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Related papers: MIGHTEE: A first look at MIGHTEE quasars

200 papers

We present 6 cm Very Large Array observations of the Greene & Ho (2004) sample of 19 low-mass active galaxies with high accretion rates. This is one of the only studies of a uniform sample of narrow-line Seyfert 1 (NLS1) galaxies with such…

Astrophysics · Physics 2009-11-13 Jenny E. Greene , Luis C. Ho , James S. Ulvestad

We have quantified the galaxy environments around a sample of 0.5 < z < 0.8 radio-quiet quasars using the amplitude of the spatial galaxy--quasar correlation function, B_gq. The quasars exist in a wide variety of environments, some sources…

Astrophysics · Physics 2009-10-31 M. Wold , M. Lacy , P. B. Lilje , S. Serjeant

Quasars are generally divided into jetted radio-loud and non-jetted radio-quiet ones, but why only 10% quasars are radio loud has been puzzling for decades. Other than jet-induced-phenomena, black hole mass, or Eddington ratio, prominent…

Astrophysics of Galaxies · Physics 2024-06-21 Wen-Yong Kang , Jun-Xian Wang , Zhen-Yi Cai , Hao-Chen Wang , Wen-Ke Ren , Mai Liao , Feng Yuan , Andrzej Zdziarski , Xinwu Cao

We investigate the radio emitting structures of radio-quiet active galactic nuclei with an emphasis on radio-quiet quasars to study their connection to Seyfert galaxies. We present and analyse high-sensitivity VLA radio continuum images of…

Astrophysics · Physics 2009-11-11 Christian Leipski , Heino Falcke , Nicola Bennert , Susanne Huettemeister , ;

Using the most recent (1998) version of the VLA FIRST survey radio catalog, we have searched for radio emission from 1704 quasars taken from the most recent (1993) version of the Hewitt and Burbidge quasar catalog. These quasars lie in the…

Astrophysics · Physics 2009-10-31 Yogesh Wadadekar , Ajit Kembhavi

Recent works have suggested that selection criteria based on MIR colors can be used to reveal a population of dust-enshrouded, extremely luminous quasars at z>1. However the X-ray spectral properties of these intriguing sources still remain…

Cosmology and Nongalactic Astrophysics · Physics 2009-11-13 G. Lanzuisi , E. Piconcelli , F. Fiore , C. Feruglio , C. Vignali , M. Salvato , C. Gruppioni

We examine the distribution of radio emission from ~42,000 quasars from the Sloan Digital Sky Survey, as measured in the LOFAR Two-Metre Sky Survey (LoTSS). We present a model of the radio luminosity distribution of the quasars that assumes…

The energy released by active galactic nuclei (AGNs) is considered to have a profound impact on the cold gas properties of their host galaxies, potentially heating or removing the gas and further suppressing star formation. To understand…

Astrophysics of Galaxies · Physics 2026-01-27 Yuhan Wen , Ran Wang , Luis C. Ho , Jinyi Shangguan , Ezequiel Treister , Guodong Li , Franz E. Bauer

Radio-loud Active Galactic Nuclei at z~2-4 are typically located in dense environments and their host galaxies are among the most massive systems at those redshifts, providing key insights for galaxy evolution. Finding radio-loud quasars at…

We report the discovery of a radio loud quasar with a redshift of 4.30. This object, which is the first radio selected quasar with a redshift greater than four, was discovered during an observational investigation into the evolution of the…

We present a new sample of 35 quasars selected from the FIRST radio survey and the Deeprange I-band survey (Postman et al. 1998, 2002). A comparison with the FIRST Bright Quasar survey samples reveals that this I-band selected sample is…

We investigate the properties of the environment around 20 powerful radio galaxies and quasars at redshifts between 0.45 and 1. Using XMM-Newton and Chandra observations we probe the spatial distribution and the temperature of the cluster…

Astrophysics · Physics 2009-11-13 Elena Belsole , Diana M. Worrall , Martin J. Hardcastle , Judith H. Croston

In order to test the unified scheme for luminous radio galaxies and quasars we observed 10 galaxy/quasar pairs from the 3CR catalogue with ISOPHOT at infrared wavelengths between 5 and 180 micron. Each pair was selected such that both the…

Astrophysics · Physics 2009-11-06 K. Meisenheimer , M. Haas , S. A. H. Müller , R. Chini , U. Klaas , D. Lemke

In this study we investigate 179 radio-IR galaxies drawn from a sample of spectroscopically-confirmed galaxies that are detected in radio and mid-infrared (MIR) in the redshift range of $0.55 \leq z \leq 1.30$ in the Observations of…

We studied a sample of 274 radio and X-ray selected quasars (XQSOs) detected in the COSMOS and XXL-S radio surveys at 3 GHz and 2.1 GHz, respectively. This sample was identified by adopting a conservative threshold in X-ray luminosity, Lx…

Giant radio quasars (GRQs) are radio-loud active galactic nuclei (AGNs), propelling megaparsec-scale jets. In order to understand GRQs and their properties, we have compiled all known GRQs ("the GRQ catalogue"), and a subset of small (size…

Astrophysics of Galaxies · Physics 2022-04-20 Mousumi Mahato , Pratik Dabhade , D. J. Saikia , Francoise Combes , Joydeep Bagchi , Luis C. Ho , Somak Raychaudhury

We investigate the clustering properties of 45441 radio-quiet quasars (RQQs) and 3493 radio-loud quasars (RLQs) drawn from a joint use of the Sloan Digital Sky Survey (SDSS) and Faint Images of the Radio Sky at 20 cm (FIRST) surveys in the…

Astrophysics of Galaxies · Physics 2017-04-12 E. Retana-Montenegro , H. J. A. Röttgering

The FIRST Radio Survey provides a new resource for constructing a large quasar sample. With source positions accurate to better than 1\arcsec\ and a point source sensitivity limit of 1 mJy, it reaches 50 times deeper than previous radio…

We present the first results from a major HST WFPC2 imaging study aimed at providing the first statistically meaningful comparison of the morphologies, luminosities, scalelengths and colours of the host galaxies of radio-quiet quasars,…

Astrophysics · Physics 2008-11-26 R. J. McLure , J. S. Dunlop , M. J. Kukula , S. A. Baum , C. P. O'Dea , D. H. Hughes

We tested the effectiveness of radio selection to discover heavily obscured AGNs, particularly at high-z, and we measured their abundance for the first time from a radio perspective. We consider the radio sources detected in the J1030…