نتایج جستجو برای: AGN
تعداد نتایج: 7335 فیلتر نتایج به سال:
We review the variety of Active Galactic Nuclei (AGN) classes (so-calledAGN zoo") and classification schemes of galaxies by activity types based on their optical emission-line spectrum, as well as other parameters and other than optical wave-length ranges. A historical overview of discoveries of various types of active galaxies is given, including Seyfert galaxies, radio galaxies, QSOs, BL Lace...
Discovery of 10 µm silicate emission in quasars. Evidence of the AGN unification scheme. Abstract. According to the unified scheme, AGN are surrounded by a dust-torus, and the observed diversity of AGN properties results from the different orientations relative to our line of sight. The strong resonance of silicate dust at 10 µm is therefore, as expected, seen in absorption towards many type-2 ...
The smooth soft X-ray excess seen in many type-1 AGN can be well described by models of absorption in partially ionized material with a large velocity dispersion, often physically interpreted as a radiatively driven accretion disk wind. However, the stateof-the-art XSCORT code, which calculates the photoionized radiative transfer through a differentially outflowing absorber, shows that terminal...
We examine the relationship between star formation and AGN activity by constructing matched samples of local (0 < z < 0.6) radio-loud and radio-quiet AGN in the HerschelATLAS fields. Radio-loud AGN are classified as high-excitation and low-excitation radio galaxies (HERGs, LERGs) using their emission lines and WISE 22-μm luminosity. AGN accretion and jet powers in these active galaxies are trac...
Morphologies of z∼0.7 AGN Host Galaxies in CANDELS: No trend of merger incidence with AGN luminosity
The processes that trigger Active Galactic Nuclei (AGN) remain poorly understood. While lower luminosity AGN may be triggered by minor disturbances to the host galaxy, stronger disturbances are likely required to trigger luminous AGN. Major wet mergers of galaxies are ideal environments for AGN triggering since they provide large gas supplies and galaxy scale torques. There is however little ob...
Galaxy interactions are thought to be one of the main triggers of Active Galactic Nuclei (AGN), especially at high luminosities, where the accreted gas mass during the AGN lifetime is substantial. Evidence for a connection between mergers and AGN, however, remains mixed. Possible triggering mechanisms remain particularly poorly understood for luminous AGN, which are thought to require triggerin...
Current X-ray observatories, archival X-ray data, and the Sloan Digital Sky Survey (SDSS) represent a powerful combination for addressing key questions about active galactic nuclei (AGN). We describe a few selected issues at the forefront of X-ray AGN research and the relevance of the SDSS to them. Bulk X-ray/SDSS AGN investigations, X-ray weak AGN, red AGN, hard X-ray selected AGN, high-redshi...
acute glomerulonephritis (agn) is a type of renal disease which indicates the inflammation of glomerulus and nephrons. this study was carried on 94 children, <15 years old with the diagnosis of agn who were admitted to qom and yazd's hospitals between 2000 and 2006. data were collected using hospital records on admission, progression notes and outpatient follow up. among 94 patients, 55.3% were...
A key question in extragalactic studies is the determination of the relative roles of stars and AGN in powering dusty galaxies at z∼ 1-3 where the bulk of star-formation and AGN activity took place. In Paper I, we present a sample of 336 24μm-selected (Ultra)Luminous Infrared Galaxies, (U)LIRGs, at z ∼ 0.3-2.8, where we focus on determining the AGN contribution to the IR luminosity. Here, we us...
We study the host galaxies and black holes of typical X-ray selected AGN at intermediate redshifts (z ∼ 0.5− 1.4). The AGN are selected such that their spectral energy distributions are dominated by stellar emission, i.e., they show a prominent 1.6 μm bump thus minimizing the AGN emission contamination. This AGN population comprises approximately 50% of the X-ray selected AGN at these redshifts...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید