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相关论文: Superluminal apparent motions in distant radio sou…

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We use data from the Parkes Half-Jansky Flat-Spectrum (PHJFS) sample (Drinkwater et al. 1997) to constrain the cosmic evolution in the co-moving space density of radio sources in the top decade of the flat-spectrum radio luminosity function…

天体物理学 · 物理学 2009-10-31 Matt J. Jarvis , Steve Rawlings

We extend and apply a model-independent analysis method developed earlier by Daly & Djorgovski to new samples of supernova standard candles, radio galaxy and cluster standard rulers, and use it to constrain physical properties of the dark…

天体物理学 · 物理学 2009-11-13 Ruth A. Daly , S. G. Djorgovski , Kenneth A. Freeman , Matthew P. Mory , C. P. O'Dea , P. Kharb , S. Baum

Symmetric extragalactic radio sources exhibit a baffling array of features - the remarkable symmetry between the two lobes, the emission in the radio frequency range, well collimated jets, core regions emitting blue and ultraviolet light,…

天体物理学 · 物理学 2007-05-23 Manoj Thulasidas

Many of the powerful radio galaxies observed at high redshift are very small, presumably because they are very young. A simple model, which treats the radio source as a bubble expanding into a radially stratified medium, is capable of…

天体物理学 · 物理学 2007-05-23 Mitchell C. Begelman

A gravitational lens model of the radio quasar B1422+231 is presented which can account for the image arrangement and approximately for the relative magnifications. The locations of the principal lensing mass and a more distant secondary…

天体物理学 · 物理学 2015-06-24 David W. Hogg , R. D. Blandford

As the Universe expands, the redshift of distant sources changes with time. Here we discuss gravitational lensing phenomena that are consequence of the redshift drift between lensed source, gravitational lens, and observer. When the source…

宇宙学与河外天体物理 · 物理学 2022-06-01 Giovanni Covone , Mauro Sereno

The results from the Supernova Cosmology Project indicate a relation between cosmic distance and redshift that corresponds to an accelerating Universe, and, as a consequence, the presence of an energy component with negative pressure. This…

天体物理学 · 物理学 2007-05-23 Daniel Enstrom , Sverker Fredriksson , Johan Hansson

The combination of deep exposures and high resolution offered by telescopes in space allows the detection of lensing over a wide range of source redshifts and lens masses. As an example, we model a lens candidate found in the southern…

天体物理学 · 物理学 2007-05-23 Rennan Barkana , David Hogg , Abraham Loeb , Roger Blandford

It has always been considered a serious error to treat the cosmological redshift as a Doppler velocity effect rather than the result of space expansion. It is demonstrated here that in practical terms this is not the case, and that the…

综合物理 · 物理学 2007-05-23 Alasdair Macleod

It is difficult to identify the distant galaxies selected in existing submillimeter (submm)-wave surveys, because their positional accuracy is only several arcseconds. Currently, centimeter-wave VLA observations are required in order to…

天体物理学 · 物理学 2007-05-23 Andrew W. Blain

The Hubble law is extended to massive particles based on the de Broglie wavelength. Due to the expansion of the universe the wavelength of an unbound particle would increase according to its cosmological redshift. Based on the navigation…

广义相对论与量子宇宙学 · 物理学 2009-11-11 Firmin J. Oliveira

Fast (~1000 km/s) outflows of neutral gas (from 21-cm HI absorption) are detected in strong radio sources. The outflows occur, at least in some cases, at distances from the radio core that range between few hundred parsecs and kpc. These HI…

天体物理学 · 物理学 2007-05-23 Raffaella Morganti , Clive Tadhunter , Tom Oosterloo , Joanna Holt , Bjorn Emonts

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…

天体物理学 · 物理学 2016-01-27 Steve Rawlings , Katherine M. Blundell , Mark Lacy , Chris J. Willott , Stephen A. Eales

We present spectroscopic and eleven-band photometric redshifts for galaxies in the 100-uJy Subaru/XMM-Newton Deep Field radio source sample. We find good agreement between our redshift distribution and that predicted by the SKA Simulated…

The hypothesis that the speed of light decreases by nearly 2 cm per sec and per year is discussed within the frame of a simple phenomenological model. It is shown that this hypothesis can provide an alternative explanation for the…

天体物理学 · 物理学 2007-05-23 Yves-Henri Sanejouand

We have undertaken a survey for HI 21-cm absorption within the host galaxies of z ~ 1.2 - 1.5 radio sources, in the search of the cool neutral gas currently "missing" at z > 1. This deficit is believed to be due to the optical selection of…

宇宙学与河外天体物理 · 物理学 2015-06-12 S. J. Curran , M. T. Whiting , A. Tanna , E. M. Sadler , M. B. Pracy , R. Athreya

We present a simple mechanism which can mimic dark energy with an equation of state w < -1 as deduced from the supernova data. We imagine that the universe is accelerating under the control of a quintessence field, which is moving up a very…

天体物理学 · 物理学 2009-11-11 Csaba Csaki , Nemanja Kaloper , John Terning

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…

天体物理学 · 物理学 2009-11-10 J. C. Jackson

I derive and discuss a simple semi-analytical model of the evolution of powerful radio galaxies which is not based on assumptions of self-similar growth, but rather implements some insights about the dynamics and energetics of these systems…

高能天体物理现象 · 物理学 2018-02-21 M. J. Hardcastle

The description of the cosmological expansion and its possible local manifestations via treating the proper conformal transformations as a coordinate transformation from a comoving Lorentz reference frame to an uniformly accelerated one is…

广义相对论与量子宇宙学 · 物理学 2008-06-03 L. M. Tomilchik