The Evolution of Hetergeneous "Clumpy Jets": A Parameter Study

TL;DR

This study explores how discrete clumps within astrophysical jets influence their shape and emission, revealing that clump interactions and velocity dispersion significantly affect jet stability and observable features.

Contribution

It extends previous work by analyzing the effects of clump parameters on jet morphology and emission, highlighting the impact of clump interactions and velocity dispersion.

Findings

Large velocity dispersion causes clump collisions that disrupt jets.

Synthetic emission images show excess [SII] emission compared to observations.

Minimal clump collisions yield better fit to observed jet features.

Abstract

We investigate the role discrete clumps embedded in an astrophysical jet play on the jet's morphology and line emission characteristics. By varying clumps' size, density, position, and velocity, we cover a range of parameter space motivated by observations of objects such as the Herbig Haro object HH~34. We here extend the results presented in Yirak et al. 2009, including how analysis of individual observations may lead to spurious sinusoidal variation whose parameters vary widely over time, owing chiefly to interacts between clumps. The goodness of the fits, while poor in all simulations, are best when clump-clump collisions are minimal. Our results indicate that a large velocity dispersion leads to a clump-clump collision-dominated flow which disrupts the jet beam. Finally, we present synthetic emission images of H-$\alpha$ and [SII] and note an excess of [SII] emission along the jet length as compared to observations. This suggests that observed beams undergo earlier processing, if they are present at all.