Far‐Ultraviolet and X‐Ray Observations of VV 114: Feedback in a Local Analog to Lyman Break Galaxies

We have analyzed FUSE, XMM, and Chandra observations of VV 114, a localgalaxy merger with strong similarities to typical high-redshift Lyman BreakGalaxies (LBGs). Diffuse thermal X-ray emission encompassing VV114 has beenobserved by Chandra and XMM. This region of hot (kT~0.59 keV) gas has anenhanced alpha to iron element ratio relative to solar abundances and followsthe same relation as typical starbursts between its properties (luminosity,size, and temperature) and those of the starburst galaxy (star formation rate,dust temperature, galaxy mass). These results are consistent with the X-ray gashaving been produced by shocks driven by a galactic superwind. The FUSEobservations of VV 114 show strong, broad interstellar absorption lines with apronounced blueshifted component(similar to what is seen in LBGs). This impliesan outflow of material moving at 300-400 km/s relative to VV 114. Theproperties of the strong OVI absorption line are consistent with radiativecooling at the interface between the hot outrushing gas seen in X-rays and thecooler material seen in the other outflowing ions in the FUSE data. We showthat the wind in VV114 has not created a ``tunnel'' that enables more than asmall fraction (< few percent) of the ionizing photons from VV114 to escapeinto the IGM. Taken together, these data provide a more complete physical basisfor understanding the outflows that seem to be generic in LBGs. This will leadto improved insight into the role that such outflows play in the evolution ofgalaxies and the inter-galactic medium.Comment: 33 pages, 13 figure