Large optical filaments of the galaxy NGC4945

In order to observationally establish the phenomenon of mass loss from galaxies we have examined an optical image of a southern spiral galaxy, NGC4945, the strongest radiator of far-infrared emission in nearby galaxies. Radial filaments emerging from its nuclear region have been found in the northwestern side of the galaxy. The filaments extend 2 kpc towards the halo and 10 kpc along the galactic disk, respectively. The appearance of the filaments strongly suggests that ionized gas is flowing out from the nuclear region. The origin of the gas ejection could be attributed to supernova explosions and stellar winds due to active star formation, or to Seyfert activity. (author)