Results 51 to 60 of about 25,311 (211)

Radio Emission from Active Galactic Nuclei [PDF]

Symposium - International Astronomical Union, 1987
Active Galactic Nuclei and quasars are characterized at radio wavelengths by a high surface brightness, a flat spectrum, variations in intensity on time scales of a few days to a few years, and by large internal motions which probably reflect Doppler beaming from a synchrotron source which is moving with relativistic velocity away from the central ...
openaire   +1 more source

Optical-radio positional offsets for active galactic nuclei [PDF]

Astronomy & Astrophysics, 2013
Context. It will soon become possible to directly link the most accurate radio reference frame with the Gaia optical reference frame using many common extragalactic objects. It is important to know the level of coincidence between the radio and optical positions of compact active galactic nuclei (AGN). Aims.
Orosz, Gábor, Frey, Sándor
openaire   +3 more sources

Millimeter-Wave Monitoring of Active Galactic Nuclei with the Africa Millimetre Telescope

Galaxies, 2019
Active galactic nuclei are the dominant sources of gamma rays outside our galaxy and are also candidates for the source of ultra-high energy cosmic rays.
Michael Backes, Markus Böttcher, Heino Falcke   +2 more
doaj   +1 more source

Active galactic nuclei as seen by the Spitzer Space Telescope [PDF]

, 2020
The Spitzer Space Telescope revolutionized studies of active galactic nuclei (AGNs). Its combined sensitivity and mapping speed at mid-infrared wavelengths revealed a substantial population of highly obscured AGNs.
M. Lacy, A. Sajina
semanticscholar   +1 more source

VLBI observations of nearby radio loud active galactic nuclei

Journal of Physics: Conference Series, 2008
6 pages, 7 figures, Proceedings for "The Universe under the Microscope" (AHAR 2008), April 2008, to be published in Journal of Physics: Conference Series by Institute of Physics Publishing; R. Schoedel, A. Eckart, S. Pfalzner, and E.
GIOVANNINI, GABRIELE, LIUZZO, ELISABETTA TEODORINA, Giroletti M., Taylor G. B.   +3 more
openaire   +3 more sources

Milky Way scattering properties and intrinsic sizes of active galactic nuclei cores probed by very long baseline interferometry surveys of compact extragalactic radio sources [PDF]

, 2015
We have measured the angular sizes of radio cores of active galactic nuclei (AGN) and analyzed their sky distributions and frequency dependencies to study synchrotron opacity in AGN jets and the strength of angular broadening in the interstellar medium ...
A. Pushkarev, Y. Kovalev
semanticscholar   +1 more source

The Fourth Catalog of Active Galactic Nuclei Detected by the Fermi Large Area Telescope [PDF]

Astrophysical Journal, 2019
The fourth catalog of active galactic nuclei (AGNs) detected by the Fermi Gamma-ray Space Telescope Large Area Telescope (4LAC) between 2008 August 4 and 2016 August 2 contains objects located at high Galactic latitudes ( ).
M. Ajello, R. Angioni, M. Axelsson, J. Ballet, G. Barbiellini, D. Bastieri, J. Becerra González, R. Bellazzini, E. Bissaldi, E. Bloom, R. Bonino, E. Bottacini, P. Bruel, S. Buson, F. Cafardo, R. Cameron, E. Cavazzuti, S. Chen, C. Cheung, S. Ciprini, D. Costantin, S. Cutini, F. D’Ammando, P. De la Torre Luque, R. de Menezes, F. de Palma, A. Desai, w sarada, L. Di Venere, A. Domínguez, F. Dirirsa, E. Ferrara, J. Finke, A. Franckowiak, Y. Fukazawa, S. Funk, P. Fusco, F. Gargano, S. Garrappa, D. Gasparrini, N. Giglietto, F. Giordano, M. Giroletti, D. Green, I. Grenier, S. Guiriec, S. Harita, E. Hays, D. Horan, R. Itoh, G. Jóhannesson, M. Kovac’evic’, F. Krauß, M. Kreter, M. Kuss, S. Larsson, C. Leto, J. Li, I. Liodakis, F. Longo, F. Loparco, B. Lott, M. Lovellette, P. Lubrano, G. Madejski, S. Maldera, A. Manfreda, G. Martí-Devesa, F. Massaro, M. Mazziotta, I. Mereu, M. Meyer, G. Migliori, N. Mirabal, T. Mizuno, M. Monzani, A. Morselli, I. Moskalenko, M. Negro, R. Nemmen, É. Nuss, L. Ojha, R. Ojha, N. Omodei, M. Orienti, E. Orlando, J. Ormes, V. Paliya, Z. Pei, H. Peña-Herazo, M. Persic, M. Pesce-Rollins, L. Petrov, F. Piron, Hoifung Poon, G. Principe, S. Rainò, R. Rando, Babita Rani, M. Razzano, S. Razzaque, A. Reimer, O. Reimer, F. Schinzel, D. Serini, C. Sgro’, E. Siskind, G. Spandre, P. Spinelli, D. Suson, Y. Tachibana, D. Thompson, D. Torres, E. Torresi, E. Troja, J. Valverde, P. van Zyl, M. Yassine   +117 more
semanticscholar   +1 more source

Gamma-Ray Bursts and Radio Loud Active Galactic Nuclei [PDF]

AIP Conference Proceedings, 2004
8 pages, 2 figures invited talk at the Symposium: "Plasmas in the Laboratory and in the Universe: new insights and new challenges", September 16-19, 2003, Como ...
openaire   +2 more sources

Phase‐Dependent Oxygen Defect Energetics in Epitaxial NbN/AlN/NbN Films

Advanced Science, EarlyView.
Phase dependent oxygen defect energetics in epitaxial δ‐NbN/AlN/δ‐NbN and β‐Nb2N/AlN/β‐Nb2N trilayers. Atomic‐scale analysis and first‐principles calculations reveal distinct oxygen incorporation pathways across NbN polymorphs. Layer resolved defect formation energies show that O is energetically more favorable within δ‐NbN electrodes, whereas in β ...
Prachi Garg, Kedarsh Kaushik, Danqing Wang, Naomi Pieczulewski, Anand Ithepalli, John Wright, Debdeep Jena, David A. Muller, Hong X. Tang, Cyrus Dreyer, Baishakhi Mazumder   +10 more
wiley   +1 more source

VLA FRAMEx. III. Circumnuclear Radio Emission Mechanisms in Hard X-Ray Selected Active Galactic Nuclei

The Astrophysical Journal
We present Stokes I continuum analysis for a volume-limited sample (
Andrew J. Sargent, Alexander J. van der Horst, Megan C. Johnson, Nathan J. Secrest, Travis C. Fischer, Onic I. Shuvo, Macon A. Magno, Luis C. Fernandez   +7 more
doaj   +1 more source