Modelling low-mass star-forming galaxies

Student: Sakircan Beyazit
Supervisors: Ivan Baldry, Andreea Font (LJMU)
Institution: Liverpool John Moores University 

The MAGIS and AION collaborations are developing ultra-sensitive atom interferometers that will be used to search for ultra-light dark matter and detect gravitational waves. These detectors will be built and installed at Fermilab (US) and in the UK. Both collaborations are working towards a 100 metre baseline detector as a step towards a 1 km version with sufficient sensitivity to detect gravitational waves in the mid-band from 0.1 Hz - 10 Hz - between the Advanced LIGO and LISA experiments. The AION program was funded in 2021 via the STFC's Quantum Technology for Fundamental Physics call and builds upon strong links between the two collaborations. 

This studentship will focus on developing the readout of the detection system for AION and MAGIS. In addition, it will develop advanced fluorescence imaging techniques that allow single-shot imaging of ultracold atoms. The system will employ an in-vacuum piezo-driven retro reflection platform combined with low-noise cameras and a custom readout chain. This will be deployed at Fermilab in 2023 and is also being developed for AION. 

The work will take place in a sandwich format, with a secondment to the Rutherford Appleton Laboratory and frequent visits to Fermilab to ensure full integration of the student into the relevant engineering teams and non-academic partners. In addition, it will leverage the experience of RAL Space to determine the feasibility for future space flight missions using atom interferometry. 

Throughout the project you will have access to the Universities’ comprehensive postgraduate training in particle physics, as well as to targeted training in data science provided by the University of Liverpool with the Centre for Doctoral Training LIV.INNO. You will also be given the opportunity to carry out an industry placement of at least six months at RAL-Space to broaden your wider research and career skills. 

This project will be carried out over 48 months. You will spend years 1 and 4 in the UK, and be based at a combination RAL-Space, Fermilab and Liverpool during years 2 and 3. Whilst in the UK, a standard RKUK PhD stipend will be paid, during the time at Fermilab, the usual Fermilab doctoral student allowance will be paid. A mandatory 6-months industry placement forms part of the project. 

We can analyse galaxies individually or as a population. Focusing on the latter allows us to empirically track galaxy evolution since, if we measure demographics of galaxy populations at different distances, we are viewing the universe at different epochs. Measurements of galaxy populations can also be compared with cosmological-scale simulations to test the validity of the standard cosmological model. Galaxy demographics are key for empirically describing and understanding the processes of galaxy formation and evolution and can also play a role in constraining the nature of dark matter or dark energy. 

One key demographic measurement is the “galaxy stellar mass function” (GSMF), which generally depends on the properties of the environment that the galaxies inhabit (e.g., whether galaxies live in the field, in galaxy groups or in clusters).  In particular, the stellar mass function of low mass (“dwarf”) galaxies places an important constraint on cosmological models. Detecting and characterizing the low-mass galaxy population is currently at the frontier of astrophysics research.  

However, the observational measurements of the GSMF at the low mass end are particularly challenging because of the typical low surface brightness (SB) of dwarf galaxies. In this project, two new approaches are proposed to pin down the distribution of dwarf galaxies: 1) using multi-band deep imaging as input to a new spectroscopic survey (4MOST), and 2) a novel selection via core-collapse supernovae (SNe) (LSST) as ‘signposts’ to star-forming galaxies.  

The primary aims of this project are: to obtain definitive measurements of the galaxy stellar mass function (GSMF) to the lowest possible masses, and determine the star-formation rate density (SFRD) as a function of galaxy mass. Additionally, the GSMF measured from observations will be compared with predictions of state-of-the-art cosmological hydrodynamical simulations (developed in collaboration with the Virgo Consortium). This approach will test the physics of galaxy formation and evolution in a totally new regime and it will help us constrain the nature of dark matter. 

As part of this project, you will have the opportunity to join three major international surveys, which the Lead Supervisor is part of: WAVES, which is a large spectroscopic survey of 1.6 million galaxies planned to be carried out as part of the 4MOST Consortium; an Euclid Independent Legacy Science project; and will have access to LSST data via LSST:UK participation group in the large collaboration.

Throughout the project you will have access to the Astrophysics Research Institute’s postgraduate training programme, as well as to targeted training in data science provided by the Centre for Doctoral Training LIV.INNO. You will also be given the opportunity to carry out an industry placement of six months to broaden your wider research and career skills. You will also have priority access to high-performance computing resources at Liverpool John Moores University for your research.  

This project will be carried out over 48 months and is fully funded (tuition fees + stipend set by UKRI guidelines + a research/training budget), inclusive of the 6-month industry placement.  

Lead supervisors: Prof. Ivan Baldry (i.baldry@ljmu.ac.uk) , Dr. Andreea Font (a.s.font@ljmu.ac.uk)