in X-ray luminous early-type galaxies, but in relatively X-ray faint systems, integrated X-ray emission from discrete stellar-like sources is thought to be considerable, although the amount of the contribution…
We present a study of the diffuse ionized gas (DIG) in three Sculptor group galaxies: NGC 55, NGC 253, and NGC 300. The study is based on narrow band imagery in H-alpha+[NII](6548+6583A) and [SII] (6717+6731A). We find that DIG contributes…
An optical spectropolarimetric study has shown that the detectability of polarised broad H-alpha in Seyfert 2 galaxies is correlated to the IRAS f60/f25 flux ratio where only those Seyfert 2s with "warm" IRAS colours show polarised broad…
The excellent soft X-ray sensitivity of the PSPC detector onboard the ROSAT satellite provided the first chance to study precisely the spectral and timing properties of Narrow-Line Seyfert 1 galaxies. ROSAT observations of Narrow-Line…
UGC 3995 is a close pair of spiral galaxies whose eastern component hosts a Seyfert 2 nucleus. We present a detailed analysis of this system using long slit spectroscopy and narrow (\ha + \nii) as well as broad band (B, R) imaging and an…