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: http://www.stsci.edu/science/preprints/prep1366/prep1366.html
Дата изменения: Mon Oct 16 22:01:22 2000 Дата индексирования: Sat Dec 22 15:21:58 2007 Кодировка: Поисковые слова: comet |
ST ScI Preprint #1366
Based on observations made with the NASA/ESA Hubble Space Telescope, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555
We present results of HST observations of the radio galaxy 3C 299. The broad-band F702W (R) and F555W (V) images (WFPC2/PC) show an elliptical galaxy, with a comet-like structure extending to the NE in the radio jet direction. The [OIII] 5007 emission line map, shows a bi-conical structure centered on the nucleus, that overlaps the structure found in the broad-band filters. The radio core coincides with the center of the bi-conical structure and the radio axes are aligned with the direction of the cones. These data show clear evidence of a strong interaction between the radio jet and the NE morphology of the galaxy. We show evidence that this NE region is an ENLR; the line-ratio diagnostics show that models involving gas shocked by the radio-jet plus ionization from a precursor HII region, produced itself by the ionizing photons of the postshocked gas on the preshocked gas provide a good match to the observations. We investigate the spatial behavior of the ionizing parameter U, by determining the [OIII]/[OII] line ratio which is sensitive to the change of the ionization parameter, and trace its behavior over the ENLR along the radio jet direction. We find that [OIII]/[OII] does not follow a simple dilution model, but rather that it is approximately constant over a large range of distance from the nucleus thus requiring a local source of ionization which seems to be compatible with the shock models driven by the radio jet.