EMPIRICAL DETERMINATIONS OF KEY PHYSICAL PARAMETERS RELATED TO CLASSICAL DOUBLE RADIO SOURCES

Multifrequency radio observations of the radio bridge of a powerful classical double radio source can be used to determine the beam power of the jets emanating from the active galactic nucleus (AGN), the total time the source will actively produce jets that power large-scale radio emission, the thermal pres-sure of the medium in the vicinity of the radio source, and the total mass, including dark matter, of the galaxy or cluster of galaxies traced by the ambient gas that surrounds the radio source. The theoretical constructs that allow a determination of each of these quantities using radio observations are presented and discussed. Empirical determinations of each of these quantities are obtained and analyzed for 22 radio sources; Cygnus A is one of the sources in the sample, but it is not used, or needed, to normalize any of these quantities. A sample of 14 radio galaxies and eight radio-loud quasars with redshifts between 0 and 2 was studied in detail; each source has enough radio information to be able to determine each of the physical param-eters listed above. The beam power was determined for each beam of each AGN (so there are two numbers for each source) ; these AGNs are highly symmetric in terms of beam powers. Typical beam powers are about 1045 ergs s~1. No strong correlation is seen between the beam power and the coreÈho