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Related papers: The EMSS Radio Loud Quasar Sample

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Different properties of quasars may be observed and analysed through the many ranges of the electromagnetic spectrum. Pioneering studies showed that an "H-R diagram" for quasars was needed to organize these data, and that more than two…

Astrophysics of Galaxies · Physics 2021-12-03 Alice Deconto-Machado , Ascensión del Olmo , Paola Marziani , Jaime Perea , Giovanna Stirpe

We predict that the UV bump spectrum of quasars extends into the soft X-ray range with a steep power law. For radio-louds, the spectral index is alpha_s ~ 1.7 (S_nu = S_o nu^-alpha), and for radio-quiets it should be somewhat steeper…

Astrophysics · Physics 2007-05-23 K. Mannheim , M. Schulte , J. Rachen

We present Spitzer Space Telescope photometry of 18 Sloan Digital Sky Survey (SDSS) quasars at 2.7 <= z <= 5.9 which have weak or undetectable high-ionization emission lines in their rest-frame ultraviolet (UV) spectra (hereafter weak-lined…

We present 6-GHz Very Large Array radio images of 70 gravitational lens systems at 300-mas resolution, in which the source is an optically-selected quasar, and nearly all of which have two lensed images. We find that about in half of the…

Astrophysics of Galaxies · Physics 2024-04-05 Neal Jackson , Shruti Badole , Thomas Dugdale , Hannah R. Stacey , Philippa Hartley , J. P. McKean , .

We report on our XMM observations of the high redshift quasars BR 2237--0607 (z=4.558) and BR 0351--1034 (z=4.351), together with 14 other z>4 objects found in the XMM public archive. Contrary to former reports, we do not find high redshift…

Astrophysics · Physics 2010-11-11 D. Grupe , S. Mathur , B. Wilkes , P. Osmer

We searched for high-z quasars within the X-ray source population detected in the contiguous $\sim 140^2$ eFEDS field observed by eROSITA during the performance verification phase. We collected the available spectroscopic information in the…

We have produced the next generation of quasar spectral energy distributions (SEDs), essentially updating the work of Elvis et al. (1994) by using high-quality data obtained with several space and ground-based telescopes, including NASA's…

(Abridged). We explore the fraction of radio loud quasars in the eHAQ+GAIA23 sample, which contains quasars from the High A(V) Quasar (HAQ) Survey, the Extended High A(V) Quasar (eHAQ) Survey, and the Gaia quasar survey. All quasars in this…

Astrophysics of Galaxies · Physics 2024-01-08 S. Vejlgaard , J. P. U. Fynbo , K. E. Heintz , J. -K. Krogager , P. Møller , S. J. Geier , L. Christensen , G Ma

We present the X-ray properties of a sample of 17 radio sources observed with the Chandra X-ray Observatory as part of a project aimed at studying the X-ray emission from their radio jets. In this paper, we concentrate on the X-ray…

Quasar feedback is a key ingredient in shaping galaxy evolution. A rare population of extremely red quasars (ERQs) at $z=2-3$ are often associated with high-velocity [O III]$\lambda5008$ outflows and may represent sites of strong feedback.…

Astrophysics of Galaxies · Physics 2024-08-13 Yilun Ma , Andy Goulding , Jenny E. Greene , Nadia L. Zakamska , Dominika Wylezalek , Yan-Fei Jiang

X-ray observations provide a unique probe of the accretion disk corona of supermassive black holes (SMBHs). In this paper, we present a uniform \emph{Chandra} X-ray data analysis of a sample of 152 $z\geq4.5$ quasars. We firmly detect 46…

High Energy Astrophysical Phenomena · Physics 2021-05-26 Jiang-Tao Li , Feige Wang , Jinyi Yang , Joel N. Bregman , Xiaohui Fan , Yuchen Zhang

We are conducting an X-ray survey of flat spectrum radio quasars (FSRQs) with extended radio structures. We summarize our results from the first stage of our survey, then we present findings from its continuation. We have discovered jet…

This paper reports on the extreme ultraviolet (EUV) spectrum of three low redshift ($z \sim 0.6$) radio loud quasars, 3C 95, 3C 57 and PKS 0405-123. The spectra were obtained with the Cosmic Origins Spectrograph (COS) of the Hubble Space…

Astrophysics of Galaxies · Physics 2016-04-27 Brian Punsly , Cormac Reynolds , Paola Marziani , Christopher P. O'Dea

We present deep (265 ks) Chandra X-ray observations of PSO J352.4034$-$15.3373, a quasar at z=5.831 that, with a radio-to-optical flux ratio of R>1000, is one of the radio-loudest quasars in the early universe and is the only quasar with…

Unified schemes of radio sources, which account for different types of radio AGN in terms of anisotropic radio and optical emission, together with different orientations of the ejection axis to the line of sight, have been invoked for many…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Neal Jackson , I. W. A. Browne

Broad absorption line quasars (BAL QSOs) belong to a class of objects not well-understood as yet. Their UV spectra show BALs in the blue wings of the UV resonance lines, owing to ionized gas with outflow velocities up to 0.2 c. They can…

Cosmology and Nongalactic Astrophysics · Physics 2013-06-17 G. Bruni , D. Dallacasa , K. -H. Mack , F. M. Montenegro-Montes , J. I. González-Serrano , J. Holt , F. Jiménez-Luján

We performed an observational program with the X-ray satellite BeppoSAX to study objects with extreme synchrotron peak frequencies (nu_peak > 1 keV). Of the seven sources observed, four showed peak frequencies in the range 1-5 keV, while…

We present a detailed analysis of a sample of radio-detected quasars, obtained by matching together objects from the FIRST and 2dF Quasar Redshift Surveys. The dataset consists of 113 sources, spanning a redshift range 0.3 < z < 2.2, with…

Astrophysics · Physics 2009-11-07 M. Cirasuolo , M. Magliocchetti , A. Celotti , L. Danese

We present the study on the X-ray emission for a sample of radio-detected quasars constructed from the cross-matches between SDSS, FIRST catalogs and XMM-Newton archives. A sample of radio-quiet SDSS quasars without FIRST radio detection is…

High Energy Astrophysical Phenomena · Physics 2021-02-10 Minhua Zhou , Minfeng Gu

We give an overview of our recent integral-field-unit spectroscopy of luminous extended emission-line regions (EELRs) around low-redshift quasars, including new observations of 5 fields. Previous work has shown that the most luminous EELRs…

Astrophysics · Physics 2008-12-18 Hai Fu , Alan Stockton
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