Signed, "A Black Hole" . ... Credit Copyright: B. Woodgate ( GSFC ), G. Bower( NOAO ), STIS Instrument Definition Team, NASA Explanation: This artistic image is actually the signature of a supermassive black hole in the center of distant galaxy M84 - based on data recently recorded by Hubble's new Space Telescope Imaging Spectrograph ( STIS ). ... These extreme velocity increases provide a "signature" of the black hole's presence. ... Do all galaxies have central black holes? ...