POSTGRADUATE STUDENTSHIP INFORMATION

PhD Research Projects


1. Spicules and Coronal Heating

Supervisor: Professor Gerry Doyle

The interplay between convection and the magnetic field near the Sun's surface leads to energisation of the outer solar atmosphere and inner heliosphere. One signature of this energy deposition is the presence of jets in the chromosphere, transition region, and corona. The most ubiquitous jets in the solar chromosphere are spicules which have the potential to play a major role in the mass and energy balance of the corona and solar wind. There is overwhelming evidence of different spicule types, which have been observed with a variety of diagnostics using imaging and spectroscopy. Magnetic waves of various types are observed in association with spicules which often undergo heating to at least transition region temperatures. We currently do not understand the mechanism(s) responsible for the formation and heating of these features, the role of the magnetic field in their dynamic evolution or their full impact on the mass and energy balance of the outer solar atmosphere. None of the multitude of theoretical models available is able to simultaneously explain the ubiquity, speeds, heating and dynamical evolution of spicules.

In order to provide proper constraints on theoretical models and settle many of the outstanding issues we need to know the magnetic field structure, flows and thermodynamic conditions in and around spicules. We wish to build on our detection of high frequency waves in chromospheric spicular features and to explore more deeply the linkage between intensity and horizontal velocity oscillations which could be due to coupling of compressive and non-compressive waves and the interaction of the flux tube with its neighbours. We seek a PhD student to use high-resolution observations from the Swedish Solar Telescope, the Daniel K. Inouye Solar Telescope and selected space-based facilities. The project will involve data collection (via the use of a range of facilities), data reduction (via the use of super-computers), data interpretation and modelling (via various models).

For further information email Gerry Doyle


2. The Southern Galactic Plane Molecular Gas Survey and the Life Cycle of the Interstellar Gas

Supervisor: Professor Michael Burton

Molecular clouds are the crucibles in which galactic evolution occurs. They are the sites where new stars are formed and the reservoirs where the products of stellar nucleosynthesis end up, a part of a galactic ecosystem that recycles the materials of our Galaxy, driven by energy flows arising, ultimately, from stars.

Armagh leads a new project to view the molecular gas of the southern Milky Way with a fidelity never seen before. Using the Mopra millimetre-wave telescope in Australia we are undertaking a new survey of the southern Galaxy which is yielding a spatial and spectral resolution that is a factor ten better than achieved before in such a panoramic survey. A new vista of the molecular medium of our Galaxy is being opened up for exploration.

This PhD project will involve the analysis and interpretation of this new data set. A variety of projects are possible.

The first involves the quantification of the amount of "dark" molecular gas in the Galaxy. This is molecular gas where the normal tracer for molecular clouds, carbon monoxide, is absent. This will be done by comparing the Mopra data set to that obtained by a second telescope that is located on the very driest place of our planet, the summit of the Antarctic plateau.

A second project will be to establish the ubiquity of filamentary structures in molecular clouds, whose formation is believed to be an essential pre-cursor state to the formation of stars. Candidate filaments have been identified by the Herschel infrared space telescope in their dust emission. The Mopra telescope will be able to determine whether these are kinematically coherent structures, and so reveal where the next clusters of stars will form.

A third project connects with the next generation gamma ray telescope, the Cherenkov Telescope Array, whose construction is just starting in Chile. There is a close connection between the distribution of molecular clouds in the Galaxy and the generation of the most energetic photons in nature, produced via unknown processes in "cosmic accelerators". This project will quantify the amount and distribution of the molecular gas in the Galactic plane, necessary to interpret the images that the new gamma ray telescope will obtain.

For further information, email Michael Burton


3. Discovering short period variable stars using the large scale surveys

Supervisor: Dr Gavin Ramsay

Armagh Observatory is involved in two large scale time variability projects. The OmegaWhite survey, co-led by Armagh Observatory, is being carried out using the VST in Chile. Its aim is to detect short period variable stars such as ultra compact and accreting binaries, pulsating stars and flare stars. Objects like these allow astronomers to better understand accretion physics; how supernova 1a explosions are generated; how stellar binary systems evolve over time; the interior of stars through asteroseismology and the physics of stellar flares. Currently we are ~2/3 of the way to meeting our goal of 400 square degrees of sky coverage with more observations planned in 2017. We will be announcing the details of our exciting discovery of a 44 minute binary system early in 2017. The Gravitational-wave Optical Transient Observer (GOTO) is a project which aims to detect the optical counterpart of gravitational wave events detected by the Advanced Ligo and Virgo detectors. Armagh Observatory is a consortium member of GOTO, which is sited on the island of La Palma in the Canaries - first light is expected in early 2017. Our strategy involves mapping the observable sky every few nights. The data is expected to provide a huge resource to search for variable stars of many different types including interacting binaries. A PhD project is available to work on the data obtained from both surveys and would suit someone interested in observational astronomy and ideally someone with experience of computing languages. It is expected there would opportunities for using international telescopes to make detailed observations of objects discovered in these surveys.

For further information contact Gavin Ramsay


4. The most massive stars in the early Universe

Supervisor: Dr Jorick Vink

In the massive star group, we work at the interface between theory and observation. Mass loss dominates the life and death of the most massive stars in the Universe. It determines the final mass and the type of explosion, as a supernova or a gamma-ray burst.

The project involves the modelling of massive stars, and comparing the differences in their mass loss and rotation between the First Stars (at zero metallicity) to those at Galactic metallicity Z.

Our models are compared to data from the VLT. We mostly focus on spectroscopic and polarization data from the LMC and the SMC, which, at metallicities between 1/5th and 1/2 Galactic Z, are the ideal testbeds to understand the difference between present-day massive stars and those in the early Universe.

By the end of the project, you will have acquired expertise in the modelling of mass loss and evolution, and confronted your models against observations from the largest telescopes (SALT, VLT) in the world.

Please do not hesitate to ask questions


5. Physical studies of asteroids with photometric and polarimetric techniques

Supervisor: Dr Stefano Bagnulo

We are carrying out an intensive observing campaign to acquire new photometric and polarimetric data for various objects of the solar system, from comets to asteroids, to giant planets. Observations involve the use of major facilities, e.g., the VLT and the WHT, but in particular the use of a polarimeter built at the Observatory of Torino (Italy), which is currently attached to a 1-m telescope located in the observing station of Calern, a facility of the Observatory of Nice (France), and of a polarimeter at the 2m telescope of the Rozhen Observatory in Bulgaria.

We are seeking a candidate to join an international collaboration, involving researchers from Italy, France, Belgium, Bulgaria and UK. After a training period requiring also a staying in Calern and in Rozhen, the PhD student will take care of a large part of the observations and of data reduction. In addition, the student will be involved in the scientific interpretation of the data, with particular emphasis on the derivation of some important physical properties of the asteroids. This project will require observational activities partly on site but mostly in remote mode, for typically a few weeks per year.

For further information contact Stefano Bagnulo


Last Revised: 2016 December 19th