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Using new 610 MHz and 235 MHz observations from the Giant Metrewave Radio Telescope (GMRT) in combination with archival GMRT and Very Large Array (VLA) survey data we present the radio properties of the dominant early-type galaxies in the…

In this study we investigate 89 radio galaxies that are spectroscopically-confirmed to be members of five large scale structures in the redshift range of $0.65 \le z \le 0.96$. Based on a two-stage classification scheme, the radio galaxies…

We present a spectroscopic catalogue of 40 luminous starburst galaxies at z=0.7--1.7 (median z=1.3). 19 of these are submillimetre galaxies (SMGs) and 21 are submillimetre-faint radio galaxies (SFRGs). This sample helps to fill in the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Manda Banerji , Scott C. Chapman , Ian Smail , S. Alaghband-Zadeh , A. M. Swinbank , J. S. Dunlop , R. J. Ivison , A. W. Blain

Giant radio galaxies (GRGs), a minority among the extended-jetted population, form in a wide range of jet and environmental configurations, complicating the identification of the growth factors that facilitate their attainment of megaparsec…

Astrophysics of Galaxies · Physics 2024-11-19 Gourab Giri , Joydeep Bagchi , Kshitij Thorat , Roger P. Deane , Jacinta Delhaize , D. J. Saikia

Basing our analysis on ROGUE I, a catalog of over 32,000 radio sources associated with optical galaxies, we provide two diagnostics to select the galaxies where the radio emission is due to an active galactic nucleus (AGN). Each of these…

Giant Radio Galaxies (GRGs) are Active Galactic Nuclei (AGN) with radio emission that extends over projected sizes $>0.7\,$Mpc. The large angular sizes associated with GRGs complicate their identification in radio survey images using…

Astrophysics of Galaxies · Physics 2023-11-16 Soren Ramdhanie , Yjan A. Gordon , Heinz Andernach , Eric J. Hooper , Brianna Sampson

We report on the use of the NRAO VLA Sky Survey (NVSS) to identify radio galaxie s in eighteen nearby Abell clusters. The listings extend from the cores of the clusters out to radii of 3 Mpc, which corresponds to 1.5 Abell radii and…

Astrophysics · Physics 2009-11-06 Neal A. Miller , Frazer N. Owen

Radio galaxies dominate the radio sky and are essential to the galaxy evolution puzzle. High-resolution studies of statistical samples of radio galaxies are expected to shed light on the triggering mechanisms of the AGN, alternating between…

Astrophysics of Galaxies · Physics 2023-11-22 N. Jurlin , R. Morganti , F. Sweijen , L. K. Morabito , M. Brienza , P. Barthel , G. K. Miley

It has been known for nearly three decades that high redshift radio galaxies exhibit steep radio spectra, and hence ultra-steep spectrum radio sources provide candidates for high-redshift radio galaxies. Nearly all radio galaxies with z > 3…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 C. H. Ishwara-Chandra , S. K. Sirothia , Y. Wadadekar , S. Pal , R. Windhorst

NGC 4527 is a nearby edge-on spiral galaxy with both starburst and AGN features, hosting a LINER nucleus. We present a radio study of the large-scale structure and nuclear region of this galaxy, based on new uGMRT observations at 700 and…

Astrophysics of Galaxies · Physics 2025-09-03 C. A. Galante , G. E. Romero , J. Saponara , P. Benaglia

Less than $200$ radio-loud active galactic nuclei (AGN) are known above redshift $4$. Around $40$ of them have been observed at milliarcsecond (mas) scale resolution with very long baseline interferometry (VLBI) technique. Some of them are…

We present the first systematic study of the radio continuum size evolution of star-forming galaxies (SFGs) over the redshift range $0.35<z<2.25$. We use the VLA COSMOS 3GHz map (noise $\rm rms=2.3\,\mu Jy \,beam^{-1}$, $\theta_{\rm…

Dust is commonly present in weakly radio emitting star-forming galaxies and this dust may obscure the signatures of accreting black holes in these objects. We aim to uncover weak active galactic nuclei, AGN, in the faint radio source…

Cosmology and Nongalactic Astrophysics · Physics 2013-01-08 S. Chi , P. D. Barthel , M. A. Garrett

We have carried out an analysis of the radio and optical properties of a statistical sample of 45 Seyfert galaxies from the Palomar spectroscopic survey of nearby galaxies. We find that the space density of bright galaxies (-22 mag <=…

Astrophysics · Physics 2009-11-06 James S. Ulvestad , Luis C. Ho

We present the results from 685 MHz observations with the upgraded Giant Metrewave Radio Telescope (uGMRT) of 22 quasars belonging to the Palomar-Green (PG) quasar sample. Only four sources reveal extended radio structures on $\sim$10-30…

Astrophysics of Galaxies · Physics 2020-12-22 Silpa S. , P. Kharb , L. C. Ho , C. H. Ishwara-Chandra , M. E. Jarvis , C. Harrison

We have started a search for High Redshift Radio Galaxies (HZRGs) in an area covering 7 sr by selecting a sample of Ultra Steep Spectrum (USS) sources with a low flux density cut-off S(1400 MHz) > 10 mJy and a steep spectral index cut-off…

Astrophysics · Physics 2016-01-27 Carlos De Breuck , Wil van Breugel , Huub Rottgering , George Miley

Context: Diffuse radio emission, in the form of radio halos and relics, traces regions in clusters with shocks or turbulence, probably produced by cluster mergers. Some models of diffuse radio emission in clusters indicate that virtually…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 R. J. van Weeren , H. J. A. Rottgering , M. Bruggen , A. Cohen

We present radio very long baseline interferometry (VLBI) and X-ray studies of the starburst galaxy NGC 3628. The VLBI observation at 1.5 GHz reveals seven compact (0.7$-$7 parsec) radio sources in the central $\sim$250 parsec region of NGC…

Astrophysics of Galaxies · Physics 2023-07-26 Xiaolong Yang , Ziwei Ou

The GLOSTAR survey will study the star formation in the Galactic plane between $-2^{\circ}< \textit{l}< 85^{\circ}$ and $|b| < 1^{\circ}$ with unprecedented sensitivity in both, flux density ($\sim$ 40 $\mu Jy$ beam$^{-1}$) and range of…

Many massive early-type galaxies host central radio sources and hot X-ray atmospheres indicating the presence of radio-mechanical active galactic nucleus (AGN) feedback. The duty cycle and detailed physics of the radio-mode AGN feedback is…