Turbulence and molecular clouds in the Andromeda galaxy

📖 Project Description

The nature of turbulence in molecular clouds is one of the driving factors that influence the efficiency by which the gas is converted to stars. In the Milky Way, it is speculated that the high star formation efficiency observed in spiral-arm clouds is linked to the prevalence of compressive curl-free) turbulent modes in the motion of molecular gas, while the shear-driven solenoidal (divergence-free) modes appear to be the main cause of the low star formation efficiency that characterizes clouds in the Central Molecular Zone. We proved the inverse proportionality between the solenoidal modes of turbulence and the star formation efficiency in galactic-plane molecular clouds in the CHIMPS survey (https://ui.adsabs.harvard.edu/abs/2016MNRAS.456.2885R/abstract) and, in addition, that the solenoidal modes decrease with a shallow gradient with the distance from the center of the Galaxy. This shallow gradient is unaffected by the presence of spiral arms. Turbulence modes also vary locally and at different scales within a cloud: turbulent motions surrounding the main star-forming regions display a strongly compressive nature.

In this project, we extend this analysis, probing the relation between the modes of turbulence modes and galactic environments in the Andromeda galaxy (M31). Using the HARP and SCUBA-2 High- Resolution Terahertz Andromeda Galaxy Survey (HASHTAG, https://www.eaobservatory.org/jcmt/science/large-programs/hashtag/), we will have access to the CO emission in selected regions of M33, that are expected to cover a substantial sample (>1000) of sources with masses >103 solar masses at a resolution of 25 pc.

This summer project aims to investigate the environments of SLSNe by analysing deep imaging data from the DESI Legacy Survey and Subaru HSC. The goal is to identify whether SLSNe host galaxies have neighbouring companions and compare these findings with other transient host populations, such as: