Very extended ionized gas in radio galaxies: Pt. 4

Optical, radio and ultraviolet observations of the luminous southern radio elliptical galaxy PKS2152-69 are presented. Narrow-band images and long-slit spectra reveal a system of low-ionization filaments extending out to a maximum radius of 20 arcsec (16 kpc; Ho=50 km s-1 Mpc-1 as used throughout this paper). To the north-east, however, a luminous cloud is found at a distance of 10 arcsec (8 kpc) from the nucleus. This emits lines of extremely high ionization, including [Ne v]λ3426, HeIIλ4686, [Ca v]λ5309, [Fe VII]λλ6087, 5721 and [Fe X]λ6374. In addition to the lines, the cloud has a continuum that is considerably bluer than that from the underlying stellar population. (author)