Experimental and Numerical Studies of the Collapse of Dense Clouds Induced by Herbig-Haro Stellar Jets

TL;DR

This paper combines experimental and numerical methods to study how Herbig-Haro stellar jets can trigger star formation by compressing molecular clouds, showing that jets can significantly reduce cloud stability and induce collapse.

Contribution

It presents a novel high-energy-density experiment and simulations that mimic stellar jet interactions with molecular clouds, providing new insights into star formation mechanisms.

Findings

Jet impact can reduce the Bonnor-Ebert mass by about 9%.

Experimental results agree with radiation hydrodynamics simulations.

Jets can trigger collapse in marginally stable molecular clouds.

Abstract

This study investigates the influence of Herbig-Haro jets on initiating star formation in dense environments. When molecular clouds are nearing gravitational instability, the impact of a protostellar jet could provide the impetus needed to catalyze star formation. A high-energy-density experiment was carried out at the LULI2000 laser facility, where a supersonic jet generated by a nanosecond laser was used to compress a foam or plastic ball, mimicking the interaction of a Herbig-Haro jet with a molecular cloud. Simulations using the 3D radiation hydrodynamics code TROLL provided comprehensive data for analyzing ball compression and calculating jet characteristics. After applying scaling laws, similarities between stellar and experimental jets were explored. Diagnostic simulations-including density gradient, emission, and X-ray radiographies-showed strong agreement with experimental data. The results of the experiment, supported by simulations, demonstrate that the impact of a protostellar jet on a molecular cloud could reduce the Bonnor-Ebert mass by approximately 9%, thereby initiating collapse.