2001A&A...380...40T

We have observed the Virgo cluster spiral 5 in X-rays with ROSAT (0.1-2.4keV) and in the optical. From the PSPC image one can distinguish different components, like the dominant source in the nuclear region, the galactic disk, and a diffuse soft component extended to the west. This latter one coincides with a giant Hα structure. In both spectral ranges the structure reaches up to 9 kpc out of the disk. This coincidence, the soft X-ray energy distribution, and the existence of a central starburst in 5 let us conclude that the X-ray gas traces a large scale outflow from accumulating supernova explosions and stellar winds in the galactic center. The resulting physical properties of this X-ray halo are comparable to those derived from X-ray halos in edge-on galaxies, like e.g. NGC 253. We also discuss the influence of the intracluster medium on the observed X-ray and Hα morphology. The spectral 0.1-2.4keV distribution of the central source and the X-ray-to-Hα luminosity ratio favour a supermassive star cluster at the very compact core rather than an accretion-powered active nucleus in agreement with the absence of a hard compact X-ray source in the ASCA band. The nearby Magellanic dwarf galaxy IC 3583 at a projected distance of only 30kpc reveals an unresolved X-ray point source, several blue knots in the optical, and a narrow Hα spur, pointing toward 5, detected also in the B band image. This is an indication for ongoing star formation also in IC 3583. Some interaction with 5 will be discussed although the relative radial velocity between both objects of about 1300km/s makes it rather unlikely.