Related papers: Quantized Redshift and its significance for recent…
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…
The wavelength dependence of atmospheric refraction causes differential chromatic refraction (DCR), whereby objects imaged at different optical/UV wavelengths are observed at slightly different positions in the plane of the detector. Strong…
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…
This year marks the 20th anniversary of the effective beginning of large, systematic redshift surveys of galaxies. These surveys have had a major impact on observational cosmology and on our current understanding of large-scale structures…
Periodically variable quasars have been suggested as close binary supermassive black holes. We present a systematic search for periodic light curves in 625 spectroscopically confirmed quasars with a median redshift of 1.8 in a 4.6 deg$^2$…
The quantification of the redshifts of the lines observed in the spectra of the quasars and the galaxies (the redshifts of their lines have some of the values given by the formula z=a+0.062m where a depends on the object, and m is an…
Proximity zones of high-redshift quasars are unique probes of their central supermassive black holes as well as the intergalactic medium in the last stages of reionization. We present 22 new measurements of proximity zones of quasars with…
Quasars accreting at very high rates are believed to be prime movers of galactic evolution because of their high radiative and mechanical output. The study presented in this paper investigates a sample of six highly accreting quasars at…
We present an improved photometric error analysis for the 7,100 CRTS (Catalina Real-Time Transient Survey) optical light curves for quasars from the SDSS (Sloan Digital Sky Survey) Stripe 82 catalogue. The SDSS imaging survey has provided a…
The quasar sample of the fourteenth data release of the Sloan Digital Sky Survey (SDSS-IV DR14) is used to determine the cosmic homogeneity scale in the redshift range $0.80<z<2.24$. We divide the sample into 4 redshift bins, each one with…
Quasar-driven galactic outflows are a major driver of the evolution of massive galaxies. We report observations of a powerful galactic-scale outflow in a $z=3$ extremely red, intrinsically luminous ($L_{\rm bol}\simeq 5\times 10^{47}$erg…
We have made radio observations of 87 optically selected quasars at 5 GHz with the VLA in order to measure the radio power for these objects and hence determine how the fraction of radio-loud quasars varies with redshift and optical…
High-redshift quasars typically have their redshift determined from rest-frame ultraviolet (UV) emission lines. However, these lines, and more specifically the prominent C IV $\lambda 1549$ emission line, are typically blueshifted yielding…
We investigate the potential and accuracy of clustering-based redshift estimation using the method proposed by M\'enard et al. (2013). This technique enables the inference of redshift distributions from measurements of the spatial…
In this paper, we address the problem of spectroscopic redshift estimation in Astronomy. Due to the expansion of the Universe, galaxies recede from each other on average. This movement causes the emitted electromagnetic waves to shift from…
UGC 8584 was selected by a computer program as having a number of quasars around it that obeyed the Karlsson periodicity in its reference frame. On closer examination 9 of the nearest 10 quasars turned out to be extremely close to the…
A simple estimate of the photometric redshift would prove invaluable to forthcoming continuum surveys on the next generation of large radio telescopes, as well as mitigating the existing bias towards the most optically bright sources. While…
The redshift range from 2.2 to 3, is known as the 'redshift desert' of quasars because quasars with redshift in this range have similar optical colors as normal stars and are thus difficult to be found in optical sky surveys. A quasar…
We report the investigation of spatial distribution of quasars using two different methods: the statistical study by means of 2-point correlation function and direct search for structures such as previously reported Large Quasar Groups.…
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.…