| Description: | Deep observations of nearby galaxies give a lot of interesting science, but they also give pretty pictures. Today, Rense Boomsma will defend his PhD thesis (with the title "The disk-halo connection in NGC 6946 and NGC 253") in Groningen. In this thesis, the properties of the neutral hydrogen in the halos of galaxies is studied in great detail. One of the observations analysed in this thesis is an ultra-deep WSRT observation of the nearby spiral galaxy NGC 6946. These observations revealed many interesting features of the halo gas, but it also produced a very nice picture that has become one of the icons of the WSRT.
Note that the optical (left) and radio (right) image have the same scale. Thus, the halo of neutral hydrogen is much larger than the volume of stars that we can see with our eyes. The same is true for our own galaxy. |
