English
Related papers

Related papers: Comparing different indicators of quasar orientati…

200 papers

We present Giant Metrewave Radio Telescope (GMRT) 323 MHz radio continuum observations toward 13 radio-loud quasars at $z>5$, sampling the low-frequency synchrotron emission from these objects. Among the 12 targets successfully observed, we…

Astrophysics of Galaxies · Physics 2020-09-16 Yali Shao , Jeff Wagg , Ran Wang , Chris L. Carilli , Dominik A. Riechers , Huib T. Intema , Axel Weiss , Karl M. Menten

The X-ray weakness of broad absorption line (BAL) quasars in comparison to non-BAL objects is possibly caused by the absorption of X-ray emission by the shielding material near the equatorial plane. On the other hand, the radio-loud BALQSOs…

Astrophysics of Galaxies · Physics 2015-06-23 M. Kunert-Bajraszewska , K. Katarzynski , A. Janiuk

The role of radio mode feedback in non radio-loud quasars needs to be explored in depth to determine its true importance. Its effects can be identified based on the evidence of interactions between the radio structures and the ambient…

The jet formation is thought to be closely connected with the mass of central supermassive black hole in Active Galactic Nuclei. The radio luminosity commonly used in investigating this issue is merely an indirect measure of the energy…

Astrophysics · Physics 2008-11-26 Yi Liu , Dong Rong Jiang , Min Feng Gu

The pulsar profile is characterised by two distinct emission components, the core and the cone. The standard model of a pulsar radio emission beam originating from dipolar magnetic fields, places the core at the centre surrounded by…

High Energy Astrophysical Phenomena · Physics 2022-03-30 Rahul Basu , Dipanjan Mitra , George I. Melikidze

We present submillimetre photometry of 11 3CR and 6CE radio quasars of similar 151-MHz radio luminosity and redshifts to the radio galaxies studied at 1.3<z<2 by Archibald et al. (2001). We detect all bar one quasar at 850 microns, and five…

Astrophysics · Physics 2009-11-07 Chris J. Willott , Steve Rawlings , Elese N. Archibald , James S. Dunlop

We use new 144 MHz observations over 5634 deg$^2$ from the LOFAR Two-metre Sky Survey (LoTSS) to compile the largest sample of uniformly-selected, spectroscopically-confirmed quasars from the 14th data release of the Sloan Digital Sky…

We present deep radio observations of the most distant complete quasar sample drawn from the Sloan Digital Sky Survey. Combining our new data with those from literature we obtain a sample which is ~100 per cent complete down to S_1.4GHz =…

Astrophysics · Physics 2009-11-11 M. Cirasuolo , M. Magliocchetti , G. Gentile , A. Celotti , S. Cristiani , L. Danese

Submillimeter (and in some cases millimeter) wavelength continuum measurements are presented for a sample of 40 active galactic nuclei (probably all quasars) lensed by foreground galaxies. The object of this study is to use the lensing…

Astrophysics · Physics 2009-11-07 Richard Barvainis , Rob Ivison

We searched the Hubble Space Telescope Cosmic Origins Spectrograph archive for ultraviolet spectra of 428 AGN to identify intrinsic NV absorption systems. We filtered out Type 2 AGN, blazars, and spectra that do not cover at least part of…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-20 Chris Culliton , Amber Roberts , Bryan DeMarcy , Sowgat Muzahid , Rajib Ganguly , Jane Charlton , Michael Eracleous , Toru Misawa

We present the complete set of ISOPHOT observations of 3CR radio galaxies and quasars, which are contained in the ISO Data Archive, providing 75 mid- and far-infrared spectral energy distributions (SEDs) between 5 and 200 micron. For 28…

We combine results from ROSAT, Chandra, and multifrequency VLBA observations of the Compact Steep Spectrum quasar 3C 48. We infer that the X-ray spectrum of the nucleus is made up of a soft, variable, steep-spectrum component, and harder,…

Astrophysics · Physics 2009-11-10 D. M. Worrall , M. J. Hardcastle , T. J. Pearson , A. C. S. Readhead

In active galactic nuclei, jet-driven feedback plays a significant role in influencing the properties of gas within their host galaxy and the circumgalactic medium. By combining observations from the Very Large Array Sky Survey, the Faint…

Astrophysics of Galaxies · Physics 2025-02-27 Chen ZF , Luis C. Ho

We discuss a probe of the contribution of wind-related shocks to the radio emission in otherwise radio-quiet quasars. Given 1) the non-linear correlation between UV and X-ray luminosity in quasars, 2) that such correlation leads to higher…

Obscuration in high-redshift quasi-stellar objects (QSO) has a profound impact on our understanding of the evolution of supermassive black holes across the cosmic time. An accurate quantification of its relevance is therefore mandatory. We…

Astrophysics of Galaxies · Physics 2024-02-06 A. Caccianiga , L. Ighina , A. Moretti , R. Brivio , S. Belladitta , D. Dallacasa , C. Spingola , M. J. Marchã , S. Antón

In this study, 36 cores (30 starless and 6 protostellar) identified in Orion were surveyed to search for inward motions. We used the Nobeyama 45 m radio telescope, and mapped the cores in the $J = 1\rightarrow0$ transitions of HCO$^+$,…

Determining the nature of emission processes at the heart of quasars is critical for understanding environments of supermassive black holes. One of the key open questions is the origin of long-wavelength emission from radio-quiet quasars.…

Astrophysics of Galaxies · Physics 2025-09-17 M. Rybak , D. Sluse , K. K. Gupta , M. Millon , E. Behar , F. Courbin , J. P. McKean , H. R. Stacey

I bring together evidence for the rapidity with which quasars' radio synchrotron lobe emission fades and for the intermittency with which jet plasma is ejected from individual quasars and radio galaxies and affirm the picture presented by…

Astrophysics · Physics 2008-03-06 Katherine Blundell

In this paper, based on a 2.29 GHz VLBI all-sky survey of 613 milliarcsecond ultra-compact radio sources with $0.0035<z<3.787$, we describe a method of identifying the sub-sample which can serve as individual standard rulers in cosmology.…

Cosmology and Nongalactic Astrophysics · Physics 2018-01-08 Shuo Cao , Marek Biesiada , John Jackson , Xiaogang Zheng , Yuhang Zhao , Zong-Hong Zhu

A new analysis of the connection between black-hole mass and radio luminosity in radio-selected flat-spectrum quasars (FSQ) is presented. In contrast to recent claims in the literature, we find no evidence that the black-hole masses of…

Astrophysics · Physics 2009-11-07 Matt J. Jarvis , Ross J. McLure
‹ Prev 1 4 5 6 7 8 10 Next ›