Laboratory formation of scaled astrophysical outflows

TL;DR

This study uses laboratory experiments and simulations to classify astrophysical outflows based on Mach numbers, providing a quantitative framework for understanding their diverse morphologies and conditions.

Contribution

It introduces a laboratory and simulation-based approach to categorize astrophysical outflows by their Mach numbers, linking morphology to physical parameters.

Findings

Outflow morphologies depend on external Alfvenic and sonic Mach numbers.

Transitions in outflow types occur at specific Mach number thresholds.

Results are consistent with magnetohydrodynamics simulations and observable in astronomy.

Abstract

Astrophysical systems exhibit a rich diversity of outflow morphologies, yet their mechanisms and existence conditions remain among the most persistent puzzles in the field. Here we present scaled laboratory experiments based on laser-driven plasma outflow into magnetized ambient gas, which mimic five basic astrophysical outflows regulated by interstellar medium, namely collimated jets, blocked jets, elliptical bubbles, as well as spherical winds and bubbles. Their morphologies and existence conditions are found to be uniquely determined by the external Alfvenic and sonic Mach numbers Me-a and Me-s, i.e. the relative strengths of the outflow ram pressure against the magnetic/thermal pressures in the interstellar medium, with transitions occurring at Me-a ~ 2 and 0.5, as well as Me-s ~ 1. These results are confirmed by magnetohydrodynamics simulations and should also be verifiable from existing and future astronomical observations. Our findings provide a quantitative framework for understanding astrophysical outflows.