Results 41 to 50 of about 1,904 (106)

The QPO in RE J1034+396 Originates in the Hot Corona

The Astrophysical Journal
RE J1034+396 is one of the few active galactic nuclei (AGNs) with a significant quasiperiodic oscillation (QPO). The QPO has been observed in over 1 Ms of XMM-Newton observations spanning over a decade. We investigate the power spectral density function (
Chloe S. Taylor, Dan R. Wilkins, Steven W. Allen   +2 more
doaj   +1 more source

Reverberation Mapping Data of NGC 5548 Imply a Multicomponent Broad-line Region

The Astrophysical Journal
Line broadening and variability are observational hallmarks of active galactic nuclei (AGN) which allow us to measure supermassive black hole masses as well as constrain the geometry and kinematics of the emitting gas, with the most precise measurements ...
Kirk Long, Jason Dexter
doaj   +1 more source

Identifying the Secondary Jet in the RadioAstron Image of OJ 287

The Astrophysical Journal
The 136 yr long optical light curve of OJ 287 is explained by a binary black hole model where the secondary is in a 12 yr orbit around the primary. Impacts of the secondary on the accretion disk of the primary generate a series of optical flares that ...
Mauri J. Valtonen, Lankeswar Dey, Staszek Zola, Alok C. Gupta, Shubham Kishore, Achamveedu Gopakumar, Paul J. Wiita, Minfeng Gu, Kari Nilsson, Zhongli Zhang, Rene Hudec, Katsura Matsumoto, Marek Drozdz, Waldemar Ogloza, Andrei V. Berdyugin, Daniel E. Reichart, Markus Mugrauer, Tapio Pursimo, Stefano Ciprini, Tatsuya Nakaoka, Makoto Uemura, Ryo Imazawa, Michal Zejmo, Vladimir V. Kouprianov, James W. Davidson Jr., Alberto Sadun, Jan Štrobl, Martin Jelínek, Abhimanyu Susobhanan   +28 more
doaj   +1 more source

Flux States of Active Galactic Nuclei

Galaxies, 2019
Blazars are known to show variability on time scales from minutes to years covering a wide range of flux states. Studying the flux distribution of a source allows for various insights.
Daniela Dorner, Axel Arbet-Engels, Dominik Baack, Matteo Balbo, Adrian Biland, Michael Blank, Thomas Bretz, Kai Bruegge, Michael Bulinski, Jens Buss, Manuel Doerr, Dominik Elsaesser, Dorothee Hildebrand, Lena Linhoff, Karl Mannheim, Sebastian Achim Mueller, Dominik Neise, Andrii Neronov, Maximilian Noethe, Aleksander Paravac, Wolfgang Rhode, Bernd Schleicher, Florian Schulz, Kevin Sedlaczek, Amit Shukla, Vitalii Sliusar, Elan von Willert, Roland Walter, FACT Collaboration   +28 more
doaj   +1 more source

Probing the Dust Torus Radius–Luminosity Relation: A WISE View

The Astrophysical Journal
We present measurements of the dusty torus sizes of 51 active galactic nuclei (AGNs) with a redshift of z  
Ashutosh Tomar, Suvendu Rakshit, Amit Kumar Mandal, Shivangi Pandey   +3 more
doaj   +1 more source

PEARLS: Discovery of Point-source Features within Galaxies in the North Ecliptic Pole Time Domain Field

The Astrophysical Journal
The first public 0.9–4.4 μ m NIRCam images of the North Ecliptic Pole Time Domain Field uncovered galaxies displaying point-source features in their cores as seen in the longer-wavelength filters. We visually identified a sample of 66 galaxies (∼1 galaxy
Rafael Ortiz III, Rogier A. Windhorst, Seth H. Cohen, Steven P. Willner, Rolf A. Jansen, Timothy Carleton, Patrick S. Kamieneski, Michael J. Rutkowski, Brent M. Smith, Jake Summers, Cheng Cheng, Dan Coe, Christopher J. Conselice, Jose M. Diego, Simon P. Driver, Jordan C. J. D’Silva, Brenda L. Frye, Hansung B. Gim, Norman A. Grogin, Heidi B. Hammel, Nimish P. Hathi, Benne W. Holwerda, Minhee Hyun, Myungshin Im, William C. Keel, Anton M. Koekemoer, Juno Li, Madeline A. Marshall, Tyler J. McCabe, Noah J. McLeod, Stefanie N. Milam, Rosalia O’Brien, Nor Pirzkal, Aaron S. G. Robotham, Russell E. Ryan Jr., Christopher N. A. Willmer, Haojing Yan, Min S. Yun, Adi Zitrin   +38 more
doaj   +1 more source

Mid-infrared Variability in Nearby Galaxies from the MaNGA Sample

The Astrophysical Journal
We use mid-infrared variability in galaxies to search for active galactic nuclei (AGN) in the local universe. We use a sample of 10,220 galaxies from the Mapping Nearby Galaxies at Apache Point Observatory survey, part of the Sloan Digital Sky Survey ...
Aashay Pai, Michael R. Blanton, John Moustakas   +2 more
doaj   +1 more source

A Catalog of Broad Hα and Hβ Active Galactic Nuclei in MaNGA

The Astrophysical Journal
Broad H α and H β emission lines (FWHM > 1000 km s ^−1 ) are incredibly efficient tracers of the high-velocity clouds encircling active galactic nuclei (AGNs).
James Negus, Julia M. Comerford, Francisco Müller Sánchez   +2 more
doaj   +1 more source

VLA FRAMEx. II. Radio Spectra of Nearby Active Galactic Nuclei at Subarcsecond Resolution

The Astrophysical Journal
We present 4–12 GHz in-band spectral energy distributions with accompanying 6 GHz and 10 GHz imaging results for a volume-complete sample ( 0) spectral indices.
Andrew J. Sargent, Alexander J. van der Horst, Megan C. Johnson, Travis C. Fischer, Nathan J. Secrest, Phil J. Cigan, Onic I. Shuvo, Krista L. Smith   +7 more
doaj   +1 more source

Test for Echo: X-Ray Reflection Variability in the Seyfert-2 Active Galactic Nucleus NGC 4388

The Astrophysical Journal
We report on a study of the narrow Fe K α line and reflection spectrum in the well-known Seyfert-2 active galactic nucleus (AGN), NGC 4388. X-ray spectra summed from two extensive NICER monitoring campaigns, separated by years, show strong evidence of ...
Ben Gediman, Jon M. Miller, Abderahmen Zoghbi, Paul Draghis, Zaven Arzoumanian, W. N. Brandt, Keith Gendreau   +6 more
doaj   +1 more source