Results 91 to 100 of about 8,662 (194)
An accretion disc-corona model for X-ray spectra of active galactic nuclei [PDF]
, 2009 The hard X-ray emission of active galactic nuclei (AGN) is believed to originate from the hot coronae above the cold accretion discs. The hard X-ray spectral index is found to be correlated with the Eddington ratio L(bol)/L(Edd), and the hard X-ray ...
Cao, Xinwu, Xinwu Cao
core +1 more source
Multiple Emission Regions in Jets of the Low-Luminosity Active Galactic Nucleus in NGC 4278
The Astrophysical JournalThe Large High Altitude Air Shower Observatory (LHAASO) has detected very-high-energy gamma rays from the low-ionization nuclear emission-line region galaxy NGC 4278, which has a low-luminosity active galactic nucleus (LLAGN) and symmetric, mildly ...
Samik Dutta, Nayantara Gupta
doaj +1 more source
Simulating supernova feedback in galaxy disks [PDF]
, 2012 In this thesis I examine supernova feedback in hydrodynamical simulations of galaxy disks. Understanding this process entails the numerical evaluation of cooling in radiative shocks, and we present a set of simulations using two widely used numerical ...
CREASEY, PETER,EDWARD +1 more
core
The jet power, radio loudness, and black hole mass in radio-loud active galactic nuclei [PDF]
, 2006 Jet formation is thought to be closely connected with the mass of the central supermassive black hole in active galactic nuclei. The radio luminosity commonly used in investigating this issue is merely an indirect measure of the energy transported ...
Liu, Y, Gu, MF, Jiang, DR
core
Misaligned External Gas Acquisition Boosts Central Black Hole Activities
The Astrophysical JournalOne important question in active galactic nuclei (AGN) is how gas is brought down to the galaxy center. Both internal secular evolution (torque induced by nonaxisymmetric galactic structures such as bars) and external processes (e.g., mergers or ...
Yuren Zhou +8 more
doaj +1 more source
Continuum Reverberation Mapping of 18 Active Galactic Nuclei over 4 Yr
The Astrophysical JournalContinuum reverberation mapping probes the size scale of the optical continuum-emitting region in active galactic nuclei (AGN). The source of this emission has long been thought to originate from the accretion disk, but recent studies suggest the broad ...
Jake A. Miller +6 more
doaj +1 more source
Ultra-high energy cosmic rays and the strongest AGN flares
EPJ Web of Conferences, 2018 We perform an observational test of the hypothesis that ultra-high energy cosmic rays (E > 1020 eV) are accelerated in giant flares of active galactic nuclei (AGN). We use the observations of Fermi LAT during the first 7.4 years of the mission. We select
Pshirkov Maxim, Nizamov Bulat
doaj +1 more source
Black hole masses and Doppler factors of gamma-ray active galactic nuclei [PDF]
, 2004 The sizes of the broad-line regions (BLRs) in gamma-ray active galactic nuclei (AGNs) are estimated from their optical continuum luminosity by using the empirical relation between R-BLR and L-lambda,L-opt.
Fan, ZH, Cao, XW
core
Search for High-excitation Emission Lines from a Quasar-scale Active Nucleus in Arp 220
The Astrophysical JournalThe late-stage galaxy merger and prototypical ultraluminous infrared galaxy (ULIRG) Arp 220 is probed using the JWST Mid Infrared Instrument medium-resolution spectrometer to search for multiple diagnostic active galactic nuclei (AGN) emission lines in ...
Charles E. Goldberg +10 more
doaj +1 more source
Flaring γ-Ray Emission from High Redshift Blazars
Galaxies, 2016 High redshift blazars are among the most powerful objects in the Universe. Although they represent a significant fraction of the extragalactic hard X-ray sky, they are not commonly detected in γ-rays. High redshift ( z > 2 ) objects represent
Monica Orienti +4 more
doaj +1 more source