English
Related papers

Related papers: Studies on slow radio transients

200 papers

Recent sensitive wide-field radio surveys, such as the LOFAR Two Meter Sky Survey (LoTSS), the LOFAR LBA Sky Survey (LoLSS), and the Very Large Array Sky Survey (VLASS), enable the selection of statistically large samples of peaked-spectrum…

Astrophysics of Galaxies · Physics 2024-09-25 F. J. Ballieux , J. R. Callingham , H. J. A. Röttgering , M. M. Slob

The term 'active galactic nuclei' (AGN) subtends a huge variety of objects, classified on their properties at different wavelengths. Peaked sources (PS) represent a class of AGN at the first stage of evolution, characterised by a peaked…

Astrophysics of Galaxies · Physics 2024-09-11 A. Vietri , M. Berton , E. Järvelä , M. Kunert-Bajraszewska , S. Ciroi , I. Varglund , B. Dalla Barba , E. Sani , L. Crepaldi

In this paper we give a brief review of the astrophysics of active galactic nuclei (AGN). After a general introduction motivating the study of AGNs, we discuss our present understanding of the inner workings of the central engines, most…

Cosmology and Nongalactic Astrophysics · Physics 2013-01-18 Henric Krawczynski , Ezequiel Treister

A sample of radio-loud active galactic nuclei (AGN) at 2cm is studied to test the isotropic distribution of radio sources in the sky and their uniform distribution in space. The sample is complete flux-density limits of 1.5Jy for positive…

Astrophysics · Physics 2017-08-23 T. G. Arshakian , E. Ros , J. A. Zensus , M. L. Lister

We investigate the relationship between radio power and properties related to active galactic nuclei (AGNs). Radio power at 1.4 or 5 GHz, which has been used in many studies, can be affected by synchrotron self-absorption and free-free…

Astrophysics of Galaxies · Physics 2015-06-17 Songyoun Park , Bong Won Sohn , Sukyoung K. Yi

We present the results of spectroscopic observations of host galaxies of eleven candidate giant radio galaxies (GRGs), powered by active galactic nuclei (AGNs), conducted with the 2-m Himalayan Chandra Telescope (HCT). The primary aim of…

Astrophysics of Galaxies · Physics 2025-02-11 Sagar Sethi , Pratik Dabhade , K. G. Biju , C. S. Stalin , Marek Jamrozy

We explore the connection between different classes of active galactic nuclei (AGNs) and the evolution of their host galaxies, by deriving host galaxy properties, clustering, and Eddington ratios of AGNs selected in the radio, X-ray, and…

Astrophysics of Galaxies · Physics 2009-03-24 Ryan C. Hickox , the Bootes survey collaboration

(Abridged) We present the results from new 15 ks Chandra-ACIS and 4.9 GHz Very Large Array observations of 13 galaxies hosting low luminosity AGN. This completes the multiwavelength study of a sample of 51 nearby early-type galaxies…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Preeti Kharb , A. Capetti , D. J. Axon , M. Chiaberge , P. Grandi , A. Robinson , G. Giovannini , B. Balmaverde , D. Macchetto , R. Montez

Radio observations allow us to identify a wide range of active galactic nuclei (AGN), which are galaxies that have gas accreting onto the supermassive black-hole at the centre. By observing these sources at multiple radio frequencies, a…

Astrophysics of Galaxies · Physics 2023-07-19 Sarah V. White

We report on the discovery of one of the most extreme cases of high-frequency radio variability ever measured in active galactic nuclei (AGN), observed on timescales of days and exhibiting variability amplitudes of three to four orders of…

We propose that Gigahertz Peak Spectrum (GPS) and Compact Steep Spectrum (CSS) radio sources are the signposts of relativistic jet feedback in evolving galaxies. Our simulations of relativistic jets interacting with a warm, inhomogeneous…

Low-luminosity AGNs are perceived to be radio loud and devoid of a ``big blue bump'', indicating a transition from a radiatively efficient, geometrically thin, accretion disc in high-luminosity AGNs, to a geometrically thick, radiatively…

Astrophysics · Physics 2008-11-26 Dan Maoz

Properties of galaxies depend on their large-scale environment. As the influence of active galactic nuclei (AGN) in galaxy evolution is becoming more evident, their large scale environments may help us understand the evolutionary processes…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 H. Lietzen , P. Heinämäki , P. Nurmi , L. J. Liivamägi , E. Saar , E. Tago , L. O. Takalo , M. Einasto

The nature of the so-called ``changing-look'' (CL) active galactic nucleus (AGN), which is characterized by spectral-type transitions within $\sim10$~yr, remains an open question. As the first in our series of studies, we here attempt to…

Cosmology and Nongalactic Astrophysics · Physics 2023-09-22 J. Wang , W. K. Zheng , T. G. Brink , D. W. Xu , A. V. Filippenko , C. Gao , C. H. Xie , J. Y. Wei

We investigate the origin of the parsec-scale radio emission from the changing-look active galactic nucleus (AGN) of Mrk 590, and examine whether the radio power has faded concurrently with the dramatic decrease in accretion rates observed…

Astrophysics of Galaxies · Physics 2016-06-30 J. Y. Koay , M. Vestergaard , H. E. Bignall , C. Reynolds , B. M. Peterson

While supermassive black holes are ubiquitous features of galactic nuclei, only a small minority are observed during episodes of luminous accretion. The physical mechanism(s) driving the onset of fueling and ignition in these active…

Here we discuss evolution and broad-band emission of compact (< kpc) lobes in young radio sources. We propose a simple dynamical description for these objects, consisting of a relativistic jet propagating into a uniform gaseous medium in…

Astrophysics · Physics 2009-11-13 L. Stawarz , L. Ostorero , M. C. Begelman , R. Moderski , J. Kataoka , S. Wagner

We present a multifrequency radio continuum study of seven giant low surface brightness (GLSB) galaxies using the Giant Metrewave Radio Telescope (GMRT). GLSB galaxies are optically faint, dark-matter dominated systems that are poorly…

Astrophysics of Galaxies · Physics 2015-06-23 Alka Mishra , N. G. Kantharia , M. Das , D. C. Srivastava , S. N. Vogel

We explore radio and spectroscopic properties of a sample of 14 miniature radio galaxies, i.e. early-type core galaxies hosting radio-loud AGN of extremely low radio power, 10^(27-29) erg s^(-1) Hz^(-1) at 1.4 GHz. Miniature radio galaxies…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 Ranieri D. Baldi , Alessandro Capetti

We analyze the optical spectra of massive (log M*/Msun > 11.4) radio-loud galaxies at z~0.2 and z~0.6. By comparing stellar population parameters of these radio-loud samples with radio-quiet control samples, we investigate how the presence…