Dr Helen Fraser

Aim: The overarching aim of our research is to understand the nano-scale physical properties and structure of molecular ices in star-forming regions, and the impact of such properties on astrophysical-scale effects in the same environments, i.e. collisions leading to planet formation and chemistry leading to complex molecule formation, adsorbate gas traps, and desorption. Objective: This PhD programme has two specific objectives (a) to design and develop a dedicated low-pressure / low-temperature experimental system for forming, manipulating and destroying multi-component condensed molecular systems, for studying astrophysical ice analogues with NIMROD and SANS2D and (b) to couple large-scale molecular dynamics simulations of multi-component ice formation / evolution with measurable properties from neutron scatterring studies, including material density, porosity, structure, clathrate formation and H-bonding. Outcomes: This 4-year joint OU-ISIS studentship, which combines condensed matter experimental techniques in neutron scattering with molecular dynamics simulations, will address three key questions in astrochemistry research:- 1. What is the structure of water-ice in space? 2. When is water ice structure impacted by physical factors such as temperature, pressure or time? 3. How is water ice structure imapcted by chemical factors such as adsorbates, chemical reactions or clathrate formation? Whilst the scientific returns on this project will be focused towards astronomy stakeholders, the facilities returns will be focused on impacting a wider range of ISIS users, particularly those associated with disordered materials. The developments in coupling molecular dynamics with ISIS data analysis and interpretation will benefit users of NIMROD, SANS2D and SANDALS, particualrly where the system studied is dynamical or metastable and therefore evolving as a function of experiment time or temeprature. The new experimental faciltity will enable in situ formation of samples (probed by neutrons) as well as in situ destruction of (the same) samples. This opens up new temerpature-pressure parameter space to experimenters, as well as a new method, for sample preparation.

Our scientific aim is to describe, qualitatively and quantitatively, the collisions that dominate the earliest stages of icy planetesimal formation, to answer how do planets form? a key science challenge in STFC’s Astronomy Core programme. This studentship will develop, test and exploit the underpinning video camera technology necessary to realise this scientific ambition, in collaboration between the Open University (OU) and Dynamic Imaging Analytics Ltd (DIAL). How do planets form? The first stage of planet formation is the accumulation of tiny icy grains into aggregates. Low-velocity collisions then build up icy pebbles, which subsequently form pebble clouds. These contract to form icy planetesimals, which eventually form planets, due to gravitational forces and runaway growth. Planet forming models use a single parameter to describe such collisions, the coefficient of restitution (COE) which is the ratio between the relative velocities of the particles before and after a collision. This quantity can only be determined empirically, driving the need for laboratory experiments on icy grain aggregation. Our overarching experimental concept is to watch what happens when thousands of well characterised icy spheres are released into a small collision volume, held at low temperature and pressure, during suborbital microgravity, such that their velocities are sub cm/s, asking how do icy grains grow from nm to cm scales? Initially the grains will collide and stick, forming 100’s of aggregates, which will collide again and build some cm-sized pebbles, on timescales of tens of seconds. In addition to a qualitative description, we require a full 3D reconstruction of the process, from which we extract quantitative collisional data, testing trends in COE as a function of ice grain properties.

STFC Open 2018 DTP

Our research programme, Astronomy at the Open University, covers the breadth of cosmic evolution, from dark energy to the birth of planets. We do this research by observation, laboratory experiments, simulations and modelling. We use purpose-designed laboratories and instruments, and instruments on telescopes and spacecraft to make our observations and measurements. Our group is based in the Department of Physical Sciences at the OU. So what are we trying to find out? We have 8 separate projects, from exoplanets and stars to distant galaxies. We already know a lot about how the Solar System came about. The Sun and planets formed from a cloud of dust and gas about 4570 million years ago. The cloud collapsed to a spinning disk and dust and gas spiralled inwards. The core of the disk became hot, forming the Sun, while the leftover dust and gas formed the planets. Boulders gravitated together to make planets, but no-one knows how the dust grains became boulders. We are experimenting with colliding centimetre-sized particles in zero-gravity conditions to see if they stick together, to find the missing link in how planets form. We also look at processes that cause stars to change as they age. Only recently has it been recognised that so many stars are binary systems, where two or more stars are in close association and affect each others' motion. Such systems affect the way mass and energy is lost from a star, and how they are transferred into the interstellar medium. We will study how 'binarity' affects the behaviour of massive stars (>20 times the mass of the Sun) and low mass stars (< the mass of the Sun), and how star populations change as they age. Studying these effects is vital, because the environment of a star influences any planets that surround it. Many hundreds of planets have been discovered around other stars (exoplanets) and we are working to describe the range of properties of these planets, especially when they are located close to their central star. A star can even completely destroy a close-in exoplanet, which could be an important new source of dust in the nearby universe and even in distant galaxies in the early Universe. Also in the early Universe, we can use the way that galaxies warp space and time to learn about the dark matter that surrounds them, and the dark energy that drives them apart. What else do we do? We build and test instruments for ground-based telescopes and for space missions, striving to make them smaller and lighter, and explore how they can be used on Earth for medical or security purposes. One of the most important benefits of our research is that it helps to train and inspire students: the next generation of scientists and engineers. We also enjoy telling as many people as possible about our work, and what we have learned from it about our origins.

What is microgravity? Why do scientists use it? Our overarching aim is to produce a series of short, humorous and factual videos, called "60 Second Adventures in Microgravity", aimed at a broad audience of children and adults, to enable them to understand why the UK is involved in microgravity research, what UK scientists do in microgravity research, and how this work benefits our everyday lives. The proposal is based on the OU 60 seconds series, produced by applicant Catherine Chambers, which has covered a number of subject areas. The series started with series of outstandingly successful animated short-form videos for the web - on the history of English, narrated by Clive Anderson, e.g. http://youtu.be/r9Tfbeqyu2U (600,000 hits on YouTube). This was followed by Sixty Second Adventures in Thought (see stills in additional material), narrated by the comedian David Mitchell, covering philosophical topics (see e.g. http://youtu.be/skM37PcZmWE, over 30,000 hits in just one month). Theseave more than three million views in total to date. More recently, this was extended to astronomy, planetary science and particle physics, again narrated by David Mitchell and funded by STFC. This work will build on this successful formula to generate a novel Sixty Second Adventures in Microgravity, promoting the interests of UKSA and the UK ELIPS scientific community to the general public. The remaining 3 applicants BR, SG and HJF all are involved in current ELIPS research projects. We propose to produce 4 episodes; Microgravity - what is it?: This first video will aim to explain to the audience, what microgravity is - starting from a sketch of the Earth with a cable going to a big switch, and flicking the switch (to switch gravity off) which makes everybody / everything float away. Obviously we cannot turn gravity off, but we need to recreate conditions of "free-fall" so that from the frame of reference within the "microgravity" environment can be recreated. The video will explain the ways we can do this, focusing on ground-based microgravity platforms. Parabolic Flights: fancy getting sick whilst doing your science? Hurtling towards the Earth in an aeroplane? That's what OU scientists do...How do we build planets? Scientists don't know, but they test how the building blocks of Solar systems form by having a great big, slow-motion snowball fight - OK not really - but they use microgravity platforms to collide ice particles with each other. These ELIPS based experiments show that "traffic jam" effects are more important in planet-forming disks than collisions themselves. This will be the one video based on existing OU expertise in ELIPS research. Understanding the aging population: Bed-rest is another way to exploit the "microgravity environment". Imagine sleeping almost upside down for 6 months and being paid for it... luxury - but why do scientists want people to do that? With an ever aging population, issues of poor blood circulation, osteoporosis and muscle wasting are important to understand so that we can maintain the health and wellbeing of the older generation (as well as medical rehabilitation patients e.g. long-term injury patients such as car-crash victims or members of the armed services). Cell Biology: Space might not be the first place to think about biology - given that it's a vast empty expanse of vacuum, and it's still not clear where life originates. But microgravity research shows us cells are pretty clever - they realise in microgravity there isn't an up or down, they change on a molecular level to adapt to the microgravity environment. The basic signalling systems in cell biology are the same systems that result in muscle degradation and cell changes in microgravity environments. And when one tests the resilience of microbes to the space environments - only those with certain genes and protein sequences survive...a kind of survival of the space fittest? And a clue where we come from? Perhaps.

Financial support to enable my participation in the IAU General Assembly in Honolulu, Hawaii, USA, in August 2015. This meeting, held tri-annually to bring the worldwide astronomical community together.

In the regions of space where stars and planets form, chemistry also happens. In fact, molecules are a paramount tool in astronomy to enable us to extract the chemical and physical conditions in such regions, and therefore say something about how the processes of star and planet formation happen. Many of these molecules are generated through reactions in so-called ices, molecules that have frozen out onto the surfaces of small carbonaceous and silcaceous dust grains during the earliest stages of star-formation. As these astronomical regions evolve, the ices are processed, by heat and star-light, or even interaction with more atoms and molecules, until complex chemicals form. As the stars first start "shining" most of the ice material is converted back into gas, and we can then spot all these complex chemical species in the gas-phase using ground- and space-based telescopes such as ALMA, Herschel and IRAM. A key question for astronomers is to understand which molecules are present in star-forming regions and how much of each molecule is there, and to explain the answers. The explanations rely on us understanding all the chemical and physical processes occurring, which is almost impossible. Instead, we can make exceptionally good guesses, by combining controlled laboratory experiments which tell us about the chemistry ices undergo, with observations where we can spectroscopically identify icy material, or gas-phase molecules, and models, which provide a vital missing link between the two - taking lab data and using it to explain observations, or taking observational constrains and testing chemical processes against those observed in controlled conditions. Astronomers therefore have key molecular data needs. Observers need laboratory spectra which can be compared with observations to extract information regarding the chemical constituents of ice in star-forming regions; modellers need constraints on which ice constituents to start their modelling process from, and then descriptions of all the chemical processes these ices undergo - data which can only be provided by laboratory experiments. This means that all research in this field is reliant on good quality, validated chemical reaction data and ice spectra. The aim of our proposal is threefold (a) to provide an open-source python library of astronomical software to astronomers which takes laboratory spectra of ices in whatever format and converts it to a form where the data can be compared with observations, and then uses these data to extract the ice constituents (b) input the constraints on ice constituents determined from observation (using lab data) into models that can identify the key physical and chemical parameters that must have existed for such ices to evolve generating a 'plug-in' programme to execute this for other modelling users and (c) link ice constituents and chemical conditions back to gas-phase species detected in star-forming regions. In addition, the project will allow us scope to identify where key laboratory data is currently missing from the needs identified by observers and modellers, and initiate the process to add this data to pan-European efforts on spectra and chemical reaction databases which are then validated and standardised for broader use in the scientific community.

The aim of our programme in Astronomy & Planetary Science at the Open University (APSOU) is to carryout detailed investigations of the origin and evolution of galaxies, stars and planets with a special emphasis on our own Solar System through a combination of observation, simulation, laboratory analysis and theoretical modelling. Our research is divided into two broad areas, reflecting the historical research strengths. This research programme is well-matched to both nationally- and internationally-agreed research imperatives. In its final report, A Science Vision for European Astronomy2, Astronet’s Science Working Group identified four broad areas of strategic importance; our research covers major topics within each of these areas. APSOU projects also map onto two of the four Science Challenges that form STFC’s Road Map3 for science (‘How did the universe begin and how is it evolving?’ and ‘How do stars and planetary systems develop and is life unique to our planet?’). The present APSOU programme comprises 20 projects (labelled A to T), of which 6 are for consideration by the Astronomy Observation (AO) panel, 1 for Astronomy Theory (AT), and 13 for the Planetary Studies (PL) panel. The AO projects cover the breadth of the 7 themes recognised as UK strengths in the report of STFC’s Astronomy Advisory Panel (AAP), whilst the 13 PL projects are directed towards answering questions raised in two of the three themes identified as UK strengths in the roadmap of STFC’s Solar System Advisory Panel (SSAP)4.