Open AccessHotspot position as an orientation indicator in FR II radio sources
Author(s) -
Gilbert G. M.,
Riley J. M.
Publication year - 1999
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.1999.02891.x
Subject(s) - physics , hotspot (geology) , radio galaxy , asymmetry , astrophysics , position (finance) , orientation (vector space) , galaxy , astronomy , geodesy , geometry , geophysics , geography , mathematics , finance , quantum mechanics , economics
We show that for a sample of radio sources with z <0.5 from the complete LRL data set the broad‐lined radio galaxies (BLRGs) have hotspots that are very much more recessed than their narrow‐lined counterparts. The asymmetry in the amount by which the hotspots are recessed in the two lobes of a source is also greater in the BLRGs. Assuming the standard unified model these results indicate that the position of the hotspots in the lobes is orientation‐dependent. The most plausible interpretation is that the hotspots do not always coincide with the termination point of the beam but are sometimes other, relativistically beamed, features internal to the lobes.