The contraction of molecular clouds towards the formation of stars is governed by an interplay between gravity, turbulence and magnetic fields. Determining which of these three forces dominates is at the centre of current star formation research. Gravity and turbulence are traditionally probed by observing star-forming clouds in optically thin tracers, providing both the mass of the cloud and its kinetic energy. Magnetic fields, on the other hand, are more difficult to measure. They require highly sensitive polarisation observations of the thermal dust emission. Such observations start to be available to the community as a result of the recent development of high sensitivity cameras such as SCUBA2-POL on the JCMT.
In a recent study, Peretto et al. (in prep) have characterised the ratio of kinetic to gravitational energy of sample of ~30 infrared dark clouds, and this from tenth to tens of parsec scale. In that study we found that molecular clouds are gravitationally bound on all scales, and that parsec-scale dense clumps of gas (those that typically form stellar clusters) are dynamically decoupled from their larger scale parent molecular cloud. Understanding what govern the evolution of these dense clumps is therefore fundamental to our understanding of star formation as a whole.
The goal of the PhD project is to jointly study the magnetic field properties and dense gas velocity of these clumps in order to determine whether they quasi-statically contract as a result of magnetic support, or if they quickly collapse, with no impact of the magnetic field on the future star formation yield.
In the context of this project, the student will analyse submillimetre JCMT SCUBA2-POL polarisation data, and IRAM 30m molecular line data of a subsample of infrared dark clouds. Most of the data has been obtained recently. The student will determine the most robust way to infer the magnetic field strength, and compare the magnetic field morphology with velocity gradients in order to determine the dynamical importance of B fields in the process of cloud evolution/ star formation. Follow-up observations at high angular resolution with the ALMA and NOEMA interferometers will be proposed early on during the PhD.
This project will be funded by the STFC.
Applicants should apply to the Doctor of Philosophy in Physics and Astronomy with a start date of 1st October 2020. https://www.cardiff.ac.uk/study/postgraduate/research/programmes/programme/physics-and-astronomy
In the research proposal section of your application, please specify the project title and supervisors of this project. If you are applying for more than one project, please list the individual titles of the projects in the text box provided. In the funding section, please select ’I will be applying for a scholarship/grant’ and specify that you are applying for advertised funding from the STFC.
Applicants will need to submit the following documents with their application:
- post high school certificates and transcripts to date
- academic CV
- personal statement
- two academic references. Your references can either be uploaded with your application, or emailed by the referee to [email protected]
or [email protected]
Tuition fee support: Full UK/EU tuition fees
Maintenance stipend: Doctoral stipend matching UK Research Council National Minimum
You should have obtained, or be about to obtain a First or Upper Second Class UK Honours degree in Physics , or a related subject, Alternatively, applicants with equivalent qualifications gained outside the UK will also be considered. Applicants with a Lower Second Class degree will be considered if they also have a Master’s degree.
Applicants whose first language is not English are normally expected to meet the minimum University requirements (e.g. 6.5 IELTS)