Astronomy and Astrophysics – Astrophysics
Scientific paper
2008-10-21
Mon.Not.Roy.Astron.Soc.390:L1,2008
Astronomy and Astrophysics
Astrophysics
5 pages, 3 figures
Scientific paper
10.1111/j.1745-3933.2008.00509.x
The Caltech-Jodrell Bank very long baseline interferometry (VLBI) Surveys give detailed 5 GHz VLBI images of several hundred milliarcsecond (mas) radio sources, and the full width at half-maximum angular sizes of the corresponding compact cores. Using the latter, I have constructed an angular-diameter/redshift diagram comprising 271 objects, which shows clearly the expected features of such a diagram, without redshift binning. Cosmological parameters are derived which are compatible with existing concensus values, particularly when the VLBI data are combined with recent Baryon Accoustic Oscillations observations; the figures are presented as indications of what might be expected of larger samples of similar data. The importance of beaming and relativistic motion towards the observer is stressed; a model of the latter indicates that the emitting material is close to the observer's line of sight and moving with a velocity which brings it close to the observer's rest frame. With respect to linear size, these objects compare well in variance with type Ia supernovae; the efficacy of the latter is improved by the brighter-slower and brighter-bluer correlations, and by the inverse-square law.
No associations
LandOfFree
Is there a standard measuring rod in the Universe? does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Is there a standard measuring rod in the Universe?, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Is there a standard measuring rod in the Universe? will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-416143