Related papers: Seyfert galaxies in UZC-Compact Groups
We examine the star formation properties of galaxies with very thin disks selected from the Revised Flat Galaxy Catalog (RFGC). The sample contains 333 ultra-flat galaxies (UFG) at high Galactic latitudes, $|b|>10^{\circ}$, with a blue…
Galaxy clusters are crucial to understanding role of the environment in galaxy evolution. However, due to their rarity, only a limited number of clusters have been identified at $z\gtrsim2$. In this paper, we report a discovery of seven…
We present optical broad band B-I colour maps of a further sample of 10 Seyfert 2 galaxies. In these bands, the contribution from emission lines to the total flux is small, and hence the images predominantly trace the continuum…
We cross correlate Gamma--Ray Bursts and X--Ray selected clusters of galaxies at z\leq0.45. We find a positive 2\sigma signal for the angular cross--correlation function w_{bc}(\theta) on scales \theta\leq 3 deg between short GRBs and…
This study compiles stellar populations and internal properties of ultra-diffuse galaxies (UDGs) to highlight correlations with their local environment, globular cluster (GC) richness, and star formation histories. Complementing our sample…
We present a 3-dimensional study of the local (< 100 kpc) environment of Sy1, Sy2 and Bright IRAS Galaxies. For this purpose we use three galaxy samples (Sy1, Sy2, BIRG) located at high galactic latitudes as well as three control sample of…
Hubble Space Telescope Wide Field Planetary Camera 2 images of Hickson Compact Group 79, Seyfert's Sextet, are presented. Both point sources and extended sources detected on the three WF chips were photometered in four filters: F336W,…
We present the results of ROSAT All-Sky Survey observations of Seyfert and IR-luminous galaxies from the Extended 12 Micron Galaxy Sample and the optically-selected CfA Sample. Roughly half of the Seyferts (mostly Seyfert 1s) have been…
We report the discovery of post-starburst ultra-diffuse galaxies (UDGs), identified through spectroscopic analysis with KCWI at the Keck II Telescope. Our analysis is based on a sample of 44 candidate UDGs selected from the Systematically…
Our understanding of the unification of jetted AGNs has advanced greatly as the size of extragalactic sources increased. In the present paper, based on the large sample of radio sources, we compiled 680 blazars (279 FSRQs and 401 BL Lacs)…
We present a list of 75 isolated late-type dwarf galaxies which have no neighbors with a relative radial velocity difference of less than 500 km/s or projected separations within 500 kpc. These were selected from $\sim$2000 dwarf galaxies…
Although Compact Groups of galaxies (CGs) have been envisioned as isolated extremely dense structures in the Universe, it is accepted today that many of them could be not as isolated as thought. In this work, we study Hickson-like CGs…
(Abbreviated) We assemble a sample composed of 243 nearby Seyfert galaxies with redshifts $z\le 0.05$ to test the unification scheme. The sample contains 94 BLS1s, 44 NLS1s, 36 X-ray absorbed HBLR S2s, 42 X-ray absorbed non-HBLR S2s and 27…
X-ray observations have been made of a sample of 20 classical Cepheids, including two new observations (Polaris and {\it l} Car) reported here. The occurrence of X-ray flux around the pulsation cycle is discussed. Three Cepheids are…
The recent detection of gamma-ray emission from four radio-loud narrow-line Seyfert 1 galaxies suggests that the engine driving the AGN activity of these objects share some similarities with that of blazars, namely the presence of a…
We have systematically analyzed a sample of 13 new and archival ROSAT PSPC observations of compact groups of galaxies: 12 Hickson Compact Groups plus the NCG 2300 group. We find that approximately two-thirds of the groups have extended…
We report on sensitive dual-frequency (1.7 and 5 GHz) European VLBI Network observations of the central region of nine Seyfert galaxies. These sources are among the faintest and least luminous members of a complete sample of nearby (d<22…
From a search of a ~ 2400 square degree region covered by both the SDSS and UKIDSS databases, we have attempted to identify galaxies at z ~ 0.5 that are consistent with their being essentially unmodified examples of the luminous passive…
We measure the distribution of velocity dispersions of groups of galaxies identified in the UZC catalog; we use the distribution to derive the group mass function. We introduce a new method which makes efficient use of the entire magnitude…
We map narrow-line regions (NLRs) of 11 nearby Seyfert 2 galaxies with the optical integral-field spectrograph OASIS mounted at CFHT. We model emission-line profiles of 5 forbidden-line doublets and 2 Balmer lines, correcting for the…