Results 141 to 150 of about 47,541 (242)

Mid-infrared Variability from the Central Point Source as Direct Evidence for Obscured Low-luminosity Nuclear Activity in the Nearby Edge-on Galaxy IC 2207

The Astrophysical Journal
Reliable identification of ongoing nuclear activity in nearby galaxies is challenging when central regions are heavily obscured, especially for low-luminosity active galactic nuclei (AGN) whose emission can also be contaminated by the host galaxy.
Yifei Xiong, Lei Hao, Zhenzhen Li, Hongyan Zhou   +3 more
doaj   +1 more source

VLBI Imaging of Parsec-scale Radio Structures in Nearby Low-luminosity Active Galactic Nuclei

The Astrophysical Journal Supplement Series
We report the results of high-resolution 5 GHz Very Long Baseline Array and European VLBI Network observations of 36 nearby galaxies, an extension of the Legacy e-MERLIN Multi-band Imaging of Nearby Galaxies survey.
Xiaopeng Cheng, Tao An, Willem A. Baan, Ranieri D. Baldi, David R. A. Williams-Baldwin, Bong Won Sohn, Robert Beswick, Ian M. McHardy   +7 more
doaj   +1 more source

Evidence of Feedback Effects in Low-luminosity Active Galactic Nuclei Revealed by JWST Spectroscopy

The Astrophysical Journal Letters
This Letter presents an analysis of the infrared (∼3–28 μ m) spectra extracted from the nuclear ( r  
Lulu Zhang, Chris Packham, Erin K. S. Hicks, Ric I. Davies, Daniel E. Delaney, Francoise Combes, Miguel Pereira-Santaella, Almudena Alonso-Herrero, Claudio Ricci, Omaira González-Martín, Laura Hermosa Muñoz, Ismael García-Bernete, Cristina Ramos Almeida, Dimitra Rigopoulou, Fergus R. Donnan, Enrica Bellocchi, Nancy A. Levenson, Martin J. Ward, Santiago García-Burillo, Sebastian F. Hoenig   +19 more
doaj   +1 more source

Radio Emission from High-redshift Active Galactic Nuclei in the JADES and CEERS Surveys

The Astronomical Journal
Recent 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, Ammara Aftab, Daniel J. Whalen   +2 more
doaj   +1 more source

Gas Accretion from a Neighbouring Galaxy Fuels the Low-luminosity Active Galactic Nucleus in NGC 4278

The Astrophysical Journal
How 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, Nai-Ping Yu, Ming Zhu, Chuan-Peng Zhang, Xiao-Lan Liu, Mei Ai, Peng Jiang   +6 more
doaj   +1 more source

Strongly Magnetized Accretion with Low Angular Momentum Produces a Weak Jet

The Astrophysical Journal
We study the spherical accretion of magnetized plasma with low angular momentum onto a supermassive black hole, utilizing global general relativistic magnetohydrodynamic simulations.
Alisa Galishnikova, Alexander Philippov, Eliot Quataert, Koushik Chatterjee, Matthew Liska   +4 more
doaj   +1 more source

Probing The Central Engines Of Low-Luminosity Active Galactic Nuclei

, 2013
I give a brief review of the observational properties of low-luminosity AGNs (LLAGNs). I outline some unresolved issues in the study of LLAGNs, emphasizing the uncertainties in the role of the truncated thin accretion disk, the dusty obscuring torus and the origin of high-energy radiation (X-rays and gamma-rays).
openaire   +2 more sources

On the variable nature of low luminosity active galactic nuclei

, 2015
Tesis Univ. Granada.
openaire   +3 more sources

Ensemble Variability Properties of Active Galactic Nuclei in the SDSS DR17

The Astrophysical Journal
We 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, Vicki Sarajedini   +1 more
doaj   +1 more source

Continuum Reverberation in Active Galactic Nuclei Disks Only with Sufficient X-Ray Luminosity and Low Albedo

The Astrophysical Journal
Disk continuum reverberation mapping is one of the primary ways we learn about active galactic nuclei (AGN) accretion disks. Reverberation mapping assumes that time-varying X-rays incident on the accretion disk drive variability in UV–optical light ...
Amy Secunda, Yan-Fei Jiang, Jenny E. Greene   +2 more
doaj   +1 more source