The Extended Blue Continuum and Line Emission around the Central Radio Galaxy in Abell 2597

We present results from detailed imaging of the centrally dominant radioelliptical galaxy in the cooling flow cluster Abell 2597, using data obtainedwith the Wide Field and Planetary Camera 2 (WFPC2) on the Hubble SpaceTelescope (HST). This object is one of the archetypal "blue-lobed" cooling flowradio elliptical galaxies, also displaying a luminous emission-line nebula, acompact radio source, and a significant dust lane and evidence of molecular gasin its center. We show that the radio source is surrounded by a complex networkof emission-line filaments, some of which display a close spatial associationwith the outer boundary of the radio lobes. We present a detailed analysis ofthe physical properties of ionized and neutral gas associated with the radiolobes, and show that their properties are strongly suggestive of directinteractions between the radio plasma and ambient gas. We resolve the bluecontinuum emission into a series of knots and clumps, and present evidence thatthese are most likely due to regions of recent star formation. We investigateseveral possible triggering mechanisms for the star formation, including directinteractions with the radio source, filaments condensing from the cooling flow,or the result of an interaction with a gas-rich galaxy, which may also havebeen responsible for fueling the active nucleus. We propose that the propertiesof the source are plausibly explained in terms of accretion of gas by the cDduring an interaction with a gas-rich galaxy, which combined with the fact thatthis object is located at the center of a dense, high-pressure ICM can accountfor the high rates of star formation and the strong confinement of the radiosource.Comment: Astrophysical Journal, in press, 34 pages, includes 6 PostScript figures. Latex format, uses aaspp4.sty and epsf.sty file