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UK Astronomy Technology Centre

2021 PhD projects

Our scientists and staff have several PhD projects available via the University of Edinburgh's Institute for Astronomy (IfA) for admission in September 2021. Full details of the process are outlined at the IfA's studentships page. Further details of the offer projects are below.

MOONS: The next generation Multi-Object Optical and Near-infrared Spectrograph for the VLT

Oscar A. Gonzalez

MOONS is the new Multi-Object Optical and Near-infrared Spectrograph currently under construction for the Very Large Telescope (VLT) at ESO. This remarkable instrument combines, for the first time, the collecting power of an 8-m telescope, 1000 fibres with individual robotic positioners, and both low- and high-resolution simultaneous spectral coverage across the 0.64–1.8 μm wavelength range. This facility will provide the astronomical community with a powerful, world- leading instrument able to serve a wide range of Galactic, extragalactic and cosmological studies.

In this project the student will become part of the team at the UK Astronomy Technology Centre (UKATC) in the preparatory work for the successful exploitation of the forthcoming MOONS observations. The student will lead the analysis of simulations using the end-to-end simulator (VirtualMOONS) in order to fine-tune the Data Reduction Software functionality and performance, directly impacting the exploitation of future MOONS datasets. The student will also carry the analysis of ancillary spectroscopic datasets (FLAMES, KMOS, APOGEE, MUSE) as well as wide-field photometric surveys (VVVX, LSST, DECam) to develop dedicated science calibration programmes. Depending on the candidate’s interest, the student will join the technical team at UKATC during the Instrument Integration stage in the development of analysis software for testing, verification, and calibration of the instrument components throughout the commissioning stage.

CUBES: Bringing a unique capability to ESO's VLT

Chris Evans, Cyrielle Opitom & Colin Snodgrass

The four 8.2m telescopes of ESO’s Very Large Telescope (VLT) are the world’s most scientifically productive ground-based observatory at visible/infrared wavelengths. Looking to the future of the VLT there is a long-standing aspiration for an optimised ultraviolet (UV) spectrograph, culminating in plans for the Cassegrain U-Band Efficient Spectrograph (CUBES). With a science case strongly motivated by stellar astrophysics and nucleosynthesis, but also driven by compelling cases from extragalactic astronomy and Solar System science, CUBES will provide a world-leading capability to obtain high-resolution spectroscopy (R = 20,000) in the near ultraviolet (300 – 400 nm), with a tenfold sensitivity gain compared to existing instruments (e.g. ESO’s UVES instrument).

In this project you will become part of the team at the UK Astronomy Technology Centre (UKATC) in leading the development of the scientific case and preparing for early observations with CUBES, alongside work in the design and delivery of the detector system. Depending on the candidate's interests, there is scope to exploit observational programmes in support of future CUBES observations in massive stars (using data from an ongoing large X-Shooter programme in the Magellanic Clouds) or searches for OH emission in main-belt comets. The project will include careful modelling of the instrument performance as the project progresses, particularly with regard to the detector performance and chararacteristics to ensure that the scientific goals for the instrument are met.

Laser-fabricated optics for astronomy

Supervisors: Chris Evans, David Lee

As the scale and complexity of astronomical instruments grow, new technologies are being sought to satisfy the scientific requirements combined with feasible manufacturing. One of the most compelling emergent manufacturing technologies is Ultrafast Laser Inscription (ULI), where ultrashort laser pulses are used to modify the refractive index and/or chemical etch-rate of a substrate over very small scales. Important first steps have been taken in developing ULI-fabricated optics for astronomical applications, but their performance is not yet at the level required.

As part of a newly-approved joint project with Heriot-Watt University, this PhD is on the development and testing of ULI-fabricated optics in an astronomical context. This will involve possible applications in three key areas (image slicers, photonic spectrographs, micro-lens arrays), where ULI could have a disruptive impact on the performance and cost of future instruments. The project will include work on initial specifications of the components and testing of prototypes to validate their performance against the astronomical requirements for future capabilities on large ground-based telescopes (e.g. VLT, ELT).

Resolved Stellar Populations with ELT-HARMONI: setting the path from the VLT to the ELT

Oscar Gonzalez

The spectroscopic study of resolved stellar populations to determine the chemo-dynamical properties of galaxies and their components is fundamental to unravel the complex formation and evolution of galaxies from a very detailed perspective, which goes well beyond the determination of the mean chemical and kinematic properties. The study of evolved low-mass stars such as red giant branch (RGB) stars is of crucial importance: low-mass stars can have lifetimes longer than a Hubble time and act then as living fossils; Population II stars formed any time from the earliest star formation epochs to 1-1.5 Gyr ago are all expected to evolve as bright RGB stars.

Within the Milky Way (MW), the innermost regions have for very long remained inaccessible because of the large amounts of dust extinction. Near-IR spectroscopy with 8m-class telescopes has opened the possibility to partially access those regions. However, with more than 3 magnitudes of extinction even in K-band, the need for a 40m class telescope to reach low-mass RGB stars (K > 17.5) is unavoidable. Furthermore, the high stellar crowding of these regions requires high spatial resolution to resolve stars down to these faint magnitudes.

On the other hand, with current instrumentation on 8m-10m class telescopes, (low/intermediate resolution) spectroscopy of resolved RGB stars is possible within our own Local Group. While this hosts a very sizeable sample of dwarf galaxies of different types, it does not host any large elliptical and only a handful of small (M33 and the Large Magellanic Cloud) and large disc galaxies (the Milky Way & M31).

It will be with HARMONI, the first light instrument for the Extremely Large Telescope, that several hundreds of RGB stars will be finally accessible for systems within ~4 Mpc, including CenA, and for the nuclear bulge of the Milky Way (at high spectral resolution). This PhD project has the main objective of producing and analysing simulations of the future observations of resolved stellar populations for these cases. The student will learn the necessary skills and tools to do so by studying available IFU datasets of the Milky Way and other galaxies. Specifically, the student will:

The student will ultimately lead the Galactic Centre study at UKATC and will become an active collaborator of the local volume study in collaboration with IAC researchers (G. Battaglia).

Quantifying Photon Dominated Regions with ALMA & JWST

Pamela Klaassen

Information Video

Photodissociation Regions (or PDRs) are the interface between the hot, ionised gas surrounding a massive star and its cooler, molecular surroundings. The shock physics and chemistry in these PDRs are so dynamic that it’s hard to figure out where to start understanding them. PDR models are still quite primitive because we haven’t had access to high resolution observations (spatial *and* spectral) at the relevant wavelength ranges (IR to sub-mm) where the interesting shock chemistry happens (which traces the physics).

In this project, the student will apply for and then lead an ALMA project to quantify the PDR and molecular gas in the Horsehead nebula. This region has been chosen because the ALMA project can act as a good compliment to the JWST/MIRI Guaranteed time project observing the same target which the student will participate in.

The VLT-MOONS Galactic survey: towards a complete chemo-dynamical characterisation inner bulge and bar

Oscar Gonzalez

The understanding of galaxy formation and evolution is one of the fundamental goals of modern astronomical research. The Milky Way offers a one-of-a-kind opportunity to investigate the formation of a prototypical disc galaxy by looking at the individual ages, chemical abundances, and orbital movements of its stars. In recent years, we have witnessed remarkable progress towards characterising the stellar populations of the Milky Way thanks to large-scale spectroscopic surveys. However, the innermost regions of the Galaxy have remained mostly unreachable to them due to the very large amounts of dust obscuration. This presents a tremendous limitation, as simulations show us that the properties of the central, in-plane regions of disc galaxies hold unique fingerprints of the role that different processes such as dynamical instabilities, hierarchical merging, and dissipative collapse played across the history of the entire galaxy.

In this project, the student will join the leading team of the VLT-MOONS Galactic Survey. The student will work on the development of tools to derive radial velocities, stellar parameters and abundances for millions of stars to be observed with MOONS during its lifetime. The student will participate closely on the design and preparation of the survey, the analysis of commissioning data, science verification, and have a leading role in the analysis the first year of the GTO survey observations. A fraction of the time can be dedicated to the analysis of state-of-the-art simulations of bulge formation and VLT-MUSE observations of nearby bulges, in order to place the forthcoming MOONS results in a general context of bulge formation.

Hubble's legacy in the Magellanic Clouds

Chris Evans

With masses more than ten times that of the Sun, these stars burn very brightly for just a few million years before exploding violently as supernovae. During their lives they manufacture the materials from which planets and life are made and, via their high- energy winds and explosive deaths, they shape the chemistry and evolution of their host galaxies.

Only by learning how these stars behave in the local Universe can we attempt to interpret distant, star-forming galaxies, whose light is dominated by vast numbers of these spectacular objects, and which astronomers use to chart the history of the Universe from the Big Bang through to the present.

The Hubble Space Telescope is now taking observations for the unprecedented 1000-orbit ULLYSES program to build an ultraviolet spectroscopic library of massive stars while the telescope is still functioning. The targets build substantially on optical data from projects led in the past by Evans. This project will combine these existing data with new observations from an X-Shooter Large Programme and the new UV data from HST. Initial topics for study will be the UV morphological properties of the ULLYSES targest in the spectacular 30 Doradus star-forming region, quantitative analysis of the terminal velocities of their stellar winds, and seeking new insights into binary systems where the properties of the secondary have eluded us from optical spectroscopy alone.

Galaxy Archaeology with Asymptotic Giant Branch Stars

Annette Ferguson (IfA) and Olivia Jones (UK ATC)

Thermally-pulsing asymptotic giant branch (TP-AGB) stars are the descendants of low-to-intermediate mass (~1-8 solar masses) main-sequence stars. Their numbers reflect the star formation histories of galaxies over the last few billion years and their chemical properties constrain the metal enrichment of galaxies as well as their dust production rates.

Compared to other resolved stellar population tracers (e.g. main sequence stars, red giant branch stars), AGB stars offer some tremendous advantages -- their high luminosities at near and mid-IR wavelengths make them detectable out to ~10-20 Mpc distances while the fact that their spectral energy distributions peak at long wavelengths makes them much less susceptible to dust extinction.

We are about to enter a golden age for AGB studies in Local Volume galaxies. The launch of JWST in 2021, and Euclid in 2022, is expected to lead to many breakthroughs in our understanding of this enigmatic phase of stellar evolution and how we can use AGB populations to quantitatively constrain galaxy histories. We seek a PhD student to work with us one or more of the following projects: