搜索结果: 1-15 共查到“天文学 AGNs”相关记录16条 . 查询时间(0.063 秒)
The complete census of optically selected AGNs in the Coma Supercluster: the dependence of AGN activity on the local environment
Galaxies: clusters: individual: Coma Galaxies evolution Galaxies nuclei
2011/10/11
To investigate the dependence of the occurrence of active galactic nuclei (AGNs) on local galaxy density, we study the nuclear properties of ~5000 galaxies in the Coma Supercluster whose density spans...
Off-Axis Energy Variability of AGNs: a New Paradigm for Broad-Line- and Continuum-Emitting Regions
accretion, accretion disks—black hole physics—galaxies: active— galaxies: Seyfert — polarization — quasars: emission lines
2011/10/17
The general picture of how thermal AGNs work has become clearer in recent years but major observational puzzles threaten to undermine this picture. These puzzles include AGNs with extremely asymmetric...
Evolution and Distribution of Magnetic Fields from AGNs in Galaxy Clusters II. The Effects of Cluster Size and Dynamical State
Galaxy Clusters Effects Cluster Size Dynamical State
2011/10/9
Theory and simulations suggest that magnetic fields from radio jets and lobes powered by their central super massive black holes can be an important source of magnetic fields in the galaxy clusters. T...
Particle Acceleration by Magnetic Reconnection in AGNs and in the IGM
Particle Acceleration Magnetic Reconnection AGNs IGM
2011/10/9
There is no single mechanism by which fast particles are accelerated in astrophysical environments, and it is now recognized that the data require a rich variety of different mechanisms operating unde...
New Method for Exploring Super-Eddington AGNs by Near-infrared Observations
accretion: accretion disc—black hole physics— galaxies:active
2011/10/8
We propose a new method to explore the candidate super-Eddington active galactic nuclei (AGNs). We examine the properties of infrared (IR) emission from the inner edge of the dusty torus in AGNs, whic...
Synchrotron radio emission in radio-quiet AGNs
Synchrotron radio emission radio-quiet AGNs
2011/1/11
The basic mechanism responsible for radio emission in radio-loud active galactic nuclei (AGNs) is assumed to be synchrotron radiation. We suggest here that radio emission in radio-quiet objects is als...
The Spatial Clustering of ROSAT All-Sky Survey AGNs II. Halo Occupation Distribution Modeling of the Cross Correlation Function
The Spatial Clustering ROSAT All-Sky Survey AGNs II
2011/1/11
This is the second paper of a series that reports on our investigation of the clustering properties of AGNs in the ROSAT All-Sky Survey (RASS) through cross-correlation functions (CCFs) with Sloan Dig...
The Wide Field X-ray Telescope (WFXT) is a proposed mission with a high survey speed, due to the combination of large field of view (FOV) and effective area, i.e. grasp, and sharp PSF across the whole...
The orientation of the nuclear obscurer of the AGNs
galaxies statistics — galaxies Seyfert — galaxies nuclei — galaxies spiral
2010/11/15
We examine the distribution of axis ratios of a large sample of disk galaxies hosting type 2 AGNs selected from the Sloan Digital Sky Survey and compare it with a well-defined control sample of non-ac...
The quasar SDSS J142507.32+323137.4 : dual AGNs?
galaxies active — galaxies individual (SDSS J142507.32+323137.4) —quasars emission lines
2010/11/16
We analyze the optical spectrum of type 1 QSO SDSS J1425+3231. This object is interesting since its narrow emission lines such as [O III]4959, 5007 are doublepeaked,and the line structure can be mod...
Evolution and Distribution of Magnetic Fields from AGNs in Galaxy Clusters. I. The Effect of Injection Energy and Redshift
galaxies active — galaxies clusters general — methods numerical — MHD — turbulence
2010/11/9
We present a series of cosmological magnetohydrodynamic (MHD) simulations that simultaneously follow the formation of a galaxy cluster and evolution of magnetic fields ejected by an Active Galactic Nu...
On the Origin of Ultraviolet Emission and the Accretion Model of Low-luminosity AGNs
accretion accretion disks — black hole physics — galaxies active — quasars general — Ultraviolet general
2010/11/12
Low-luminosity active galactic nuclei (LLAGNs) are generally believed to be powered by an inner radiatively inefficient, advection-dominated accretion flow (ADAF), an outer truncated thin disk, and a ...
Constraining halo occupation properties of X-ray AGNs using clustering of Chandra sources in the Bootes survey region
Cosmology and Extragalactic Astrophysics (astro-ph.CO)
2010/12/27
We present the most precise measurement to date of the spatial clustering of X-ray selected AGNs using a sample derived from the Chandra X-ray Observatory survey in the Bootes field. The real-space tw...
The M_BH-M_star relation of obscured AGNs at high redshift
Cosmology and Extragalactic Astrophysics (astro-ph.CO) Galaxy Astrophysics (astro-ph.GA)
2010/12/24
We report the detection of broad Halpha emission in three X-ray selected obscured AGNs at z=1-2. By exploiting the Halpha width and the intrinsic X-ray luminosity, we estimate their black hole masses,...
CAN DOUBLE-PEAKED LINES INDICATE MERGING EFFECTS IN AGNs?
Active Galactic Nucleus DOUBLE-PEAKED LINES
2009/3/16
The influence of merging effects in the central part of an Active
Galactic Nucleus (AGN) on the emission spectral line shapes are discussed. We
present a model of close binary Broad Line Region. The...