Results 1 to 10 of about 3,055 (120)

Narrow Fe–Kα Reverberation Mapping Unveils the Deactivated Broad-line Region in a Changing-look Active Galactic Nucleus

open access: yesThe Astrophysical Journal, 2023
“Changing-look active galactic nuclei” (CLAGNs) are known to change their apparent types between types 1 and 2, usually accompanied by a drastic change in their luminosity on timescales of years.
Hirofumi Noda   +13 more
doaj   +1 more source

The Lively Accretion Disk in NGC 2992. III. Tentative Evidence of Rapid Ultrafast Outflow Variability

open access: yesThe Astrophysical Journal, 2023
We report on the 2019 XMM-Newton+NuSTAR monitoring campaign of the Seyfert galaxy NGC 2992, observed at one of its highest flux levels in the X-rays.
Alfredo Luminari   +10 more
doaj   +1 more source

Active Galactic Nuclei Search

open access: yesAtoms, 2017
We present the first results of medium-band photometric observations on the 1m Schmidt Telescope of Byurakan Astrophysical Observatory (Armenia). The object sample was created in the SA68 field.
Sergey Kotov, Sergey Dodonov
doaj   +1 more source

The Rapid Optical Variability of the Nearby Radio-loud AGN Pictor A: Introducing the Quaver Pipeline for AGN Science with TESS

open access: yesThe Astrophysical Journal, 2023
The sampling strategy of the Transiting Exoplanet Survey Satellite (TESS) makes TESS light curves extremely valuable for investigating the high cadence optical variability of active galactic nuclei (AGN).
Krista Lynne Smith, Lia F. Sartori
doaj   +1 more source

BASS. XXVIII. Near-infrared Data Release 2: High-ionization and Broad Lines in Active Galactic Nuclei

open access: yesThe Astrophysical Journal Supplement Series, 2022
We present the BAT AGN Spectroscopic Survey (BASS) Near-infrared Data Release 2 (DR2), a study of 168 nearby ( $\bar{z}=0.04$ , z < 0.6) active galactic nuclei (AGN) from the all-sky Swift Burst Array Telescope X-ray survey observed with the Very Large ...
Jakob S. den Brok   +22 more
doaj   +1 more source

Mid-infrared Properties of Narrow-line Seyfert 1 Galaxies Detected by LoTSS DR2

open access: yesThe Astrophysical Journal
Narrow-line Seyfert 1 galaxies (NLS1s), a subclass of active galactic nuclei (AGNs) in an early stage of the accretion process, are also found to host relativistic jets. However, currently known jetted NLS1s are rare. The majority of NLS1s are undetected
Xu-Liang Fan
doaj   +1 more source

Investigating Model Dependencies for Obscured Active Galactic Nuclei: A Case Study of NGC 3982

open access: yesThe Astrophysical Journal
X-ray spectroscopy of heavily obscured active galactic nuclei (AGN) offers a unique opportunity to study the circumnuclear environment of accreting supermassive black holes.
Kristína Kallová   +2 more
doaj   +1 more source

NuSTAR Observations of a Heavily X-Ray-obscured AGN in the Dwarf Galaxy J144013+024744

open access: yesThe Astrophysical Journal, 2023
We present a multiwavelength analysis of the dwarf Seyfert 2 galaxy J144013+024744, a candidate obscured active galactic nucleus (AGN) thought to be powered by an intermediate-mass black hole (IMBH, M _• ≈ 10 ^4 −10 ^6 M _⊙ ) of mass M _• ∼ 10 ^5.2 M _⊙ .
Shrey Ansh   +12 more
doaj   +1 more source

Multiwavelength and Environmental Properties of Variability Selected Low-luminosity Active Galactic Nuclei

open access: yesThe Astrophysical Journal
We present the multiwavelength and environmental properties of 37 variability-selected active galactic nuclei (AGNs), including 30 low-luminosity AGNs (LLAGNs), using a high cadence time-domain survey (All-Sky Automated Survey for SuperNovae) from a ...
Heechan Yuk, Xinyu Dai, Marko Mićić
doaj   +1 more source

A UV to X-Ray View of Soft Excess in Type 1 Active Galactic Nuclei. II. Broadband Correlations

open access: yesThe Astrophysical Journal
The physical origin of soft X-ray excess (SE) is a long-lasting question, with two prevailing theories—“warm corona” and “ionized reflection”—dominating the discussion.
Shi-Jiang Chen   +7 more
doaj   +1 more source

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