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Related papers: The Redshifted Excess in Quasar C IV Broad Emissio…

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We aim to evaluate the behaviour of our 22 high-redshift (2.2 < z < 3.7) and high-luminosity (47.39 < Lbol < 48.36) quasars in the context of the 4-Dimensional Eigenvector 1. Our approach involves studying quasar physics through…

Astrophysics of Galaxies · Physics 2023-01-18 A. Deconto-Machado , A. del Olmo , P. Marziani , J. Perea , G. M. Stirpe

Red quasars are candidate young objects in an early transition stage of massive galaxy evolution. Our team recently discovered a population of extremely red quasars (ERQs) in the Baryon Oscillation Spectroscopic Survey (BOSS) that has a…

We present an observational study of 22 broad absorption line quasars (BAL QSOs) at $3\lesssim z \lesssim5$ based on optical/near-IR spectroscopy, aiming to investigate quasar winds and their effects. The near-IR spectroscopy covers the…

Astrophysics of Galaxies · Physics 2020-04-29 Weimin Yi , Wenwen Zuo , Jinyi Yang , Feige Wang , John Timlin , Catherine Grier , Xue-Bing Wu , Xiaohui Fan , Jin-Ming Bai

Extremely Red Quasars (ERQs) are thought to represent a brief episode of young quasar and galactic evolution characterized by rapid outflows and obscured growth due to dusty environments. We use new redshift measurements from CO and…

Astrophysics of Galaxies · Physics 2023-05-22 Jarred Gillette , Fred Hamann , Marie Wingyee Lau , Serena Perrotta

In this Letter, the properties of the extended radio emission form SDSS DR7 quasars with $0.4<z<0.8$ is studied. This low redshift sample is useful since any corresponding FIRST radio observations are sensitive enough to detect extended…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Brian Punsly , Shaohua Zhang

Quasar redshifts require the best possible precision and accuracy for a number of applications, such as setting the velocity scale for outflows as well as measuring small-scale quasar-quasar clustering. The most reliable redshift standard…

Astrophysics of Galaxies · Physics 2017-06-28 Michelle Mason , Michael Brotherton , Adam Myers

The radio properties of 11 obscured `radio-intermediate' quasars at redshifts z>~2 have been investigated using the European Very-Long-Baseline-Interferometry Network (EVN) at 1.66 GHz. A sensitivity of ~25 micro Jy per 14x17 mas2 beam was…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 H. -R. Kloeckner , A. Martinez-Sansigre , S. Rawlings , M. A. Garrett

Using a sample of $\simeq$144,000 quasars from the Sloan Digital Sky Survey data release 14 we investigate the outflow properties, evident both in absorption and emission, of high-ionization Broad Absorption Line (BAL) and non-BAL quasars…

Astrophysics of Galaxies · Physics 2020-03-19 Amy L. Rankine , Paul C. Hewett , Manda Banerji , Gordon T. Richards

We present 0.5-8.0 keV Chandra observations of six bright quasars that represent extrema in quasar emission-line properties -- three quasars each with small and large blueshifts of the CIV emission line with respect to the systemic redshift…

We studied the spectra of six $z \sim 2.2$ quasars obtained with the X-shooter spectrograph at the Very Large Telescope. The redshift of these sources and X-shooter's spectral coverage allow us to cover the rest spectral range $\sim1200 -…

We use optical and near-IR imaging to examine the properties of the significant excess population of K>=19 galaxies found in the fields of 31 z=1-2 radio-loud quasars by Hall, Green & Cohen (1998). The excess occurs on two spatial scales: a…

Astrophysics · Physics 2011-05-05 Patrick B. Hall , Richard F. Green

We investigate the correlations between spectral index, jet side and extent of the radio lobes for a sample of nearby FRII radio galaxies. In Dennett-Thorpe et al. (1997) we studied a sample of quasars and found that the high surface…

Astrophysics · Physics 2009-10-31 J. Dennett-Thorpe , A. H. Bridle , R. A. Laing , P. A. G. Scheuer

Chandra X-ray observations of the high redshift (z =1.532) radio-loud quasar 3C270.1 in 2008 February show the nucleus to have a power-law spectrum, Gamma = 1.66 +/- 0.08, typical of a radio-loud quasar, and a marginally-detected Fe Kalpha…

We have conducted observations of the environment around the z=2.15 radio loud quasar 1550-269 in search of distant galaxies associated either with it or the z=2.09 CIV absorber along its line of sight. Such objects will be distinguished by…

Astrophysics · Physics 2009-10-31 D. L. Clements

We analyse the rest-frame UV spectra of 2,531 high-redshift (3.5<z<4.0) quasars from the Sloan Digital Sky Survey DR16Q catalogue. In combination with previous work, we study the redshift evolution of the rest-frame UV line properties…

A recent Chandra observation of the nearby galaxy cluster Abell 585 has led to the discovery of an extended X-ray jet associated with the high-redshift background quasar B3 0727+409, a luminous radio source at redshift z=2.5. This is one of…

High Energy Astrophysical Phenomena · Physics 2016-01-13 A. Simionescu , Ł. Stawarz , Y. Ichinohe , C. C. Cheung , M. Jamrozy , A. Siemiginowska , K. Hagino , P. Gandhi , N. Werner

The interactions between radio jets and the interstellar medium play a defining role for the co-evolution of central supermassive black holes and their host galaxies, but observational constraints on these feedback processes are still very…

The elemental abundances in the broad-line regions of high-redshift quasars trace the chemical evolution in the nuclear regions of massive galaxies in the early universe. In this work, we study metallicity-sensitive broad emission-line flux…

A substantial fraction of quasars display broad absorption lines (BALs) in their rest-frame ultraviolet spectra. While the origin of BALs is thought to be related to the accretion disc wind, it remains unclear whether the observed ratio of…

High Energy Astrophysical Phenomena · Physics 2024-05-22 Takayuki J. Hayashi , Akihiro Doi , Hiroshi Nagai

We present Chandra X-ray observations of 14 radio-loud quasars at redshifts $3 < z < 4$, selected from a well-defined sample. All quasars are detected in the 0.5-7.0 keV energy band, and resolved X-ray features are detected in five of the…