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Related papers: Cygnus A and Other 3CR Sources in Cosmological Tes…

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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…

Astrophysics · Physics 2009-10-31 E. J. Guerra , Ruth A. Daly , 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 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…

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

Immensely bright quasars and radio-loud active galactic nuclei (AGNs) provide an enticing opportunity to construct standard candles detectable up to the very early universe. An analytic theory is proposed to measure the distance to powerful…

Cosmology and Nongalactic Astrophysics · Physics 2020-07-24 Ross Turner , Stanislav Shabala

We present a comparison of radio observations of the archetypal powerful radio galaxy Cygnus A and 2-D numerical hydrodynamical simulations. We characterize some global trends in the observed radio properties and compare them with the…

Astrophysics · Physics 2009-11-10 J. C. Carvalho , R. A. Daly , M. P. Mory , C. P. O'Dea

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

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

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

The redshifts of faint radio galaxies identified with giant radio source candidates selected from the sample of Machalski et al. (2001) have been measured. Given the redshift, the projected linear size and radio luminosity are then…

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…

Some years ago (Jackson and Dodgson 1997) analysis of the angular-size/redshift relationship for ultra-compact radio sources indicted that for spatially flat universes the best choice of cosmological parameters was Omega_m=0.2 and…

Astrophysics · Physics 2009-11-10 J. C. Jackson

Radio continuum surveys can detect galaxies over a very wide range in redshift, making them powerful tools for studying the distant universe. Until recently, though, identifying the optical counterparts of faint radio sources and measuring…

Astrophysics · Physics 2007-05-23 Elaine M. Sadler , Carole A. Jackson , Russell D. Cannon

In this paper, we explore how the forthcoming generation of large-scale radio continuum surveys, with the inclusion of some degree of redshift information, can constrain cosmological parameters. By cross-matching these radio surveys with…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-20 Stefano Camera , Mário G. Santos , David J. Bacon , Matt J. Jarvis , Kim McAlpine , Ray P. Norris , Alvise Raccanelli , Huub Röttgering

Updates are provided on several issues related to Unified Models. A new HST spectrum of Cygnus A confirms the broad MgII emission line, and suggests a very large velocity width as seen in the polarized optical lines. Statistics of the 3CR…

Astrophysics · Physics 2007-05-23 Robert Antonucci

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

In this paper the next attempt is made to clarify the nature of the Euclidean behavior of the boundary in the angular size-redshift cosmological test. It is shown experimentally that this can be explained by the selection determined by…

Cosmology and Nongalactic Astrophysics · Physics 2015-01-13 V. R. Amirkhanyan

Radio galaxies provide a means to determine the coordinate distance,the luminosity distance, the dimensionless luminosity distance, or the angular size distance to sources with redshifts as large as two. Dimensionless coodinate distances…

Astrophysics · Physics 2020-05-13 Ruth A. Daly

The majority of this paper is devoted to discrete radio sources, and their consequences for cosmology. Three main issues are considered: (i) what makes a galaxy radio loud?; (ii) what do we know about how the population of radio-loud…

Astrophysics · Physics 2007-05-23 John Peacock
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