Supernova-driven outflows in NGC 7552: a comparison of H α and UV tracers

摘要: We investigate the supernova-driven galactic wind of barred spiral galaxy NGC 7552, using both ground-based optical nebular emission lines and far-ultraviolet absorption measured with Hubble Space Telescope Cosmic Origins Spectrograph. detect broad (~300 km/s) blueshifted (-40 associated galaxy's kpc-scale star-forming ring. The line kinematics diagnostic ratios suggest that H-alpha comes from clouds high density gas entrained in a turbulent outflow. compare profile to UV along coincident sight find significant differences. maximum blueshift H-alpha-emitting is ~290 km/s, whereas extends blueshifts upwards 1000 km/s. mass outflow rate estimated roughly nine times greater than H-alpha. argue traces cluster-scale dense, low velocity at base large-scale wind. measurements are therefore more reliable tracers warm starburst-driven outflows.