中文
相关论文

相关论文: The QSO variability-luminosity-redshift relation

200 篇论文

A fundamental prediction of relativistic cosmologies is that, due to the expansion of space, observations of the distant cosmos should be time dilated and appear to run slower than events in the local universe. Whilst observations of…

宇宙学与河外天体物理 · 物理学 2023-06-08 Geraint F. Lewis , Brendon J. Brewer

We investigate the relationship between the optical variability of galaxies and their distances from the centre of the Virgo Cluster using Palomar Transient Factory data. We define the ratio between the standard deviation of the galaxy…

星系天体物理 · 物理学 2020-06-17 Fan Yang , Richard J. Long , Su-Su Shan , Jun-Qiang Ge , Rui Guo , Bo Zhang , Ji-Hua Gao , Xiang Ji , Ji-Feng Liu

The X-ray variability of the Active Galactic Nuclei (AGN) has been most often investigated with studies of individual, nearby, sources, and only a few ensemble analyses have been applied to large samples in wide ranges of luminosity and…

宇宙学与河外天体物理 · 物理学 2011-12-21 F. Vagnetti , S. Turriziani , D. Trevese

We derive an analytic expression for the two-point correlation function in redshift space which (i) is nonlinear; (ii) is valid on the full sky, i.e. the distant-observer limit is not assumed; (iii) can account for the effect of…

宇宙学与河外天体物理 · 物理学 2023-11-08 Lawrence Dam , Camille Bonvin

Recent advancements have shown tensions between observations and our current understanding of the Universe. Such observations may include the $H_o$ tension and massive galaxies at high redshifts that are older than what traditional galaxy…

宇宙学与河外天体物理 · 物理学 2024-08-16 Lior Shamir

Interactions between cosmic ray protons and the photons of the cosmic microwave background radiation, as well as the expansion of the universe, cause cosmic rays to lose energy in a way that depends on the distance from the cosmic nray…

We present a formulation of observed number density fluctuations of gravitational-wave (GW) sources in a three dimensional space. In GW observations, redshift identification for each GW source is a challenging issue, in particular, for high…

宇宙学与河外天体物理 · 物理学 2021-02-03 Toshiya Namikawa

We have observed nine QSOs with redshifts 0.85 to 4.16 at near-IR wavelengths with the adaptive optics bonnette of the Canada-France-Hawaii telescope. Exposure times ranged from 1500 to 24000s (mostly near 7000s) in J, H, or K bands, with…

天体物理学 · 物理学 2009-10-31 J. B. Hutchings , D. Crampton , S. L. Morris , D. Durand , E. Steinbring

We extend previous analyses of wide-angle correlations in the galaxy power spectrum in redshift space to include all general relativistic effects. These general relativistic corrections to the standard approach become important on large…

宇宙学与河外天体物理 · 物理学 2015-09-17 Daniele Bertacca , Roy Maartens , Alvise Raccanelli , Chris Clarkson

We examine the effects of the linear and the cosmological redshift-space distortions on the power spectrum of cosmological objects on a light cone. We develop theoretical formulae for the power spectrum in linear theory of density…

天体物理学 · 物理学 2009-10-31 Hiroaki Nishioka , Kazuhiro Yamamoto

We investigate the dependence of galaxy clustering on luminosity and stellar mass in the redshift range 0.5<z<1.1, using the first ~55000 redshifts from the VIMOS Public Extragalactic Redshift Survey (VIPERS). We measured the redshift-space…

We have investigated the spatial distribution of quasars and its relationship with redshift by using the two-point correlation function, the variance of cell counts and the conditional density as a function of redshift. By comparing our…

天体物理学 · 物理学 2007-05-23 P. Andreani , S. Cristiani , F. La Franca

The detection of rapid variability on a time-scale of hours in radio-quiet quasars (RQQSOs) could be a powerful discriminator between starburst, accretion disc and relativistic jet models of these sources. This paper contains an account of…

天体物理学 · 物理学 2009-10-30 M. Rabbette , B. McBreen , N. Smith , S. Steel

We demonstrate that local, scale-dependent non-Gaussianity can generate cosmic variance uncertainty in the observed spectral index of primordial curvature perturbations. In a universe much larger than our current Hubble volume, locally…

宇宙学与河外天体物理 · 物理学 2015-06-16 Joseph Bramante , Jason Kumar , Elliot Nelson , Sarah Shandera

We compiled a sample of 60 quasars with spectroscopy on at least six epochs from the Sloan Digital Sky Survey (SDSS) to study the variabilities of the spectral shape, the continuum and the emission lines luminosity. In this paper, we…

宇宙学与河外天体物理 · 物理学 2015-06-16 Hengxiao Guo , Minfeng Gu

Using PSPC {\it Rosat} data, we measure x-ray surface brightness profiles, size and luminosity of the Butcher-Oemler (BO) sample of clusters of galaxies. The cluster x-ray size, as measured by the Petrosian r_{\eta=2} radius, does not…

天体物理学 · 物理学 2009-10-31 S. Andreon , S. Ettori

We present a quantitative study of the far-ultraviolet (FUV) and optical morphology in 32 nearby galaxies and estimate the ``morphological k-correction'' expected if these objects were observed unevolved at high redshift. Using the common…

天体物理学 · 物理学 2009-11-06 L. E. Kuchinski , Barry F. Madore , Wendy L. Freedman , M. Trewella

The polarization dependence of nonequilibrium transitions in a multistable cavity-polariton system is studied under a nanosecond long resonant optical excitation at the normal and magic angle incidences with various polarizations of the…

We calculate simultaneously the radio and optical luminosity evolutions of quasars, and the distribution in radio loudness R defined as the ratio of radio and optical luminosities, using a flux limited data set containing 636 quasars with…

宇宙学与河外天体物理 · 物理学 2015-05-27 J. Singal , V. Petrosian , A. Lawrence , L. Stawarz

Measurements of the baryonic acoustic oscillation (BAO) peak in the redshift-space correlation function yield the angular diameter distance D_A(z) and the Hubble parameter H(z) as a function of redshift, constraining the properties of dark…

宇宙学与河外天体物理 · 物理学 2014-11-18 Jaiyul Yoo , Jordi Miralda-Escudé
‹ 上一页 1 8 9 10 下一页 ›