Volumetric imagery of the Herbig-Haro object M42–HH2 is presented, and the observations interpreted in terms of a Mach disc/bow shock model. Difficulties are encountered if all of the observed phenomena are considered in terms of a single Mach disc/bow shock, with inhomogeneity of the interstellar medium and viewing angle being only partially able to explain differences between observed and predicted phenomena. It is considered more likely that two separate Herbig-Haro objects have been detected.
This is a preview of a remote PDF: http://mnras.oxfordjournals.org/content/269/2/403.full.pdf
C. A. Clayton, J. Meaburn. Volumetric imagery of the Herbig-Haro object M42-HH2, Monthly Notices of the Royal Astronomical Society, 1994, 403-408, DOI: 10.1093/mnras/269.2.403