Title:	Relativistic beaming effects in the spectra of cores and hotspots in radio galaxies and quasars
Authors:	Ishwara-Chandra, C.H. Saikia, D.J.
Keywords:	GALAXIES: ACTIVE GALAXIES: NUCLEI QUASARS: GENERAL RADIO CONTINUUM: GALAXIES
Issue Date:	Sep-2000
Publisher:	Blackwell Publishing for the Royal Astronomical Society
Citation:	Monthly Notices of the Royal Astronomical Society, 2000, Vol.317, p658-666.
Abstract:	We present the results of multiwavelength observations of cores and hotspots, at L, C, X and U bands with the Very Large Array, of a matched sample of radio galaxies and quasars selected from the Molonglo Reference Catalogue. We use these observations to determine the spectra of cores and hotspots, and test the unified scheme for radio galaxies and quasars. Radio cores have been detected at all wavelengths in all of the quasars in our sample, whereas only ~50per cent of the galaxies have cores detected in at least one of the wavelengths. The degree of core prominence in this sample is consistent with the unified scheme for radio galaxies and quasars. A comparison of the distributions of the two-point spectral index of the cores in our sample of lobe-dominated quasars, with the distributions in a matched sample of core-dominated quasars, shows that the distributions for these two classes are significantly different, and this is consistent with the expectations of the unified scheme. The difference in the spectral indices of the two hotspots on opposite sides is also significantly larger for quasars than for radio galaxies, as is expected in the unified scheme. We also investigate the relationship between the spectral index of the hotspots and the redshift or luminosity for our sample of sources.
Description:	Open Access
URI:	http://hdl.handle.net/2289/1590
ISSN:	0035-8711
Alternative Location:	http://adsabs.harvard.edu/cgi-bin/bib_query?2000MNRAS.317..658I http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2000MNRAS.317..658I&link_type=ARTICLE&db_key=AST http://arxiv.org/abs/astro-ph/0005392
Copyright:	(2000) Royal Astronomical Society
Appears in Collections:	Research Papers (A&A)

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