Results 1 to 10 of about 40,155 (147)

Changing-Look AGNs or Short-Lived Radio Sources? [PDF]

Frontiers in Astronomy and Space Sciences, 2017
The evolution of extragalactic radio sources has been a fundamental problem in the study of active galactic nuclei for many years. A standard evolutionary model has been created based on observations of a wide range of radio sources.
Aleksandra Wołowska, Magdalena Kunert-Bajraszewska, Kunal Mooley, Gregg Hallinan   +3 more
doaj   +6 more sources

Radio-loud and Radio-quiet Active Galactic Nuclei [PDF]

Astronomical Journal, 1999
We generated a sample of 409 AGNs for which both the radio luminosity at 5 GHz and the line luminosity in [OIII] 5007 have been measured. The radio luminosity spans a range of ten orders of magnitude, and the [OIII] line luminosity spans a range of eight
Chun Xu
exaly   +5 more sources

Unified Schemes for Radio-Loud Active Galactic Nuclei

Publications of the Astronomical Society of the Pacific, 1995
The appearance of active galactic nuclei (AGN) depends so strongly on orientation that our current classification schemes are dominated by random pointing directions instead of more interesting physical properties.
C Megan Urry, Paolo Padovani
exaly   +3 more sources

Multifrequency Studies of Active Galactic Nuclei in the Planck Satellite Era

Galaxies, 2016
The multi-epoch single-survey Planck satellite data have given a rare glimpse into how the radio spectra of active galactic nuclei (AGN) evolve in time.
Anne Lähteenmäki, the Planck Collaboration   +1 more
doaj   +3 more sources

X-ray properties of coronal emission in radio quiet active galactic nuclei

Frontiers in Astronomy and Space Sciences
Active galactic nuclei (AGN) are powerful sources of panchromatic radiation. All AGN emit in X-rays, contributing around 5%–10% of the AGN bolometric luminosity.
Sibasish Laha, Sibasish Laha, Sibasish Laha, Claudio Ricci, Claudio Ricci, John C. Mather, Ehud Behar, Luigi Gallo, Frederic Marin, Rostom Mbarek, Rostom Mbarek, Amelia Hankla   +11 more
doaj   +3 more sources

Search and Characterization of Remnant Radio Galaxies in the XMM-LSS Deep Field

The Astrophysical Journal, 2023
The remnant phase of a radio galaxy is characterized by the cessation of active galactic nuclei activity, resulting in the jets ceasing to feed plasma to the radio lobes.
Sushant Dutta, Veeresh Singh, C. H. Ishwara Chandra, Yogesh Wadadekar, Abhijit Kayal, Ian Heywood   +5 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

FRAMEx. IV. Mechanical Feedback from the Active Galactic Nucleus in NGC 3079

The Astrophysical Journal, 2023
Using the Very Long Baseline Array, we observed the active galactic nucleus (AGN) in NGC 3079 over a span of six months to test for variability in the two main parsec-scale radio components, A and B , which lie on either side of the AGN.
Luis C. Fernandez, Nathan J. Secrest, Megan C. Johnson, Travis C. Fischer   +3 more
doaj   +1 more source

Radio Sources in Low-Luminosity Active Galactic Nuclei.IV. Radio Luminosity Function, Importance of Jet Power, and Radio Properties of the Complete Palomar Sample [PDF]

, 2004
We present the completed results of a high resolution radio imaging survey of all (~200) low-luminosity active galactic nuclei (LLAGNs) and AGNs in the Palomar Spectroscopic Sample.
A. S. Wilson, Alonso-Herrero, Anderson, Antonucci, Barth, Barth, Beasley, Begelman, Bietenholz, Braatz, Carral, Celotti, Chatterjee, Colina, Condon, Condon, Condon, Cotton, Cotton, Crane, Dhawan, Di Matteo, Dopita, Emsellem, Fabbiano, Falcke, Falcke, Falcke, Fender, Fender, Ferrarese, Filho, Filho, Filippenko, Filippenko, Fomalont, Fosbury, Franceschini, Gebhardt, Gebhardt, Giovannini, Giovannini, H. Falcke, Heckman, Heckman, Heckman, Herrnstein, Ho, Ho, Ho, Ho, Ho, Ho, Ho, Ho, Hummel, Hummel, Hummel, Jones, Jones, Jones, Jones, Junor, Karachentsev, Kellermann, Koski, Krajnovic, Krichbaum, Kukula, Kukula, Laurent-Muehleisen, Lonsdale, Lonsdale, Lovelace, Maoz, Maoz, Marconi, Merloni, Merritt, Meurs, Middelberg, Mundell, Mundell, N. M. Nagar, Nagar, Nagar, Nagar, Nagar, Nagar, Napier, Napier, Narayan, Neff, Osterbrock, Owen, Pellegrini, Rawlings, Rees, Richstone, Sadler, Sadler, Sandage, Sanghera, Sargent, Schilizzi, Shields, Slee, Smith, Soltan, Stanger, Stoughton, Terashima, Terashima, Terlevich, Tremaine, Trotter, Ulvestad, Ulvestad, Ulvestad, Ulvestad, Ulvestad, van den Bergh, Venturi, Verdoes Kleijn, Vila, Walker, White, Woo, Wrobel, Wrobel, Wrobel, Wrobel, Xu, Zensus, Zirbel   +134 more
core   +17 more sources

Radio observations of active galactic nuclei with mm-VLBI [PDF]

, 2017
Over the past few decades, our knowledge of jets produced by active galactic nuclei (AGN) has greatly progressed thanks to the development of very-long-baseline interferometry (VLBI).
Boccardi, B., Krichbaum, T. P., Ros, E., Zensus, J. A.   +3 more
core   +2 more sources