... RATAN-600 data for the BL Lacertae objects (multi-frequency catalogue, Version 1.0) . GPS radio sources . ... BL Lacertae objects . ... The difference between these objects is the peak frequency of the synchrotron component of their spectral energy distribution (HBLs: high-energy peak, LBLs: low-energy peak, IBLs: intermediate). ... The observations were carried out with the RATAN-600 radio telescope during 2006-2011 at six frequencies: 1.1, 2.3, 4.8, 7.7, 11.2 and 21.7 GHz. ...

We present ultraviolet, optical, near-infrared, Spitzer mid-infrared, and radio images of 14 radio-selected objects in M33. ... We have detected the majority of cluster candidates in M33 at all wavelengths. ... These results suggest that 11 of the 14 radio-selected objects are optically visible young star clusters with a surrounding H II region, that 2 are background objects, possibly active galactic nuclei (AGNs), and that 1 is a Wolf-Rayet star with a surrounding H II region. ...

Unlike at lower redshift, where there is a 40% detection rate, surveys for 21-cm absorption arising within the hosts of z 1 radio galaxies and quasars have been remarkably unsuccessful. ... In order to find this "missing" gas at high redshift, we have therefore undertaken a survey of z 2 radio sources, selected by optical faintness. ... The possibility that the other five could be located at lower photon rates cannot be ruled out, although zero detections out of five is not statistically significant. ...

... Armagh Observatory, College Hill, Armagh BT61 9DG, +44 (0)28 3752 2928 . ... Risks Comparable to NEOs . ... The Increasing Rate of Discovery of Asteroids . ... Comet and Asteroid Collision Probabilities . ... Extreme albedo comets and the impact hazard (PDF Format) . ... Asteroid Impact Animations . ... Workshop on Scientific Requirements for Mitigation of Hazardous Comets and Asteroids - 2002 . ... The Spaceguard Survey Report, 1992 (PDF) . Tsunami from Asteroid/Comet Impacts . ...

... During the analysis of the surveys carried out on RATAN-600, it was found that almost one fifth of the detected sources shows significant radio flux variations. ... We used the data from "Cold" radio surveys carried out with RATAN-600 in 1980-1994 to search for radio sources with significant flux variability. ... On possibility of detection of variable sources using the data of Cold surveys carried out on RATAN-600. ... Detection of Variable Sources Using the Data of "Cold" Surveys. ...

M1 image More About M1 Nice Color Picture . ... M16 image More About M16 HST image . ... M31 image More About M31 Nice Color Picture . ... M42 image ; M43 image More About M42/43 Nice Color CCD Picture . M51 image More About M51 Color Image of M51 M51 Supernova . M57 image More About M57 Nice Color CCD Picture Very Deep M57 Image . ... M81 image More About M81 M81 Supernova Ultraviolet Image of M81 More about Ultraviolet Imaging . M82 image More About M82 M82 False Color M82 True Color . ...

... Credit: Data - Hubble Legacy Archive , ESA , NASA ; Processing - Al Kelly Explanation: Active galaxy NGC 1275 is the central, dominant member of the large and relatively nearby Perseus Cluster of Galaxies . Wild-looking at visible wavelengths, the active galaxy is also a prodigious source of x-rays and radio emission. ... Publications with keywords: NGC 1275 - Perseus A - Perseus cluster - active galaxy - magnetic field - X-ray - radio emission - multiwavelength - HST . ...

... 2001 August 16 . Centaurus A: X-Rays from an Active Galaxy . ... CXO , NASA . ... Astronomers were not disappointed, as Centaurus A's appearance in x-rays makes its classification as an active galaxy easy to appreciate. ... Blasting toward the upper left corner of the picture, the jet seems to arise from the galaxy's bright central x-ray source -- suspected of harboring a black hole with a million or so times the mass of the Sun. ... About APOD | ... NASA Technical Rep.: ...

... LABORATORY OF RADIO ASTRONOMICAL OBSERVATIONS . Radio sources identification is one of the most important tasks of the current radio astrophysics. ... Optical idetification. ... Optical identifications of subsample of steep spectra radio sources from RC catalog using 6m SAO telescope of SAO RAS: optical observations. ... Astronomy Reports. ... Identification of radio sources with data of various radio catalogs allows one to construct continual spectrum of the object and its radio structure. ...

. Authors: A.A. Suchkov , V.A. Marakov . Journal: Pis'ma Astron. Zh., 1976, v.2, p.38-385. Metallisity function of globular clusters in the Galaxy is constructed. It is found to have three "humps". This leads to a conclusion that there were three metal enrichment outbursts during the period of globular cluster formation. The constraints on the nature of metal sourses and on the early evolution of Galaxy are considered.

... Science . ... Science Users Information > Science Publications > Science Announcements > Clustering Measurements of Active Galactic Nuclei . ... Observing Facilities . ... ESO Data . ... Galaxies and active galactic nuclei (AGN) are not randomly distributed in the Universe. ... This ESO workshop, which will be the first ever dedicated workshop on AGN clustering, aims to summarise our current understanding of AGN clustering and how the community should prepare for upcoming data sets and challenges. ...

The FR Divide in Radio Galaxies through Environmental Interactions T. Maciel (Astrophysics Group) tm419@cam.ac.uk , P. Alexander (Astrophysics Group) Radio -Loud Galaxies · Galaxies which are dominated by their radio emission (10MHz -100GHz) and show extended morphology: - Jets Active Galactic Nuclei -Lobes powered by (AGN) -Hotspots -Central black hole -Accretion disc -Strong B fields -Dusty torus Chandra X-Ray image of Perseus cluster with VLA ... Right: FRII galaxy 3C175 at 5GHz. ...

Deep Space Image Index . ... Cartwheel Galaxy ( GIF , 299K; JPEG , 62K; caption ) . NGC1850 - Tale of Two Clusters ( GIF , 255K; JPEG , 117K; caption ) . Cat's Eye Nebula ( GIF , 113K; TIF , 1M; caption ) . Ring Structure Around Supernova 1987A ( TIF , 2M; caption ) . 30 Doradus Nebula ( GIF , 379K; caption ) . Eta Carinae Star ( GIF , 433K; caption ) . Cygnus Loop Supernova Blast Wave ( TIF , 4M; caption ) . Spiral Galaxy M51 ( TIF , 769K; caption ) . ...

... Structure of Data . ... Catalog . ... In SAI OCL Catalog, we introduce our work on investigation of the Milky Way system of open star clusters. The main goal of our study is a search for new clusters using huge surveys. 168 new clusters have been already discovered by us using J,H,Ks data from 2MASS point source catalog. ... For 141 new clusters, we found their physical parameters using J,H,Ks data from 2MASS catalog and, for a number of clusters, our UBVRI CCD observational magnitudes. ...

The Variable Gamma-Ray Source 2CG 135+01 ApJ, 497:L89-L91, 1998 7 h gamma AGN variability . gamma-radio-AGN-variability ADS query . ... Model for the High-Energy Emission from Blazars 1993ApJ.. ... Possible Production of High-Energy Gamma Rays from Proton Acceleration in the Extragalactic Radio Source Markarian 501 astro-ph/9803241 K.Mannheim . ... A theoretical unifying scheme for gamma-ray bright blazars astro-ph/9807317 G. Ghisellini, A. Celotti, G. Fossati, L. Maraschi, A. Comastri . ...

... In one situation, we can use light from quasars to probe the material between us and them because that light may pass through one or more galaxies or gas clouds on its way to us. The gas inside the galaxies or the intergalactic clouds acts then as a filter, absorbing selected wavelengths from the quasar light. ... Light from a quasar must pass through clouds of gas and even faint galaxies -- each leaving its imprint on the light -- before we receive it here on Earth. ... Gravitational lensing . ...

... Posts tagged ?source detection? ... wavdetect is a wavelet-based source detection algorithm that is in wide use in X-ray data analysis, in particular to find sources in Chandra images. ... In Spring 2006, SAMSI (Statistical and Applied Mathematical Sciences Institute) program on Astrostatistics began with tutorials, followed by workshops and regular meetings of working groups ( Exoplanets, Surveys and Population Studies, Gravitational Lensing, Source Detection and Feature Detection, Particle Physics...

An X-ray/radio sample of Active Galactic Nuclei Nuria Fonseca Bonilla Tutor: Stefano Bianchi Matteo Guainazzi An X-ray/radio sample of Active Galactic Nuclei Brief introduction Results Conclusions An X-ray/radio sample of Active Galactic Nuclei 1. ... Classification of AGN radio loud (powerful jets): e.g: radio galaxies, quasars, blazars... radio quiet radio quiet quasars (RQQs) Veron `06: MABS < -23 Seyfert Veron `06: MABS > -23 An X-ray/radio sample of Active Galactic Nuclei 3. ...

... The hard gamma radiation from AGN is produced most probably in the relativistic jets observed in the considerable part of these objects. In the center of AGN (and may be of all other galaxies) there is a supermassive black hole surrounded by the accretion disk, which is the source of the energy in these objects. ... The problem of particle acceleration in the AGN jets is very important: the time of the electron energy losses in the jets is usually much less than their life time. ... next page . ...

USING THE CORRELATION BETWEEN ISGRI SURVEY RESULTS AND OTHER CATALOGUES TO AID SOURCE IDENTIFICATION John B. Stephen, A. Malizia and L. Bassani IASF-INAF, Via P. Gobetti 101, 40129 Bologna, ITALY, E-mail: stephen@iasfbo.inaf.it ABSTRACT In order to help in the identification of INTEGRAL/ISGRI sources, we have developed a software package which allows a rapid and detailed cross-correlation to be performed between various source catalogues. ... We show below some preliminary results from this analysis. ...