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相关论文: Updated Estimates of Global Cosmological Parameter…

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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…

天体物理学 · 物理学 2009-10-31 E. 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,…

天体物理学 · 物理学 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…

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

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…

天体物理学 · 物理学 2011-05-23 Asantha R. Cooray

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…

天体物理学 · 物理学 2009-11-07 Ruth A. Daly , Matthew P. Mory , Erick J. Guerra

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…

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…

天体物理学 · 物理学 2007-05-23 Greg. F. Wellman , 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…

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…

天体物理学 · 物理学 2010-11-19 Ruth A. Daly , E. J. Guerra

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…

星系天体物理 · 物理学 2019-02-27 J. J. Condon , A. M. Matthews , J. J. Broderick

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…

天体物理学 · 物理学 2007-08-09 Ruth Daly , C. O'Dea , P. Kharb , S. Baum , Kenneth Freeman , Matthew Mory

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…

天体物理学 · 物理学 2009-11-07 L. Van Waerbeke , Y. Mellier , R. Pello , U-L. Pen , H. J. McCracken , B. Jain

We have re-examined an ancient VLBI survey of ultra-comact radio sources at 2.29 GHz, which gave fringe amplitudes for 917 such objects with total flux density >0.5 Jy approximately. A number of cosmological investigations based upon this…

天体物理学 · 物理学 2009-11-11 J C Jackson , A L Jannetta

The ages of two old galaxies (53W091, 53W069) at high redshifts are used to constrain the value of the cosmological constant in a flat universe ($\Lambda$CDM) and the density parameter $\Omega_M$ in Friedmann-Robertson-Walker (FRW) models…

天体物理学 · 物理学 2009-10-31 J. S. Alcaniz , J. A. S. Lima

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…

天体物理学 · 物理学 2007-05-23 Ofer Lahav

Using a new radio sample, 6C* designed to find radio galaxies at z > 4 along with the complete 3CRR and 6CE sample we extend the radio galaxy K-z relation to z~4.5. The 6C* K-z data significantly improve delineation of the K-z relation for…

天体物理学 · 物理学 2022-03-02 Matt J. Jarvis , Steve Rawlings , Steve Eales , Katherine M. Blundell , Chris J. Willott

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…

宇宙学与河外天体物理 · 物理学 2021-05-17 Darshan Kumar , Deepak Jain , Shobhit Mahajan , Amitabha Mukherjee , Nisha Rani

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…

宇宙学与河外天体物理 · 物理学 2015-09-28 Shuo Cao , Marek Biesiada , Xiaogang Zheng , Zong-Hong Zhu

Three different methods of measuring cosmology with gamma-ray bursts (GRBs) have been proposed since a relation between the $\gamma$-ray energy $E_{\gamma} $ of a GRB jet and the peak energy $E_p$ of the $\nu F_{\nu}$ spectrum in the burst…

天体物理学 · 物理学 2009-11-10 D. Xu , Z. G. Dai , E. W. Liang

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,…

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