English
Related papers

Related papers: Analysis of quasar magnitudes

200 papers

Most physical properties derived for quasars, as single entities or as a population, depend upon the cosmology assumed. In this paper, we calculate the quasar luminosity function and some related quantities for a flat universe dominated by…

Astrophysics · Physics 2009-10-22 Sangeeta Malhotra , Edwin L Turner

In this paper we examine magnitudes of quasars as a function of redshift in different frequency ranges (u,g,r,i,z). We show that on the smoothed curves mag(Z) in frequency ranges u,g,r there are characteristic features both similar for all…

General Physics · Physics 2012-12-27 Iurii Kudriavtcev

We introduce a phenomenological investigation of the evolution and large scale distribution of quasars using a modified version of the Field and Colgate gravitational contraction model for proto-galaxies. By studying the distribution of…

Astrophysics · Physics 2007-05-23 S. Nasiri , V. Rezania

It is considered that quasars evolve into normal galaxies by means of expansion of matter. The order of magnitude of the expansion velocity can be estimated. The Doppler shift caused by such expansion explains the supposed variation of the…

Astrophysics · Physics 2007-05-23 Mario Everaldo de Souza

We search for the most suitable set of cosmological parameters that describes the observable universe. The search includes the possibility of quintessential flat universes, i.e., the analysis is restricted to the determination of the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Ariel Zandivarez , Hector J. Martinez

The theoretically expected amplitude of the associations of background quasars with foreground galaxies as a result of gravitational lensing has been updated in this paper. Since the galactic matter alone yields an amplitude of quasar…

Astrophysics · Physics 2008-11-26 Zong-Hong Zhu , Xiang-Ping Wu , Li-Zhi Fang

A relation between the variational slope, $s_F$ , and the mean absolute magnitude, $\langle M \rangle$, in the light curves of 58 spectroscopically confirmed quasars is measured with a dispersion of 0.15dex. Assuming it holds for quasars in…

Cosmology and Nongalactic Astrophysics · Physics 2022-06-30 Rance Solomon , Dejan Stojkovic

Quasars signal a unique phase of galaxy evolution -- when massive spheroids are rapidly being assembled, forming stars and growing their central super-massive black holes. Measurements of the metal abundances around quasars provide unique…

Astrophysics · Physics 2007-05-23 Fred Hamann , Craig Warner , Matthias Dietrich , Gary Ferland

The absence of any wide-separation gravitational lenses in the Large Bright Quasar Survey is used to place limits on the population of cluster-sized halos in the universe, and hence constrain a number of cosmological parameters. The results…

Astrophysics · Physics 2009-10-31 Daniel J. Mortlock , Rachel L. Webster

Contemporary multidimensional cosmological theories predict different variations of fundamental physical constants in course of the cosmological evolution. On the basis of the QSO spectra analysis, we show that the fine-structure constant…

Astrophysics · Physics 2007-05-23 D. A. Varshalovich , A. Y. Potekhin , A. V. Ivanchik , V. E. Panchuk , K. M. Lanzetta

The laws of physics have a set of fundamental constants, and it is generally admitted that only dimensionless combinations of constants have physical significance. These combinations include the electromagnetic and gravitational fine…

Cosmology and Nongalactic Astrophysics · Physics 2013-04-29 James Rich

We investigate recent claims by Secrest et al. of an anomalously large amplitude of the dipole in the distribution of CatWISE-selected quasars on the sky. Two main issues indicate that the systematic uncertainties in the derived…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-22 Arefe Abghari , Emory F. Bunn , Lukas T. Hergt , Boris Li , Douglas Scott , Raelyn M. Sullivan , Dingchen Wei

Quasar outflows may play a crucial role in regulating the host galaxy, although the spatial scale of quasar outflows remain a major enigma, with their acceleration mechanism poorly understood. The kinematic information of outflow is the key…

Quasars are thought to be powered by the infall of matter onto a supermassive black hole at the centre of massive galaxies. As the optical luminosity of quasars exceeds that of their host galaxy, disentangling the two components can be…

The vast majority of the literature dealing with quantum dynamics is concerned with linear evolution of the wave function or the density matrix. A complete dynamical description requires a full understanding of the evolution of measured…

We consider the impact of quasar outflows on structure formation. Such outflows are potentially more important than galactic winds, which appear insufficient to produce the level of preheating inferred from X-ray observations of galaxy…

Astrophysics · Physics 2011-07-18 Evan Scannapieco , S. Peng Oh

Recent results have questioned the description of the QSO luminosity function in terms of a pure luminosity evolution and call for a luminosity dependent luminosity evolution. Measurements of the QSO clustering amplitude and evolution allow…

Astrophysics · Physics 2007-05-23 S. Cristiani , F. La Franca , P. Andreani

In this paper we show that to explain the observed distribution of amplitudes in a large sample of quasar lightcurves, a significant contribution from microlensing is required. This implies the existence of a cosmologically distributed…

Cosmology and Nongalactic Astrophysics · Physics 2022-04-21 M. R. S. Hawkins

In a popular scenario for the coevolution of massive black holes and galaxies, major mergers of gas-rich galaxies fuel vigorous star formation and obscured (type 2) quasar activity until energy feedback from the active galactic nucleus…

Astrophysics of Galaxies · Physics 2019-03-20 Jinyi Shangguan , Luis C. Ho

The accretion of a cloud of hydrogen at the surface of a small, heavy star produces a high energy mostly dissipated by electromagnetic radiation. The combination of the absorption and the redshift of this radiation by hydrogen explains all…

Astrophysics · Physics 2007-05-23 Jacques Moret-Bailly
‹ Prev 1 2 3 10 Next ›