Momentum transfer by astrophysical jets

Abstract

view Abstract Citations (119) References (47) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Momentum Transfer by Astrophysical Jets Chernin, Lawrence ; Masson, Colin ; Gouveia dal Pino, Elisabete M. ; Benz, Willy Abstract We have used 3-D smoothed particle hydrodynamical simulations to study the basic properties of the outflow that is created by a protostellar jet in a dense molecular cloud. The dynamics of the jet/cloud interaction is strongly affected by the cooling in the shocked gas behind the bow shock at the head of the jet. We show that this cooling is very rapid, with the cooling distance of the gas much less than the jet radius. Thus, although ambient gas is initially driven away from the jet axis by the high thermal pressure odf the post-shock gas, rapid cooling reduces the pressure and the outflow subsequently evolves in a momentum-conserving snowplow fashion. The velocity of the ambient gas is high in the vicinity of the jet head, but decreases rapidly as more material is swept up. Thus, this type of outflow produces extremely high velocity clumps of post shock gas which resemble the features seen in outflows. We have investigated the transfer of momentum from the jet to the ambient medium as a function of the jet parameters. We show that a low Mach number (<6) jet slows down rapidly because it entrains ambient material along its sides. On the other hand, the beam of a high Mach number jet is separated from the ambient gas by a low density cocoon of post-shock gas, and this jet transfers momentum to the ambient medium principally at the bow-shock. In high Mach number jets, as those from young stellar objects, the dominant interaction is therefore at the bow shock at the head of the jet. Publication: The Astrophysical Journal Pub Date: May 1994 DOI: 10.1086/174055 arXiv: arXiv:astro-ph/9404032 Bibcode: 1994ApJ...426..204C Keywords: Hydrodynamics; Jet Flow; Molecular Clouds; Momentum Transfer; Numerical Analysis; Protostars; Shock Waves; Three Dimensional Models; Entrainment; Herbig-Haro Objects; Mach Number; Astrophysics; HYDRODYNAMICS; ISM: JETS AND OUTFLOWS; SHOCK WAVES; STARS: MASS LOSS; STARS: PRE--MAIN-SEQUENCE; Astrophysics E-Print: to appear in ApJ, May 1994, only abstract is posted to archive, e-mail chernin@ucbast.berkeley.edu to obtain complete paper, Plain TeX, 21 pages, 9 figures full text sources arXiv | ADS | data products SIMBAD (1)