The formation and evolution of star-forming filaments

CONTEXT. Filaments play a critical role in star formation. There are dense, massive filaments where a large fraction of low- and intermediate-mass stars form, and which also channel interstellar gas into even denser, more massive hubs where high-mass stars form; and there are more diffuse, lighter filaments which feed material onto the denser filaments. These filaments seem to possess a number of tell-tale properties, for example: (i) many of them appear to have a width of order 0.1 pc; (ii) the ambient magnetic field field seems to play an important role in determining their orientation; and (iii) star formation only starts once the surface-density exceeds ~ 200 M₈pc^-2. There is a growing body of detailed observational data on the morphology and magnetic-field structure of filaments, from the BISTRO project, and it is timely to try to explain this data theoretically.

PROJECT. This project will use numerical magneto-hydrodynamic simulations to explore filament formation and evolution, starting from dynamical initial conditions informed by galactic-scale simulations of the interstellar medium. It will aim to reproduce the configurations observed by BISTRO using POL-2 on the James Clerk Maxwell telescope, by developing statistical descriptors for the observed configurations. In the first instance we will use the PHANTOM Smoothed Particle Magneto-Hydrodynamics code, with additional modules to treat the thermal and chemical processes that regulate the dynamics. We will post-process the results using UCLChem, LIME and RadMC to produce line profiles, line maps and dust-continuum maps. We will also, if time allows, try to constrain the consequences of the filamentary environment for the statistical properties of the stars formed therein (mass function, mass segregation, clustering properties, multiplicity statistics).

SKILLS. The student will become expert in interstellar gas dynamics and modelling the associated chemical and radiative processes, triggered star formation, numerical hydrodynamics and radiation transport. Once acquired, these skills can be applied to a range of other problems in astrophysics, and many can also be applied in other fields like meteorology.

Eligibility

The typical academic requirement is a minimum of a 2:1 a relevant discipline.

Applicants whose first language is not English are normally expected to meet the minimum University requirements (e.g. 6.5 IELTS) (https://www.cardiff.ac.uk/study/international/english-language-requirements)

How to apply

Applicants should apply to the Doctor of Philosophy in Physics and Astronomy.

Applicants should submit an application for postgraduate study via the Cardiff University webpages (https://www.cardiff.ac.uk/study/postgraduate/research/programmes/programme/physics-and-astronomy) including:

• your academic CV

• a personal statement/covering letter

• two references, at least one of which should be academic

• Your degree certificates and transcripts to date (with certified translations if these are not in English).

In the "Research Proposal" section of your application, please specify the project title and supervisors of this project.

This project is only available to self-funded students, please can you include your funding source in the "Self-Funding" section.