相关论文: Steep functions in astronomy: the RQSO z-cutoff de…

A picture has emerged connecting QSOs with Sub-Millimetre Galaxies (SMGs) through an evolutionary sequence in which forming galaxies are initially FIR-luminous but X-ray weak, similar to known SMGs. As the black hole and spheroid grow with…

We use data from the Parkes Half-Jansky Flat-Spectrum (PHJFS) sample (Drinkwater et al. 1997) to constrain the cosmic evolution in the co-moving space density of radio sources in the top decade of the flat-spectrum radio luminosity function…

In the unusual intrinsic QSO redshift models, QSOs are ejected by active galaxies with periodic non-cosmological reshifts, thus QSOs are generally associated with active galaxies, and certain structures will be revealed in the QSO redshift…

Red quasi-stellar objects (QSOs) are a subset of the luminous end of the cosmic population of active galactic nuclei (AGN), most of which are reddened by intervening dust along the line-of-sight towards their central engines. In recent work…

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 Great Observatories Origins Deep Survey provides significant constraints on the space density of less luminous QSOs at high redshift, which is particularly important to understand the interplay between the formation of galaxies and…

Three high-redshift (z=2) and high luminosity (M_B < -28 mag for Ho = 50, qo=0.5) QSOs, two radio-quiet one radio-loud, were imaged in R, I and K bands. The luminosities, colours and sizes of the hosts overlap with those of actively…

We obtain a sample of 87 radio-loud QSOs in the redshift range 3.6<z<4.4 by cross-correlating sources in the FIRST radio survey S{1.4GHz} > 1 mJy with star-like objects having r <20.2 in SDSS Data Release 7. Of these 87 QSOs, 80 are…

Recent work on red and blue quasi-stellar objects (QSOs) has identified peculiar number distributions as a function of radio loudness that we explore and attempt to explain from the perspective of a picture in which a subset of the…

We use the K-z relation for radio galaxies to illustrate why it has proved difficult to obtain definitive cosmological results from studies based entirely on catalogues of the brightest radio sources, e.g. 3C. To improve on this situation…

Together with the CMB, the three sources of information that astronomers have at high redshift as probes of the formation and evolution of the LSS are QSOs, galaxies and absorbers observed in the spectrum of distant background objects. In…

We review the statistical properties of the main populations of radio sources, as emerging from radio and millimeter sky surveys. Recent determinations of local luminosity functions are presented and compared with earlier estimates still in…

We examine the black hole mass - galaxy bulge relationship in high-redshift QSOs. Black hole masses are derived from the broad emission lines, and the host galaxy stellar velocity dispersion sigma is estimated from the widths of the radio…

We have obtained complete redshift information for a sample of 442 radio-loud quasars with flux densities S(11cm) >= 0.25Jy. These come from a completely-identified sample of 878 flat-spectrum radio sources, so there is no optical magnitude…

We report the discovery of a candidate dual QSO at z=1.889, a redshift that is in the era known as "cosmic noon" where most of the Universe's black hole and stellar mass growth occurred. The source was identified in Hubble Space Telescope…

Astronomical or cosmological redshifts are an observable property of extragalactic objects and have historically been wholly attributed to the recessional velocity of that object. The question of other, or intrinsic, components of the…

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…

Two new samples of QSOs have been constructed from recent surveys to test the hypothesis that the redshift distribution of bright QSOs is periodic in $\log(1+z)$. The first of these comprises 57 different redshifts among all known close…

We discuss broad- and narrow-band imaging of 7 arcmin fields of 14 QSOs with redshift ~1.1. The narrow-band filters were chosen to detect redshifted [O II] 3727A, and the broad bands are R and I, which correspond to rest wavelengths…

This paper presents a new grid-based method for investigating the evolution of the steep-spectrum radio luminosity function, with the aim of quantifying the high-redshift cut-off suggested by previous work. To achieve this, the Combined…