Astronomy with the Square Kilometre Array

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Astronomy and Astrophysics Group Research
Opportunities

• The distribution and evolution of dark matter
  halos and galaxies
• Supervisors Dr M A Hendry, Dr L F A Teodoro
• The key challenge for modern cosmology is
  understanding the process of galaxy formation
  the evolutionary transition from an almost
  perfectly smooth CMBR to the complex patterns of
  galaxy clustering that we observe today. Our
  research at Glasgow involves several different,
  although closely related, topics within this
  exciting and challenging field, and there are
  excellent PhD project opportunities in each of
  these topics
• investigating new statistical tools for
  describing the distribution of dark matter halos
  in 'state of the art' computer simulations of
  large scale structure formation.
• designing new 'mock' galaxy catalogues,
  mimicking current (e.g. 6dF) and proposed future
  (e.g. SKA) galaxy surveys, using semi-analytical
  methods to 'populate' dark matter halos with
  galaxies.
• developing a new, wave-mechanical, approach to
  simulations of large scale structure, exploiting
  important parallels between the classical
  equations of cosmic structure formation and the
  Schrodinger equation of quantum mechanics.
• For more details, see handout.

• Empirical studies of magnetic connectivity using
  UV Emission in Solar Flares
• Supervisor Dr L Fletcher
• Solar flares are abrupt and transient
  brightenings in the solar atmosphere, resulting
  from the release of a colossal amount of energy
  which was previously stored in the solar magnetic
  field. Many questions in flare physics centre
  around the storage and release of this energy,
  and address topics such as magnetic field
  structures in the corona, energy conversion and
  particle acceleration, and production of
  radiation.
• The main aims of the project will be
• to develop an efficient method for tracking and
  correlating compact UV features in the solar
  atmosphere
• to apply this to a number of different flare
  datasets to learn about the magnetic structures
  from which the energy is being released
• to compare the empirical results with theoretical
  models.
• The project will thus include computational work,
  observational analysis and theoretical modelling
  of magnetic fields. It is well-suited to
  candidates with and interest in the Sun, and a
  background in Physics and Astronomy, or
  Physics/Astronomy and Maths.
• For more details, see handout.

• Cosmic Magnetism and Plasma Cosmology
• Supervisors Dr D A Diver, Dr L F A Teodoro, Dr M
  A Hendry
• The role of the magnetic field in medium scale
  cosmic evolution is not well understood, given
  the complexity of the possible interactions.
• We aim to focus on two specific areas (1) the
  natural evolution of jets and other linear
  structures, and (2) the development of density
  structure in large-scale mixed flows of plasma
  and neutrals.
• Self-guiding magnetic fields, produced by Inverse
  Faraday Rotation( in which the internal plasma
  currents create an axial magnetic field component
  that is projected ahead of the plasma front, so
  guiding the direction of the flow could play a
  role in the evolution of large-scale
  astrophysical jets, in which rectilinear
  structures stretch for remarkably large distances
  with very little deviation
• Plasma-neutral gas mixtures are a unique medium,
  if momentum transport is incorporated between the
  charged fluid and its neutral counterpart.
  Density structures evolve that are hybrids of the
  plasma response to magnetic perturbations, and
  the neutral gas sonic pressure waves. The
  resulting mixture leads to an anisotropic medium
  that can support a large variety of pressure
  variations.
• For more details, see handout.

• Analysis and interpretation of Hinode
  observations of solar flares and related
  phenomena Supervisor Dr L Fletcher, Dr J I
  Khan
• The Hinode ("Sunrise" in Japanese) solar
  satellite was launched in September 2006, and has
  been returning high quality data ever since,
  including coronal images in the soft X-ray range,
  chromospheric images in the optical to
  ultraviolet, photospheric vector magnetograms,
  and extreme ultraviolet spectroscopy of coronal
  and transition-region plasmas. In the rise
  towards the next solar maximum in around 2011 the
  level of solar activity will increase, and Hinode
  will become a prime mission for studying solar
  flares
• The main priorities of this project are
• Analysis of Hinode magnetic field observations
  to identify the locations of photospheric field
  changes
• Imaging and spectroscopic studies of large-scale
  coronal disturbances such as propagating flare
  waves, mass ejections and flows
• Spectroscopic studies of solar flare plasmas .
  For more details, see handout.

• Astronomy with the Square Kilometre Array
• SupervisorsDr G Woan, Dr M A Hendry
• The Square Kilometre Array (www.skatelescope.org)
  is an exciting, highly ambitious project to build
  the world's largest radio telescope. Glasgow is
  part of the UK SKA Design Study consortium, a
  4-year international project which brings
  together European and international astronomers
  to formulate and agree the most effective SKA
  design. The aim of this project will be to
  investigate some of the ground-breaking science
  questions which the SKA will address when it
  becomes fully operational around 2015. These
  questions range from the fundamental physics of
  pulsars and black holes to understanding the
  nature of dark energy and the process of galaxy
  formation. Examples of possible project topics
  include
• mapping the distribution of neutral hydrogen as
• a diagnostic of reionisation in the high-redshift
• universe
• understanding the role of high-precision pulsar
• timing measurements as a probe of gravitational
• wave emission in the galaxy
• surveying the Faraday rotation measure from
  compact polarised sources as a diagnostic of
  cosmic magnetic fields
• For more details, see handout.

• Pulsar Magneotspheres
• Supervisor Dr D A Diver
• Pulsar atmospheres consist of electron-positron
  plasmas. Such plasmas are very energetic, and
  given that the positive and negative species have
  equal mass, these plasmas have unique properties.
  We are investigating wave propagation in
  magnetised pair plasmas, from the perspective of
  trying to understand the wave processes that
  could contribute to the pulsar radiation source.
  To date we have examined the radiation damping of
  quasi-linear electron-positron plasma
  oscillations, using computer simulations. Complex
  analysis has allowed us also to reformulate the
  Bernstein modes in a weakly relativistic pair
  plasma, with a view to studying how such weakly
  damped magnetic modes might act as a vehicle for
  radiation transport in a non-uniform plasma. The
  landau damping of fully relativistic pair plasmas
  is also a developing investigation.
• The project will be concerned with
• developing simulations of the interaction
  between fast particle streams and large-amplitude
  collective oscillations
• extending our analytical attack on realtivistic
  Landau damping, and exploiting the new physics
  that arises and
• creating the necessary relativistic
  transformations that allow the radiation field to
  be translated into the observer's frame.

• Surface flow induced ionization in the Sun
• Supervisors Dr D A Diver, Dr H E Potts
• A numerical and theoretical investigation of
  Alfven ionization processes in strong solar
  photospheric flows.
• The kinetic energy of mixed-species neutral gas
  flowing through a magnetised plasma can result in
  pockets of energetic plasma electrons (confined
  by the magnetic field) that are able to ionize
  specific neutrals in the flow via electron-impact
  ionization. Such  a process has already been
  implicated in creating the anomalous chemical
  composition of the solar wind we aim to extend
  this study by correlating solar surface flows and
  magnetic structures together with improved data
  on solar abundances to clarify the overall
  picture of ionised species evolution in the
  magnetic environment of the sun.
• Specifically, this project will address
• the creation and transport of particular ions
  via interaction with a defined magnetic
  structure,
• the investigation of the differential diffusion
  of minority species in order to model directly
  the resulting abundance anomalies in the solar
  wind.
• This will allow us to incorporate time-dependence
  arising from the photospheric flows and the
  character of the magnetic structures, as well as
  longer timescales invoked by the solar cycle.

• Diagnostics of solar particle acceleration - a
  cosmic prototype
• Supervisors Dr L Fletcher,  Dr E P Kontar, Dr
  A L MacKinnon, Prof J C Brown
• Particle acceleration is a ubiquitous cosmic
  phenomenon from the scale of active galactic
  nuclei down to planetary magnetospheres with the
  resulting fast particles having an energy density
  high enough to influence their environment.
  Acceleration processes are far from well
  understood, either theoretically or
  phenomenologically from data interpretation.
• The nearby sun offers a unique opportunity to
  study particle acceleration via high resolution
  spectra and images at radio to gamma-ray
  wavelengths from ground and space observatories,
  and by direct particle detection in space, As the
  UK Co-I Group on the NASA high energy RHESSI
  solar mission, and with close involvement in
  other solar missions, Glasgow is involved in a
  wide range of theoretical and numerical projects
  on diagnosing data on solar electron and ion
  acceleration. Possible thesis topics include
• data mining and reduction
• signal analysis (spectrum and image
  deconvolution)
• tests of phenomenological models against data
• numerical simulations and analytic modelling
• . For more details, see handout.

• Hot topics in stellar plasma physics mass loss
  and dwarf star flares
• Supervisors Prof J C Brown, Drs M A Hendry, L
  Fletcher, N Labrosse.
• Hot massive stars lose mass in their winds at a
  prodigious rate - as high as a solar mass in
  10,000 years. This has major consequences for
  massive star evolution and for the structure and
  chemical composition of interstellar matter.
• Though it is accepted that these winds are mainly
  driven by radiation pressure, their remain many
  unanswered questions about them
• what other forces - e.g. magnetic, rotational,
  pulsational - generate the diverse structures
  seen in the massive winds of different stellar
  classes - clumps, disks, jets - and
• how does radiation manage to impart such high
  momentum as well as energy to the winds?
• This project will be concerned with
• one or more of these issues via a mix of
  multimode (spectroscopic, polarimetric,
  photometric) analytic and numerical modelling and
  'data-mining' of the rich and growing multi
  wavelength information archive of observations.
• For more details, see handout.

• Self-consistent dust growth in plasmas
• Supervisor Dr D A Diver, Dr H E Potts The
  evolution and character of plasma dust has
  wide-ranging implications for astrophysics and
  laboratory plasmas, including fusion and plasma
  processing.
• Whilst there are many studies of plasma crystals,
  there are fewer investigations of the more
  profound problem of growing the dust from first
  principles directly in the plasma.  Classical
  condensation mechanisms are not as relevant in
  the plasma context, since in the latter the local
  electrostatic conditions can influence enormously
  the conditions for dust growth, leading in some
  cases to naturally occurring prolate-spheroidal
  dust shapes. The implications of non-spherical
  dust grains for electromagnetic extinction and
  polarisation in astronomical observations are
  well-known, but though progress has been made in
  characterising the effects of composite grain
  structure and spheroidal  shapes, there is little
  in the way of a holistic approach to the problem.
• The main aims of this project are
• To model the formation and evolution of dust in
  the original supporting plasma
• To examine the electrostatic charging of dust
  over a range of scales, and its subsequent
  growth, with and without a magnetic field
• To simulate the remote diagnosis of the medium
• For more details, see handout.

• Plasma Sheath stability and plasma acoustics
• Supervisor Dr D A Diver, Dr H E Potts
• A project to model (i) the impact that a plasma
  source can have on neutral gas and (2) the time
  evolution of the sheath around a free-surface in
  a streaming plasma.
• In plasma acoustics, the ion wind and localised
  heating of a plasma source in a neutral gas can
  trigger significant sonic disturbances.
• In the sheath stability studies, the
  electrostatic environment at the perimeter of a
  possibly deformable conducting (or dielectric)
  structure placed directly in a flowing plasma.
• These projects are computational and analytical
  in character, sharing basic plasma physics but
  applied to different situations. Several
  competing scale-lengths will contribute to the
  complexity of the evolution the collisional mean
  free path of the plasma, the free-fall sheath
  length scale, the typical wavelength of
  deformation of the conductor and the scale-length
  for non-uniformity of the plasma flow. The
  competition between these characteristic scales
  will lead to strong time-dependence in the local
  electric field, and the consequence non-linear
  feedback on both the impinging plasma flow, sonic
  disturbances and the free-surface deformation of
  the obstruction.
• For more details, see handout.

• Diagnostic of solar eruptive prominences
• Supervisor Dr N Labrosse, Dr L Fletcher
• Solar prominences are large magnetic structures
  confining a cool plasma in the hot corona,
  surrounding a polarity inversion line in the
  photospheric magnetic field. Typically, the
  prominence plasma is one hundred times cooler and
  denser than its coronal surroundings, raising
  important questions about origin and energy
  equilibrium. Once prominences are formed, they
  can remain stable for over a solar rotation and
  are an integral part of the solar corona. The
  conditions for their stability are inherently
  related to the associated magnetic configuration.
  Some disappear quietly, but most disappear in a
  more dramatic fashion in association with a
  Coronal Mass Ejection (CME). A CME has severe
  impacts on the heliosphere and planetary
  environments, and thus has become a central topic
  of research in the field of Space Weather. The
  aim of the project is to develop a model of the
  plasma during the activation and the eruption of
  the prominence.
• It will be based primarily on non-local
  thermodynamic equilibrium modelling of the
  radiative transfer and the synthesis of spectral
  lines formed under different physical conditions.
  This will be compared with extreme ultraviolet
  observations from SOHO, TRACE, Hinode, and STEREO
  spacecrafts. The work may involve several
  international collaborations, including France,
  Czech Republic, USA. .
• For more details, see handout.

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Stellar Physics Plasma Physics Solar Physics
Cosmology PhD MSc