VLA data of the interacting galaxy, NGC 3432, display a radio continuum halo, with a maximum extent of 5.3 kpc in projection above the plane, containing considerable substructure and discrete radio continuum ``spurs''. The detection of high latitude emission, either in the form of extended diffuse layer (DIG) or in discrete features, is often assumed to independently confirm the correlation of disk-halo interactions and underlying star formation. However the possibly extra-planar optical features in our narrowband Hα CCD images, acquired at Observatoire Mont Megantic, contain a significant stellar component suggesting they are not gaseous debris resulting from a ``blow out'' by star formation activity in the disk but rather are tidal features. Although the inclination (79(deg) ) of NGC 3432 hinders our ability to detect a DIG halo surrounding this galaxy with these data, we can confirm that it has a lower star formation rate than the Milky Way. Hence it is an interesting counter-example to the notion that pervasive radio halos exist in galaxies with high star formation rates. We suggest that the interaction between NGC 3432 and UGC 5983, rather than disk-halo outflow in NGC 3432, is responsible for any extra-planar features as well as the extended radio continuum halo.
No takes yet. Share an insight, caveat, or question.
English et al. (1997) studied this question.