|
| | | | |
| | | |
| Stat |
Members: 3645
Articles: 2'501'711
Articles rated: 2609
20 April 2024 |
|
| | | | |
|
Article overview
| |
|
|
The Australia Telescope 20 GHz (AT20G) Survey: The Bright Source Sample | | Marcella Massardi
; Ronald D. Ekers
; Tara Murphy
; Roberto Ricci
; Elaine M. Sadler
; Sarah Burke
; Gianfranco De Zotti
; Philip G. Edwards
; Paul J. Hancock
; Carole A. Jackson
; Michael J. Kesteven
; Elizabeth Mahony
; Christopher J. Phillips
; Lister Staveley--Smith
; Ravi Subrahmanyan
; Mark A. Walker
; Warwick E. Wilson
; | | Date: |
21 Sep 2007 | | Abstract: | The Australia Telescope 20 GHz (AT20G) Survey is a blind survey of the whole
Southern sky at 20 GHz (with follow-up observations at 4.8 and 8.6 GHz) carried
out with the Australia Telescope Compact Array (ATCA) from 2004 to 2007. The
Bright Source Sample (BSS) is a complete flux-limited subsample of the AT20G
Survey catalogue comprising 320 extragalactic (|b|>1.5 deg) radio sources south
of dec = -15 deg with S(20 GHz) > 0.50 Jy. Of these, 218 have near simultaneous
observations at 8 and 5 GHz. In this paper we present an analysis of radio
spectral properties in total intensity and polarisation, size, optical
identifications and redshift distribution of the BSS sources. The analysis of
the spectral behaviour shows spectral curvature in most sources with spectral
steepening that increases at higher frequencies (the median spectral index
alpha, assuming Spropto
u^alpha, decreases from alpha_{4.8}^{8.6}=0.11
between 4.8 and 8.6 GHz to alpha_{8.6}^{20}=-0.16 between 8.6 and 20 GHz),
even if the sample is dominated by flat spectra sources (85 per cent of the
sample has alpha_{8.6}^{20}>-0.5). The almost simultaneous spectra in total
intensity and polarisation allowed us a comparison of the polarised and total
intensity spectra: polarised fraction slightly increases with frequency, but
the shapes of the spectra have little correlation. Optical identifications
provided an estimation of redshift for 187 sources with a median value of 1.20
and 0.13 respectively for QSO and galaxies. | | Source: | arXiv, 0709.3485 | | Services: | Forum | Review | PDF | Favorites | |
|
|
No review found.
Did you like this article?
Note: answers to reviews or questions about the article must be posted in the forum section.
Authors are not allowed to review their own article. They can use the forum section.
browser Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; ClaudeBot/1.0; +claudebot@anthropic.com)
|
| |
|
|
|
|
News, job offers and information for researchers and scientists:
| |
REGISTER