Results 41 to 50 of about 39,820 (206)

MOMO. VI. Multifrequency Radio Variability of the Blazar OJ 287 from 2015 to 2022, Absence of Predicted 2021 Precursor-flare Activity, and a New Binary Interpretation of the 2016/2017 Outburst

The Astrophysical Journal, 2023
Based on our dedicated Swift monitoring program, MOMO, OJ 287 is one of the best-monitored blazars in the X-ray–UV–optical regime. Here, we report results from our accompanying, dense, multifrequency (1.4–44 GHz) radio monitoring of OJ 287 between 2015 ...
S. Komossa, A. Kraus, D. Grupe, A. G. Gonzalez, M. A. Gurwell, L. C. Gallo, F. K. Liu, I. Myserlis, T. P. Krichbaum, S. Laine, U. Bach, J. L. Gómez, M. L. Parker, S. Yao, M. Berton   +14 more
doaj   +1 more source

Radio and X-ray Observations of the Restarted Radio Galaxy in the Galaxy Cluster CL 0838+1948

Galaxies, 2021
We present VLA Low-band Ionosphere and Transient Experiment (VLITE) 338 MHz observations of the galaxy cluster CL 0838+1948. We combine the VLITE data with Giant Metrewave Radio Telescope 610 MHz observations and survey data.
Simona Giacintucci, Tracy Clarke, Namir E. Kassim, Wendy Peters, Emil Polisensky   +4 more
doaj   +1 more source

Radio Loudness of Active Galactic Nuclei: Observational Facts and Theoretical Implications [PDF]

The Astrophysical Journal, 2007
We investigate how the total radio luminosity of AGN-powered radio sources depends on their accretion luminosity and the central black hole mass. Our studies cover about seven orders of magnitude in accretion luminosity and the full range of AGN black hole masses. We find that AGNs form two distinct and well separated sequences on the radio-loudness --
Sikora, Marek, Stawarz, Łukasz, Lasota, Jean-Pierre   +2 more
openaire   +3 more sources

Testing the Linear Relationship between Black Hole Mass and Variability Timescale in Low-luminosity AGNs at Submillimeter Wavelengths

The Astrophysical Journal, 2023
The variability of submillimeter emission provides a useful tool to probe the accretion physics in low-luminosity active galactic nuclei. We accumulate four years of observations using the Submillimeter Array for Centaurus A, NGC 4374, NGC 4278, and NGC ...
Bo-Yan Chen, Geoffrey C. Bower, Jason Dexter, Sera Markoff, Anthony Ridenour, Mark A. Gurwell, Ramprasad Rao, Sofia H. J. Wallström   +7 more
doaj   +1 more source

The Correlation between X-ray spectral slope and FeKalpha line energy in radio-quiet active galactic nuclei

, 2002
A significant correlation between FeKalpha line energy and X-ray spectral slope has been discovered among radio-quiet active galactic nuclei. The ionization stage of the bulk of the FeKalpha emitting material is not the same in all active galactic nuclei
Arnaud K. A., Boller T., Brandt W. N., Fabian A. C., George I. M., Grupe D., Guainazzi M., Guilbert P. W., Gulab Chand Dewangan, Koenig M., Mineo T., Pounds K. A., Reynolds C. S., Winkler H., Wisotzki L.   +14 more
core   +1 more source

RAiSERed: radio continuum redshifts for lobed active galactic nuclei [PDF]

Monthly Notices of the Royal Astronomical Society, 2020
ABSTRACT Next-generation radio surveys are expected to detect tens of millions of active galactic nuclei (AGNs) with a median redshift of $z$ ≥ 1. Beyond targeted surveys, the vast majority of these objects will not have spectroscopic redshifts, while photometric redshifts for high-redshift AGNs are of limited quality, and even then ...
Ross J Turner, Guillaume Drouart, Nick Seymour, Stanislav S Shabala   +3 more
openaire   +1 more source

Cosmic Evolution of Nearby Radio Active Galactic Nuclei

Journal of Physics: Conference Series, 2019
Abstract The exact formation mechanism of massive galaxy in the universe still become an open question in modern astrophysics. Radio emission from active galactic nucleus (AGN) is known to be suppressing stellar growth in the most massive galaxies, thus becoming significant ingredient in modeling galaxy formation process.
Taufik Andika, I., Ikbal Arifyanto, M., Istiqomah, A., Amalina, S., Aprilia, Hakim, M.   +5 more
openaire   +2 more sources

HerMES: SPIRE emission from radio-selected active galactic nuclei★ [PDF]

Monthly Notices of the Royal Astronomical Society, 2011
We examine the rest-frame far-infrared emission from powerful radio sources with 1.4-GHz luminosity densities of25 ≤ log(L1.4/WHz-1) ≤ 26.5in the extragalacticSpitzerFirst Look Survey field. We combineHerschel/SPIRE flux densities withSpitzer/Infrared Array Camera and Multiband Imaging Photometer forSpitzerinfrared data to obtain total (m) infrared ...
N. Seymour, M. Symeonidis, M. J. Page, A. Amblard, V. Arumugam, H. Aussel, A. Blain, J. Bock, A. Boselli, V. Buat, N. Castro-Rodríguez, A. Cava, P. Chanial, D. L. Clements, A. Conley, L. Conversi, A. Cooray, C. D. Dowell, E. Dwek, S. Eales, D. Elbaz, A. Franceschini, J. Glenn, E. A. González Solares, M. Griffin, E. Hatziminaoglou, E. Ibar, K. Isaak, R. J. Ivison, G. Lagache, L. Levenson, N. Lu, S. Madden, B. Maffei, G. Mainetti, L. Marchetti, H. T. Nguyen, B. O’Halloran, S. J. Oliver, A. Omont, P. Panuzzo, A. Papageorgiou, C. P. Pearson, I. Pérez-Fournon, M. Pohlen, J. I. Rawlings, D. Rizzo, I. G. Roseboom, M. Rowan-Robinson, B. Schulz, Douglas Scott, D. L. Shupe, A. J. Smith, J. A. Stevens, M. Trichas, K. E. Tugwell, M. Vaccari, I. Valtchanov, L. Vigroux, L. Wang, G. Wright, C. K. Xu, M. Zemcov   +62 more
openaire   +4 more sources

A Radio Census of Binary Supermassive Black Holes

, 2010
Using archival VLBI data for 3114 radio-luminous active galactic nuclei, we searched for binary supermassive black holes using a radio spectral index mapping technique which targets spatially resolved, double radio-emitting nuclei.
Beasley, Begelman, Boroson, Britzen, Colpi, Comerford, De Lucia, De Propris, Decarli, Detweiler, Dunlop, Enoki, Ferrarese, Fomalont, Frank, Giovannini, Gualandris, Haring, Jaffe, Jenet, Komossa, Komossa, Kovalev, Lacey, Lister, Lovell, Mason, Mauch, McLure, Merritt, Merritt, Myers, Owsianik, Padovani, Peterson, Petrov, Petrov, Petrov, Pollack, Rajagopal, Rodriguez, S. Burke-Spolaor, Saripalli, Sault, Sesana, Sesana, Slee, Springel, Sudou, Valtonen, Volonteri, Walker, Wang, Wen, Wilkinson, Wyithe, Yu   +56 more
core   +1 more source

The TANAMI Program [PDF]

, 2009
TANAMI (Tracking Active Galactic Nuclei with Austral Milliarcsecond Interferometry) is a monitoring program to study the parsec-scale structures and dynamics of relativistic jets in active galactic nuclei (AGN) of the Southern Hemisphere with the Long ...
Boeck, M., Booth, R., Dutka, M. S., Edwardsk, P., Fey, A. L., Fuhrmann, L., Hase, H., Horiuchi, S., Jauncey, D. L., Johnston, K. J., Kadler, Matthias, Katz, U., Lister, M., Lovell, J. E. J., Mueller, Cornelia, Ojha, Roopesh, Ploetz, C., Quick, J. F. H., Ros, E., Taylor, G. B., Thompson, D. J., Tingay, S. J., Tosti, G., Tzioumisk, A. K., Wilms, J., Zensus, J. A.   +25 more
core   +2 more sources