Analyzing a sample of 57 radio galaxies from the 3CR catalogue, which were clearly resolved at 1.4 GHz or 5 GHz, Fanaroff & Riley (1974) discovered that the relative positions of regions of high and l
ow surface brightness in the lobes of extragalactic radio sources are correlated with their radio luminosity. They divided the sample into two classes using the ratio RFR of the distance between the regions of highest surface brightness on opposite sides of the central galaxy or quasar, to the total extent of the source up to the lowest brightness contour in the map. Fanaroff-Riley Class I (FR-I) , Fanaroff-Riley Class II (FR-II). The boundary between the two classes is not very sharp, and there is some overlap in the luminosities of sources classified as FR-I or FR-II on the basis of their structures. The physical cause of the FR-I/II dichotomy probably lies in the type of flow in the radio jets.
A pattern of smokestack plume dispersion in a statically stable atmosphere, in which the plume spreads out in the horizontal like an oriental fan and meanders about at a fixed height with little verti
cal spread.
An instrument consisting of an electrode fromwhich electrical current is measured while a charged particle beam(electrons or ions) impinges on it. Used to determine energy spectrum andsometimes ion co
mposition of the impinging particles.
An instrument consisting of an electrode from which electrical current is measured while a charged particle beam (electrons or ions) impinges on it. Used to determine energy spectrum and sometimes ion
composition of the impinging particles. (spase)
An instrument consisting of an electrode from which electrical current is measured while a charged particle beam (electrons or ions) impinges on it. Used to determine energy spectrum and sometimes ion
composition of the impinging particles. (spase)