Results 121 to 130 of about 6,292 (222)
Radio Emission from High-redshift Active Galactic Nuclei in the JADES and CEERS Surveys
The Astronomical JournalRecent calculations indicate that radio emission from quasars at z ∼ 6–7 could be detected at much earlier stages of evolution, at z ∼ 14–15, by the Next-Generation Very Large Array (ngVLA) and the Square Kilometer Array (SKA).
Muhammad A. Latif +2 more
doaj +1 more source
The ‘harder when brighter’ X-ray behaviour of the low-luminosity active galactic nucleus NGC 7213
, 2012 We present the first robust evidence of an anticorrelation between the X-ray photon index, Γ, and the X-ray luminosity in a single low-luminosity active galactic nucleus (LLAGN), NGC 7213.
Uttley, P. +5 more
core +2 more sources
The Astrophysical JournalHow a seemingly “dead” host galaxy provides fuel for its active galactic nucleus (AGN) remains an unresolved problem. Using the Five-hundred-meter Aperture Spherical radio Telescope (FAST), we present a new high-sensitivity atomic-hydrogen (H i ...
Jin-Long Xu +6 more
doaj +1 more source
Strongly Magnetized Accretion with Low Angular Momentum Produces a Weak Jet
The Astrophysical JournalWe study the spherical accretion of magnetized plasma with low angular momentum onto a supermassive black hole, utilizing global general relativistic magnetohydrodynamic simulations.
Alisa Galishnikova +4 more
doaj +1 more source
The optical luminosity function of quasars and low-luminosity active galactic nuclei
The Astronomical Journal, 1987 The optical luminosity function derived from quasars with M(B) less than -23 is extended to include the nuclear luminosities of Seyfert 1 galaxies. The model is fitted to the (total) luminosity data for active galaxies from a complete flux-limited survey.
openaire +1 more source
, 2005 Contains fulltext : 32902.pdf ( ) (Open Access) Contains fulltext : 32902.pdf (Publisher’s version ) (Open Access)We present the completed results of a high resolution radio imaging ...
Wilson, AS +8 more
core +1 more source
DUST IN ACTIVE GALACTIC NUCLEI: ANOMALOUS SILICATE TO OPTICAL EXTINCTION RATIOS?
, 2014 Dust plays a central role in the unification theory of active galactic nuclei (AGNs). However, little is known about the nature (e.g., size, composition) of the dust that forms a torus around the AGN. In this Letter, we report a systematic exploration of
Lyu, Jianwei, Hao, Lei, Li, Aigen
core
The hard X-ray luminosity function of high-redshift (3 < z ≲ 5) active galactic nuclei
, 2014 We present the hard-band (2-10 keV) X-ray luminosity function (HXLF) of 0.5-2 keV band selected active galactic nuclei (AGN) at high redshift. We have assembled a sample of 141 AGN at 3 = 23 to be 0.54 ± 0.05, with no strong dependence on luminosity ...
Comastri, A. +17 more
core +1 more source
Ensemble Variability Properties of Active Galactic Nuclei in the SDSS DR17
The Astrophysical JournalWe present the results from a study of ∼9600 broadline-selected active galactic nuclei (AGNs) with host galaxies detected from the Sloan Digital Sky Survey (SDSS) Data Release 17.
Krittapas Chanchaiworawit +1 more
doaj +1 more source
Spectroscopical confirmation of variability-selected active galactic nuclei
, 2004 The cosmological evolution of active galactic nuclei (AGN) luminosity function is poorly known at the faint end, since active nuclei fainter than their host galaxies cannot be selected by color techniques.
Vagnetti, F +6 more
core