Protostellar Outflow Evolution in Turbulent Environments - AstrophysicsReportar como inadecuado

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Abstract: The link between turbulence in star formatting environments and protostellarjets remains controversial. To explore issues of turbulence and fossil cavitiesdriven by young stellar outflows we present a series of numerical simulationstracking the evolution of transient protostellar jets driven into a turbulentmedium. Our simulations show both the effect of turbulence on outflowstructures and, conversely, the effect of outflows on the ambient turbulence.We demonstrate how turbulence will lead to strong modifications in jetmorphology. More importantly, we demonstrate that individual transient outflowshave the capacity to re-energize decaying turbulence. Our simulations support ascenario in which the directed energy-momentum associated with cavities israndomized as the cavities are disrupted by dynamical instabilities seeded bythe ambient turbulence. Consideration of the energy power spectra of thesimulations reveals that the disruption of the cavities powers an energycascade consistent with Burgers-type turbulence and produces a drivingscale-length associated with the cavity propagation length. We conclude thatfossil cavities interacting either with a turbulent medium or with othercavities have the capacity to sustain or create turbulent flows in star formingenvironments. In the last section we contrast our work and its conclusions withprevious studies which claim that jets can not be the source of turbulence.

Autor: Andrew J. Cunningham, Adam Frank, Jonathan Carroll, Eric G. Blackman, Alice C. Quillen


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