Depolarization asymmetry in the quasar 3C 47

Fanaroff-Riley II Radio Galaxies and Quasars: The Depolarization Test

“…It should be noted here that high values of DP mean less depolarization. The method applied for the computation of DP is similar to that of , Fernini et al (1991), and Paper II. Figure 1 shows a plot of the ratio DP versus redshift z for the 19 sources.…”

“…In Fernini et al (1991), a simple model was developed to explain the strong depolarization asymmetry seen in the quasar 3C 47. The uniformity of the depolarization ratio in each lobe of 3C 47 led us to infer that the medium responsible for the depolarization is external, with a constant density n and magnetic Ðeld B through a length dl along the line of sight.…”

“…The depolarization asymmetry arises because of the di †erence in the path lengths to the two components of the source. An analytical expression for the depolarization ratio DPR, as deÐned by equation (2), was shown to be (Fernini et al 1991), where k is a constant, and are 20 j 2 j 1 and 6 cm, respectively, d is the cell size, D is the distance from the core to the lobe, h is the viewing angle, and is I 2 (h) the following trigonometric expression :…”

“…Our main problem is that several unknown parameters, such B, a, d, and D, are present in equation n 0 , (3). A physically reasonable combination of these parameters will be chosen in light of our results for 3C 47 (Fernini et al 1991). In the Ðrst approach, Ðxed values for the core FERNINI Vol.…”

“…The scale size d, in light of the resolution of our maps as described above, will initially be set equal to an upper limit of 1@ (D4 kpc), as in Fernini et al (1991). This is to produce Faraday depth Ñuctuations on scales small compared with the beamwidth.…”