Bibcode
Prieto, M. A.; Walsh, J. R.; Fosbury, R. A. E.; di Serego Alighieri, S.
Bibliographical reference
Monthly Notices of the Royal Astronomical Society (ISSN 0035-8711), vol. 263, no. 1, p. 10-24.
Advertised on:
7
1993
Citations
25
Refereed citations
24
Description
3C 227 (z = 0.085) exhibits one of the more spectacular extended
nebulosities to be found among active galaxies at moderate redshifts.
The gas can be traced to radial distances of about 100 kpc. The total
forbidden O III 5007 A luminosity is 2.7 x 10 exp 42 erg/s, of which at
least 50 percent is radiated from the extended region rather than from
the immediate nuclear environment. Photoionization by continuum
radiation from an AGN is indicated by both the emission line ratios and
the variation of the ionization parameter with radial distance from the
nucleus. Extrapolation of the EUV of the observed nuclear continuum does
not explain the ionization state of the gas, and so it is necessary to
hypothesize an anisotropic nuclear radiation field. The kinematic
behavior of the gas is reasonably well ordered with a general apparent
rotation, but there is evidence for local distortions associated with
variations in surface brightness and with the radio axis. We have
modelled the velocity field with a filled biconical structure having an
axis tilted 40 deg from the plane of the sky. We conclude that 3C 227
could be a radio-loud, lobe-dominated quasar viewed in a direction close
to the edge of this radiation cone.