Imperial College Astrophysics Consolidated Grant 2019 - 2022

Lead Research Organisation: Imperial College London
Department Name: Dept of Physics

Abstract

Our research in Astrophysics includes the areas of cosmology (the
study of the Universe), the most distant galaxies, exoplanets (planets
around other stars), and gravitational waves (distortion of space-time
predicted by Einstein, and recently observed for the first time). This
work will make a contribution towards answering some of the greatest
questions that can be posed, including: can we find signs of life
outside the solar system? and what is the fate of the Universe? Our
work involves a combination of theory, observations, and laboratory work. We use
cutting-edge facilities such as the Planck and Herschel satellites,
and in the future the Euclid satellite, the Square Kilometre Array,
and the Large Synoptic Survey Telescope. We also develop the
theory that will lead to proposals for the development of the next
generation of satellites and experiments. In addition we measure in
the laboratory fundamental properties of different atoms, for
comparison against observations of the different elements in stars.

Our understanding of the nature of the Universe has changed profoundly
over the past 20 years, since it was discovered that the expansion of
the Universe is accelerating, and as experiments, primarily those
observing the cosmic microwave background, have allowed the accurate
measurement of the parameters describing the Universe - the
proportions of ordinary matter (atoms), dark matter, and dark energy,
and the current rate of expansion. Dark matter clumps gravitationally
and outweighs ordinary matter by a factor 5, but what it consists of
is unknown. The even greater mystery is dark energy, which is causing
the acceleration of the Universe, and which dominates the mass-energy
budget. Our work in cosmology takes different approaches to answering
these problems. But the common theme in our research is the
understanding that advances will come through improved experiments
that measure quantities (cosmological distances, the rate of
expansion) more accurately. The experiments rely on better technology
(e.g. measurements of polarisation of the cosmic microwave
background), better understanding of the physics under study (the
properties of supernovae used to measure cosmological distances), and
better data analysis techniques that improve the precision and
accuracy of the results.

No less profound for humankind has been the discovery, again over the
past 20 years, of planets around many of the nearest stars in our
galaxy, and the first characterisation of other stellar systems. If
the ultimate goal is to discover life on other planets this will be
achieved through successive advances in understanding how different
types of planet (rocky/gaseous, large/small) form around different
types of star (old/young, active/inactive, hot/cool) at different
radial separations, and of how the star over its lifetime can affect
the conditions on its planets. Our work in this area includes
theoretical work to understand the mechanisms by which planets form,
as well as developing a deeper understanding of stellar variability
and how this can subtly bias measurements of the atmospheres of
planets (possibly leading to erroneous conclusions).

A consequence of Einstein's 1915 theory of general relativity, which
describes the curvature of space-time due to mass, is that massive
objects undergoing acceleration radiate energy in the form of
gravitational waves, propagating
at the speed of light. After decades of development work, to
improve the sensitivity of the instruments, gravitational waves were
finally detected in September 2015 by the Advanced LIGO consortium.
This discovery opens up an entirely new way of exploring the universe,
offering rich new possibilities. Our interest in this field is in
thinking ahead, by developing the theory of what might be detectable,
to anticipate how to interpret new measurements, and to guide the
development of the next generation of instruments.

Planned Impact

ASTRONOMICAL ALGORITHMS

Imperial Astrophysics hosts the Imperial Centre for Inference and
Cosmology. The work of the Centre informs our approach to research,
with the emphasis on maximising the scientific return through a
sophisticated approach to data analysis. This approach has very wide
application in industry, and is applicable to almost any quantitative
problem. Examples include: optimising the technology to reduce
climate-change inducing leaks from the gas distribution network; the
analysis of in-vehicle monitoring systems data, contributing to
improving rod safety; the development of astronomical algorithms
involving the handling of large datasets particularly for medical
imaging, but also with applications in the aerospace and security
sectors. Contacts are in many cases first made through enquiries from
industry directed to Imperial Consultants, which is registering
growing demand.


ATOMIC SPECTROSCOPY

We provide atomic data needed in industrial analytical
applications. Glow discharge spectroscopy is used by industry to
analyse very thin (few nm) layers found in manufacturing processes and
the development of new materials. Interested industrial sectors
include life sciences, automobile manufacturing, nano-technology and
thin films. Fourier Transform spectroscopy also has wide
application. Pickering runs the Tropospheric Airborne Fourier
Transform Spectrometer (TAFTS) instrument. TAFTS is the first
far-infrared spectrometer capable of high resolution far IR
tropospheric in situ measurements. These data are revealing the role
of water vapour and cirrus clouds in the regulation of the Earth's
climate.

OUTREACH

We will continue to engage in a wide range of public outreach
activities, including science and literary festivals, school visits,
exhibits (especially the Royal Society Summer Exhibition), public
lectures, blogs (by Jaffe and Clements), popular science books (Trotta
and Clements), radio and TV appearances and interviews, and science
consulting to the science fiction community.

Publications

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