Results 1 to 10 of about 78,490 (277)

Elusive Active Galactic Nuclei [PDF]

Monthly Notices of the Royal Astronomical Society, 2003
A fraction of active galactic nuclei do not show the classical Seyfert-type signatures in their optical spectra, i.e. they are optically "elusive". X-ray observations are an optimal tool to identify this class of objects.
A. Comastri, A. Krabbe, A. Marconi, Comastri A., E. Colbert, Franceschini A., G. Matt, Garcia-Barreto J. A., Goncalves A. C., Guainazzi M., M. Salvati, Maiolino R., Marconi A., Marconi A., Moorwood A. F. M., N. M. Nagar, R. Gilli, R. Maiolino, Risaliti G., S. Bianchi, Spoon H. W. W., T. Boker, Veron M. P., Veron-Cetty M.-P., Vignati P.   +24 more
core   +11 more sources

Obscured Active Galactic Nuclei [PDF]

AIP Conference Proceedings, 2000
The properties of the absorption in type 2, narrow line AGNs are reviewed by focusing on the X-ray indicators. I discuss the properties of the cold absorbing medium (the putative torus) and of the reprocessed components, as well as their implications for
Maiolino, R.
core   +7 more sources

Active Galactic Nuclei Search [PDF]

Atoms, 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   +2 more sources

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

The 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, Taisei Mineta, Takeo Minezaki, Hiroaki Sameshima, Mitsuru Kokubo, Taiki Kawamuro, Satoshi Yamada, Takashi Horiuchi, Hironori Matsumoto, Makoto Watanabe, Kumiko Morihana, Yoichi Itoh, Koji S. Kawabata, Yasushi Fukazawa   +13 more
doaj   +1 more source

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

The 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, Andrea Marinucci, Stefano Bianchi, Barbara de Marco, Chiara Feruglio, Giorgio Matt, Riccardo Middei, Emanuele Nardini, Enrico Piconcelli, Simonetta Puccetti, Francesco Tombesi   +10 more
doaj   +1 more source

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

The 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, Michael J. Koss, Benny Trakhtenbrot, Daniel Stern, Sebastiano Cantalupo, Isabella Lamperti, Federica Ricci, Claudio Ricci, Kyuseok Oh, Franz E. Bauer, Rogerio Riffel, Alberto Rodríguez-Ardila, Rudolf Bär, Fiona Harrison, Kohei Ichikawa, Julian E. Mejía-Restrepo, Richard Mushotzky, Meredith C. Powell, Rozenn Boissay-Malaquin, Marko Stalevski, Ezequiel Treister, C. Megan Urry, Sylvain Veilleux   +22 more
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

The 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

Investigation of Stellar Kinematics and Ionized Gas Outflows in Local (U)LIRGs

The Astrophysical Journal, 2023
We explore the properties of stellar kinematics and ionized gas in a sample of 1106 local (U)LIRGs from the AKARI telescope. We combine data from Wide-field Infrared Survey Explorer and Sloan Digital Sky Survey Data Release 13 to fit the spectral energy ...
Ashraf Ayubinia, Yongquan Xue, Huynh Anh Nguyen Le, Fan Zou, Shu Wang, Zhicheng He, Ece Kilerci   +6 more
doaj   +1 more source

Active galactic nuclei at z ~ 1.5: III. Accretion discs and black hole spin [PDF]

, 2016
This is the third paper in a series describing the spectroscopic properties of a sample of 39 AGN at $z \sim 1.5$, selected to cover a large range in black hole mass ($M_{BH}$) and Eddington ratio ($L/L_{Edd}$). In this paper, we continue the analysis of
Capellupo, Daniel M., Lira, Paulina, Mejía-Restrepo, Julián, Netzer, Hagai, Trakhtenbrot, Benny   +4 more
core   +2 more sources

Megamaser Disks in Active Galactic Nuclei [PDF]

, 1998
Recent spectroscopic and VLBI-imaging observations of bright extragalactic water maser sources have revealed that the megamaser emission often originates in thin circumnuclear disks near the centers of active galactic nuclei (AGNs).
Abraham Z., Antonucci R., Arav N., Arieh Konigl, Blandford R. D., Brown P. D., Fiebig D., Genzel R., Greenhill L. J., Greenhill L. J., Hagiwara Y., Hawarden T. G., Herrnstein J. R., John F. Kartje, Matveenko L. I., Moshe Elitzur, Nakai N., Pringle J. E., Pringle J. E., Pringle J. E., Schandl S., Shakura N. I.   +21 more
core   +4 more sources