Undergraduate Research Programme

The Undergraduate Research Programme offers undergraduate students an invaluable opportunity to take part in cutting-edge research being undertaken in research centres at the University, such as the Centre for Astrophysics Research (CAR), which is a leading Astrophysics department in Europe. These projects are designed to give undergraduate students a taste of what working in frontier research is like and often contribute to journal publications. We welcome interest both from undergraduates who are current students at Hertfordshire and those who are not.

Students who are interested in working on a project should email the project supervisor as early as possible and copy in the research tutor (Sugata Kaviraj; s.kaviraj@herts.ac.uk). In their email, students should include a short statement (one or two paragraphs) explaining why they are interested in the project and attach a short CV. They are welcome to express interest in multiple projects (although they will typically work on one project, usually over the summer period). Supervisors will then set up an informal chat to discuss details of the projects with prospective students, after which students will be expected to make project selections. Some limited funding may be available and students will be advised of the details after they apply.

Unveiling the hidden Universe: using simulations and observational surveys to study ‘low-surface-brightness’ galaxies

Galaxy evolution studies to date have been dominated by bright objects that lie above the ‘surface brightness’ limit of past large surveys like the Sloan Digital Sky Survey (~23 mag/arcsec^2). However, state-of-the-art computer simulations and new observational surveys both indicate that ‘low-surface-brightness’ (LSB) galaxies i.e. ones that are fainter than the surface-brightness limits of past surveys actually dominate the galaxy number density in the Universe. Our current understanding of galaxy evolution is therefore highly incomplete, since it is based on a minority of the galaxy population. In other words, a complete comprehension of how the observable Universe evolves over time demands a detailed understanding of the LSB galaxy population.

In this project the student will use data from the new Hyper Suprime Cam (HSC) survey to study the properties of tens of thousands of galaxies in the low surface brightness regime, over at least the last 50% of the lifetime of the Universe. These observational results will then be compared to predictions from two state-of-the-art cosmological simulations, Horizon-AGN and New Horizon. The aim will be to (1) dissect the observed properties of LSB galaxies and (2) use the simulations to understand how these galaxies are likely to have formed, and their relationship to brighter galaxies on which our current understanding of galaxy evolution is predicated. This will be one of the first comprehensive investigations of the LSB Universe and the results of this project will form part of a journal article.

Appropriate for undergraduate students in their 2nd year and above 

Dates: 6-8 weeks (flexible) 

Supervisor details:

Sugata Kaviraj, s.kaviraj@herts.ac.uk, Room 2E66

Ryan Jackson, r.jackson9@herts.ac.uk, Room 2E68

Uncovering nearby hidden brown dwarfs with WISE

The list of the Sun's nearest neighbours has been growing for thousands of years, with brighter neighbours discovered further back in time. Alpha Centauri AB (G/K type) for instance was listed in the 2nd century star catalogue of Ptolemy, with the cooler fainter Barnard's star and Proxima Centauri discovered ~100 years ago. More recently, as new telescopes provide greater sensitivity and longer wavelength coverage, brown dwarf discoveries have jumped into the chart e.g. Luhman 16, WISE 0855-0714, and Epsilon Indi AB. Nearby systems are important astronomical targets for studies of stellar/substellar physics and exoplanet systems. And there is even a theory that the Sun may possess a previously unseen brown dwarf companion in a very wide orbit (Nemesis). Expectations remain that a significant populations of local stars and brown dwarfs are currently unknown. WISE is a space-based mid-infrared telescope launched in 2010, that has been imaging the sky on a 6-monthly basis providing multiple coverages (epochs) that offer the best sensitivity to the coolest nearby brown dwarfs. However, WISE has low spatial resolution, with sources being several arcseconds across. This leads to serious source-crowding in regions such as the galactic plane and centre, towards which nearby brown dwarfs could be hiding undiscovered. WISE's latest Spring data release will provide the largest number of epochs yet, and in this project you will use this multi-epoch data to hunt for nearby high proper motion brown dwarfs in crowded sky. You will utilize a range of methods to combine the multi-epoch data, and visually isolate the signatures of moving brown dwarfs from the crowded background. And you will also test your methods on known objects, to assess their effectiveness in different situations. New discoveries would be exciting objects, and be fast-tracked for observation using the group's large telescope programmes.

Appropriate for undergraduate students in any year

Dates: 4-12 weeks (flexible)

Supervisor details: David Pinfield, d.j.pinfield@herts.ac.uk, room 1e66

Does feedback from supermassive black holes influence the evolution of dwarf galaxies?

Energetic feedback from supermassive black holes, that reside in the centres of galaxies, is thought to strongly influence the evolution of their hosts over cosmic time e.g. by regulating the growth of stellar mass and sometimes inducing significant structural changes. The role of black holes has been comprehensively studied only in massive galaxies, largely because these are the objects that are readily detected in past observational surveys. However, dwarf (i.e. low-mass) galaxies are much more numerous than their massive counterparts and the role of black holes in these systems is one of the key open questions in modern astrophysics. It is not clear whether supermassive black holes actually exist in dwarfs in large numbers and, if they do, what their role is (if any) in influencing the evolution of these systems.

In this project, the student will use the state-of-the-art New Horizon simulation, to estimate the fraction of dwarf galaxies that host black holes, and explore the impact of these black holes on the evolution of their hosts. They will then compare these predictions to real data from the Hyper Suprime Cam survey to develop a picture of the role of black holes in the dwarf-galaxy regime. The results of this project will form part of a journal article.

Appropriate for undergraduate students in their 2nd year and above 

Dates: 6-8 weeks (flexible) 

Supervisor details:

Sugata Kaviraj, s.kaviraj@herts.ac.uk , Room 2E66

Ryan Jackson, r.jackson9@herts.ac.uk, Room 2E68

Galaxies with anomalous fractions of Dark Matter

Recent observational work has revealed the presence of galaxies that appear to have little or no dark matter (A galaxy lacking dark matter) , though the findings, and their implications, are still hotly debated. The aim of this project will be to use the state-of-the-art New Horizon cosmological simulation to find and analyse any galaxies that have either anomalously high or low dark matter fractions. The student will then identify what physical processes have caused these galaxies to have such anomalous dark matter fractions and whether there are any common features in their evolutionary history that create them. The results of this analysis can then be compared to observations to identify if there is any overlap, and if the findings can be reconciled with the simulation.

Appropriate for undergraduate students in their 2nd year and above 

Dates: 6-8 weeks (flexible) 

Supervisor details:

Ryan Jackson, r.jackson9@herts.ac.uk, Room 2E68

Sugata Kaviraj, s.kaviraj@herts.ac.uk , Room 2E66

Exoplanet and brown dwarf studies using Gaia wide binaries

Gaia is an ESA corner stone mission to measure the distances and motions of ~a billion stars, and is revolutionizing many fields of astronomy. The 2nd Gaia data release is now available, and represents the biggest advance that Gaia will provide. The Herts low-mass group is using Gaia to seek wide binary systems that form the basis for a number of studies: (i) Ultracool dwarf companions to Gaia stars have their properties calibrated by the primary, becoming "benchmark objects" that reveal ultracool atmosphere physics. (ii) Cool objects close to wide Gaia binaries are likely to have been ejected from orbit around one of the binary components, and the identification of such objects would reveal brown dwarfs and giant planets that were previously hidden as orbital companions. (iii) Wide binary stars have common age and composition, with stellar activity dependent on age. But exoplanets in close orbit may tidally interact with their host stars (increasing their activity), and they may also accrete onto their host star's atmosphere changing the composition. Wide binary stars whose components have different composition and activity levels could thus show the "smoking gun" for exoplanet interaction and accretion. In this project you will develop a tool for determining optimal spectral types and classifications for Gaia stars based on all the available data. You will then construct a sample of wide binary systems, i.e. pairs of Gaia stars with ~arcminute separation and a shared distance and proper-motion. As time allows, you will have the opportunity to study a subset of these binaries in the context of one of the group projects.

Appropriate for undergraduate students in any year

Dates: 4-12 weeks (flexible)

Supervisor details: David Pinfield, d.j.pinfield@herts.ac.uk, room 1e66

Phosphorescence

Phosphorescence is the emission of light from a material that has been excited by some energising process (often the absorption of UV light), where the emission occurs over timescales that are longer than the short (nanosecond) decay times of fluorescence. Phosphorescence may last for seconds, minutes or hours, depending on the material studied. The project involves studying the phosphorescent decay of novel phosphorescent materials in the PAM optics labs, and seeking to understand the origin of the phosphorescence through literature studies and the design of suitable experiments.

Appropriate for undergraduate students in their 2nd year and above, who are interested in laboratory physics, semiconductors, optics and atomic processes.

Dates: 4-12 weeks (flexible) until mid-August at the latest

Supervisor details: Sean Ryan, s.g.ryan@herts.ac.uk, room 1E52

Light scattering in tissue

Optical medical imaging techniques rely on the detection of light that is both absorbed and scattered by the material through which it passes. The project involves studying the way light is scattered in tissue, to explore opportunities to infer the properties of the medium based on the emergent signal. The work will be undertaken in the PAM optics labs.

Appropriate for undergraduate students in their 2nd year and above, who are interested in laboratory physics and optics.

Dates: 4-12 weeks (flexible) until mid-August at the latest

Supervisor details: Sean Ryan, s.g.ryan@herts.ac.uk, room 1E52