相关论文: High-Redshift Quasars at the Highest Resolution: V…

From examination of only 4 deg^2 of sky in the NOAO Deep Wide-Field Survey (NDWFS) region, we have identified the first radio-loud quasar at a redshift z>6. The object, FIRST J1427385+331241, was discovered by matching the FLAMEX IR survey…

We performed high resolution radio observations of a new sample of ten BAL quasars using both the VLBA and EVN at 5 GHz. All the selected sources have balnicity indices (BI) more than 0 and radio flux densities less than 80 mJy at 1.4 GHz.…

Aims. We selected two radio quasars (J1036+1326 and J1353+5725) based on their 1.4-GHz radio structure, which is dominated by a bright central core and a pair of weaker and nearly symmetric lobes at ~10" angular separation. They are…

We present observations of 11 quasars, selected in the range z = 2.2-4.1, obtained with ESA's Superconducting Tunnel Junction (STJ) camera on the WHT. Using a single template quasar spectrum, we show that we can determine the redshifts of…

Some models of the expanding Universe predict that the astrometric proper motion of distant radio sources embedded in space-time are non-zero as the radial distance from observer to the source grows. Systematic proper motion effects would…

Although radio-quiet quasars (RQQs) constitute >90% of optically-identified quasar samples their radio properties are only poorly understood. In this paper we present the results of a multi-frequency VLA study of 27 low-redshift RQQs. We…

We present submillimetre (SCUBA) photometry of a sample of eight high-redshift (2.5 < z < 3.5) radio quasars from two redshift surveys: the TEXOX-1000, or TOOT, survey; and the 7C Redshift Survey (7CRS). Unlike the powerful high-redshift…

We investigate the frequency-dependent radio properties of the jet of the luminous high-redshift (z = 3.2) radio quasar PKS 1402+044 (J1405+0415) by means of radio interferometric observations. The observational data were obtained with the…

The luminous high-redshift (z=2.17) quasar S50836+710 has been observed in October 1997 with the VSOP at 1.6 GHz and 5 GHz. We report here a previously unpublished image made from the data at 1.6 GHz and compare the structure of a…

We present photometric and spectroscopic observations of 15 high-redshift quasars (z > 3.6) discovered from ~140 deg^2 of five-color (u'g'r'i'z') imaging data taken by the Sloan Digital Sky Survey (SDSS) during its commissioning phase. The…

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 spectroscopic measurements for 226 sources from the Gemini Near Infrared Spectrograph - Distant Quasar Survey (GNIRS-DQS). Being the largest uniform, homogeneous survey of its kind, it represents a flux-limited sample ($m_{i}$…

We present the discovery of a large extended radio jet associated with the extremely radio-loud quasar J1601+3102 at $z\sim5$ from sub-arcsecond resolution imaging at 144 MHz with the LOFAR International Telescope. These large radio lobes…

We carry out a series of deep Karl G. Jansky Very Large Array (VLA) S-band observations of a sample of 21 quasars at $z\sim6$. The new observations expand the searches of radio continuum emission to the optically faint quasar population at…

Broad Absorption Line Quasars (BAL QSOs) have been found to be associated with extremely compact radio sources. These reduced dimensions can be either due to projection effects or these objects might actually be intrinsically small.…

Red quasi-stellar objects (QSOs) are a subset of the quasar population with colours consistent with reddening due to intervening dust. Recent work has demonstrated that red QSOs show special radio properties that fundamentally distinguish…

The most luminous quasars at high redshift harbour the fastest-growing and most massive black holes in the early Universe. They are exceedingly rare and hard to find. Here, we present our search for the most luminous quasars in the redshift…

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…

The extremely high redshift (z=5.3) radio source SDSS J102623.61+254259.5 (J1026+2542) is among the most distant and most luminous radio-loud active galactic nuclei (AGN) known to date. Its one-sided radio jet structure on milli-arcsecond…

QSOs and radio-galaxies, together with the CMB, ``normal'' galaxies and clusters, represent the main source of information about the origin and evolution of the Large Scale Structure. They can be used either directly, as tracers of the…