English
Related papers

Related papers: Global Cosmological Parameters Determined Using Cl…

200 papers

A sample of 20 powerful extended radio galaxies with redshifts between zero and two were used to determine constraints on global cosmological parameters. Data for six radio sources were obtained from the VLA archive, analyzed, and combined…

Astrophysics · Physics 2015-06-24 Erick J. Guerra , Ruth A. Daly , Lin Wan

Fourteen classical double radio galaxies with redshifts between zero and two were used to determine the cosmological parameters $\Omega_m$, $\Omega_{\Lambda}$, and $\Omega_k$, where these are the normalized values of the mean mass density,…

Astrophysics · Physics 2007-05-23 Ruth A. Daly , E. J. Guerra , Lin Wan

Physical sizes of extended radio galaxies can be employed as a cosmological "standard ruler", using a previously developed method. Eleven new radio galaxies are added to our previous sample of nineteen sources, forming a sample of thirty…

Astrophysics · Physics 2009-02-02 Ruth A. Daly , Matthew P. Mory , C. P. O'Dea , P. Kharb , S. Baum , E. J. Guerra , S. G. Djorgovski

There are many different approaches to using observations to constrain or determine the global cosmological parameters that describe our universe. Methods that rely upon a determination of the coordinate distance to high-redshift sources…

Astrophysics · Physics 2009-11-07 Ruth A. Daly , Matthew P. Mory , Erick J. Guerra

We calculate the expected number of strongly lensed radio sources in a sample of 6500 sources observed with the Very Large Array as part of the Cosmic Lens All Sky Survey (CLASS) during the first two sessions of its observations. A…

Astrophysics · Physics 2011-05-23 Asantha R. Cooray

The radio properties of powerful extended radio sources may be used to estimate the ambient gas density in the vicinity of radio lobes. A sample of 27 radio lobes from 14 radio galaxies and of 14 radio lobes from 8 radio loud quasars was…

Astrophysics · Physics 2007-05-23 Greg. F. Wellman , Ruth. A. Daly

We derive constraints on cosmological parameters and the properties of the lensing galaxies from gravitational lens statistics based on the final Cosmic Lens All Sky Survey (CLASS) data. For a flat universe with a classical cosmological…

Powerful extended radio galaxies like Cygnus A can be used for cosmological tests. The characteristic, time-independent length $D_*$ for several radio sources is calculated and compared to the average physical length for a sample of radio…

Astrophysics · Physics 2007-05-23 Erick J. Guerra , Ruth A. Daly

We derive constraints on cosmological parameters using the power spectrum of galaxy clustering measured from the final two-degree field galaxy redshift survey (2dFGRS) and a compilation of measurements of the temperature power spectrum and…

The properties of a sample of 31 very powerful classical double radio galaxies with redshifts between zero and 1.8 are studied. The source velocities, beam powers, ambient gas densities, total lifetimes, and total outflow energies are…

Astrophysics · Physics 2007-08-09 Ruth Daly , C. O'Dea , P. Kharb , S. Baum , Kenneth Freeman , Matthew Mory

Fanaroff-Riley type IIb (FR IIb) radio galaxies provide a modified standard yardstick that allows constraints to be placed on global cosmological parameters. A sample of 20 FR IIb radio galaxies with redshifts between 0 and 2 are compared…

Astrophysics · Physics 2010-11-19 Ruth A. Daly , E. J. Guerra

We present a maximum likelihood analysis of cosmological parameters from measurements of the aperture mass up to 35 arcmin, using simulated and real cosmic shear data. A four-dimensional parameter space is explored which examines the mean…

Astrophysics · Physics 2009-11-07 L. Van Waerbeke , Y. Mellier , R. Pello , U-L. Pen , H. J. McCracken , B. Jain

Data from Type Ia supernovae, along with X-ray cluster estimates of the universal baryon fraction and Big Bang Nucleosynthesis (BBN) determinations of the baryon-to-photon ratio, are used to provide estimates of several global cosmological…

Astrophysics · Physics 2007-05-23 G. Steigman , T. P. Walker , A. Zentner

We identified 15,658 NVSS radio sources among the 55,288 2MASX galaxies brighter than $k_\mathrm{20fe} = 12.25$ at $\lambda = 2.16\,\mu\mathrm{m}$ and covering the $\Omega =7.016$ sr of sky defined by J2000 $\delta > -40^\circ$ and $\vert b…

Astrophysics of Galaxies · Physics 2019-02-27 J. J. Condon , A. M. Matthews , J. J. Broderick

Understanding diffuse Galactic radio emission is interesting both in its own right and for minimizing foreground contamination of cosmological measurements. Cosmic Microwave Background experiments have focused on frequencies > 10 GHz,…

Strong gravitational lensing along with the distance sum rule method can constrain both cosmological parameters as well as density profiles of galaxies without assuming any fiducial cosmological model. To constrain galaxy parameters and…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-17 Darshan Kumar , Deepak Jain , Shobhit Mahajan , Amitabha Mukherjee , Nisha Rani

We review observational tests for the homogeneity of the Universe on large scales. Redshift and peculiar velocity surveys, radio sources, the X-Ray Background, the Lyman-$\alpha$ forest and the Cosmic Microwave Background are used to set…

Astrophysics · Physics 2007-05-23 Ofer Lahav

We review observational tests for the homogeneity of the Universe on large scales. Redshift and peculiar velocity surveys, radio sources, the X-Ray Background, the Lyman-alpha forest and the Cosmic Microwave Background are used to set…

Astrophysics · Physics 2016-08-30 Ofer Lahav

A new sample of very large angular size radio sources has been selected from the 1.4 GHz VLA surveys: FIRST and NVSS. This sample will be very useful for an observational constraint on the time evolution of double radio sources, especially…

Astrophysics · Physics 2009-11-06 J. Machalski , M. Jamrozy , S. Zola

Cosmological applications of the "redshift - angular size" test require knowledge of the linear size of the "standard rod" used. In this paper, we study the properties of a large sample of 140 milliarcsecond compact radio sources with flux…

Cosmology and Nongalactic Astrophysics · Physics 2015-09-28 Shuo Cao , Marek Biesiada , Xiaogang Zheng , Zong-Hong Zhu
‹ Prev 1 2 3 10 Next ›