An Investigation of the Hydrodynamics of Hypersonic Jets in Astrophysical Conditions

Hypersonic, collimated jets are being lately intensively studied in Earth laboratories, trying to reproduce some of the physical properties of a subclass of astrophysical jets that are the Herbig-Haro (HH) jets. These jets are produced in the regions around Young Stellar Objects (YSOs), that are proto-stars located inside galactic Giant Molecular Clouds. In addition to the novel experimental approach, HH or YSO jets have been object of interest by the astrophysical community since a few decades and studied by means of observations at different wavelengths and analytical and numerical modeling. We present laboratory experiments and 2D numerical simulations of hypersonic jets, comparing the results of experiments and simulations that reproduce the evolution of the above mentioned jets. The experimental flows match two main scaling parameter requirements for proto-stellar jets, i.e. the ejection Mach number M and the jet/ambient density ratio. In particular, eta goes from slightly underdense to overdense values. Furthermore, as a development of previous works, we consider here the dependence of the jet structure and morphology on the Mach number, in the range 10 to 15.