Astronomical Instrumentation PhD Projects
Research projects on offer in our Astronomical Instrumentation Group
Laser-fabricated optics for astronomy
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
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:
- Use VLT-MUSE observations of the Galactic Bulge and bulges of external galaxies to perform a chemodynamical study of the formation and evolution of the inner regions of galaxies. The student will use this part of the project to learn the details of IFU data extraction and analysis
- Use (adapting and improving when necessary) a set of tools to produce simulated HARMONI cubes and extract stellar spectra for different instrument configurations under different conditions to evaluate the performance of HARMONI for the above key ELT science cases
- Develop spectral analysis tools specifically tuned for ELT-HARMONI data, to derive kinematics and chemical abundance information, building on the ones used on VLT-MUSE.
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).
CUBES: Bringing a unique capability to ESO's VLT
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.
MOONS: The next generation Multi-Object Optical and Near-infrared Spectrograph for the VLT
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.
Under the Milky Way & Local Group PhD projects see also:
Quantifying Photon Dominated Regions with ALMA & JWST Pamela Klaassen
The VLT-MOONS Galactic survey: towards a complete chemo-dynamical characterisation inner bulge and bar Oscar A. Gonzalez
Hubble's legacy in the Magellanic Clouds Chris Evans