The jet-cloud interaction in 3CR galaxies

C. FEINSTEIN, F. D. MACCHETTO, M. F. MONTERO AND G. HÄGELE

La Plata, Buenos Aires, Argentina

Congreso; XLVIII Reunión Anual De La Asociación Argentina de Astronomía; 2005

Facultad de Ciencias Astronómicas y Geofísicas de la Universidad Nacional de La Plata

From the HST/WFPC2 3CR Snapshot Survey, data taken with the filters F555W, F702W and narrow-ramp, a set of galaxies with noticeable extended structure were selected (e.g. 3C 79, 3C 135, 3C 234, etc). All of these objects show large regions of [O III] 5007Å emission (narrow ramp filter) and the broad-band filters data show similar structures indicating the presence of strong emission in several lines over these regions. The morphology observed seems to be related (e.g. same position angle, direct overlapping or similar shape) with the radio-jet. For some canditates with this properties GMOS/Gemini spectrosopy was taken. These data (both HST direct imaging and Gemini spectroscopy) can be tested with diagnostic diagrams and total UV photons budget to understand the source of energy that is ionizing the gas. This source of ionization was commonly believed to be the UV photons emitted by the powerful AGN, but several of these objects shows clearly that shocks produce by the radio jet are the main cause of the observed gas line emission.