Hertfordshire Astronomy 2015-18

The Centre for Astrophysics Research carries out observational programmes spanning the wavelength range from X-ray to radio - supporting this by computer modelling and simulation. Our research ranges from observations of high-redshift galaxies at long wavelengths through to novel statistical analyses of observations seeking to detect planets outside our Solar System. In between these extremes, we carry out the largest multi-wavelength surveys conducted to date to understand the properties of the Milky Way and Magellanic System. Our research makes use of observations from all of the main European and international astronomical observatories, including ground-based observatories at optical, radio and submillimetre wavelengths, and space observatories at wavelengths ranging from the far infrared to X-rays. Computer simulations gives us a better understanding of the physical processes detected in our observations, and we need to apply advanced data-mining techniques to work with the ~terabyte datasets we are generating. Below is a brief description of our research in each of these areas.

We perform searches of nearby stars to discover planets. We especially target low mass M stars since they are the dominant type of star in the Universe and have not yet been searched. We focus on detection through Doppler wobble and by looking for planets periodically eclipsing their parent star. During the period of the grant we expect to make the first detections of Earth-mass planets in the habitable zones of nearby stars. We also discover, follow-up and model the properties of the coolest brown dwarfs whose temperatures overlap with those of planets. These studies aim to clarify the population of brown dwarfs and to establish how their modes of formation fit in with those of their brethren of different masses, ie. heavier (stars) or lighter (planets).

The Milky Way is our home galaxy. Material within it, in the form of gas and dust is the raw material for forming stars and planetary systems. At the end of stellar lives some of this material remains locked up in stellar remnants but much of it is returned in late superwind phases and supernova explosions. The cycle between accretion in youth and outflow in old age enriches the gaseous medium and rules its dynamics, via the thermal and mechanical energy injected into the
gas. By using large area imaging surveys, our research looks at how gas, dust and stars within the Milky Way and its major satellite, the Magellanic Clouds, are linked up. Our surveys span the optical to sub-mm domains tracing stars, extinction, molecular clouds, their dust properties and associated star formation.

Looking beyond the Milky Way, it is possible to appraise how stars form and evolve in different environments, from small dwarf galaxies to the outer parts of other galaxies like our own. We study the gas content of galaxies, providing the material for star formation, and link what we find to stellar populations and to star forming regions in the full range of local galaxies. By understanding the processes that trigger star formation and stellar evolution in the nearby Universe, we can apply this understanding to the very earliest galaxies and the first generations of stars in the distant Universe. Indeed some of our work focuses on high redshift galaxies detected with great efficiency at sub-millimetre wavelengths, and look forward to exploiting ALMA for such studies.

A new generation of surveys is mapping out the most distant galaxies, and allows us to investigate what links the processes of star formation and the growth of supermassive black holes. We also use detailed X-ray and radio
observations to measure the energy injected by jets ejected from supermassive black holes into distant galaxies and clusters of galaxies, affecting star formation and gas properties, and playing a long-term role in their evolutionary history.

The public engagement programmes of the Centre for Astrophysics Research (CAR) will benefit the following: (i) the public through its Open Evenings at the Observatory. Six events a year are normally oversubscribed with bookings of ~400 per event. A large fraction of the visitors are family groups - which is important as parents, along with teachers, are most influential in the career choice of young people. A large number of activities engage the visitors so they get an understanding of a working observatory, learn what scientists do, and hear about some of their front line research; (ii) the Observatory hosts about 50 group visits annually, including private parties, brownie and scout troops. The programme, being similar to that of Open Evenings, gives the many young people attending the same experiences; (iii) CAR delivers 'cutting-edge' astronomy courses to teachers, including those whose initial training was not in physics. Delivered at the Science Learning Centre co-located with the Observatory (now a Science Learning Regional Consortium responsible for almost 50% of English schools) it helps teachers to better understand some of the concepts they teach, and gives them increased confidence to deliver the material in their classes; (iv) CAR continues to work with Astrium (now Airbus Defence and Space) on the EChO project (Exoplanet Characterisation Observatory) with related research and technology assessment exercises. This work focuses on simulating the expected properties of EChO M dwarfs and their transiting planets, and how these affect (and constrain) technological aspects of the proposed mission.

The above programmes have run for many years and will continue to do so as there is a clear demand and the extensive feedback remains very positive. New programmes, who they benefit and in what ways they will benefit include: (i) a proposal, which will be resubmitted to the STFC PE Small Awards, will take advantage of the automation of five of the seven domed telescopes, typical aperture 0.4m, to offer teachers the opportunity through both face-to-face and a web-based course to acquire the skills to propose observations, access the already considerable archive and most importantly to develop science-driven projects for their students. Although such opportunities exist on larger telescopes a key aspect of this proposal is that it will show what science can be done on a size of telescope that schools could aspire to; (ii) Dr James Geach, a recent appointment, and a Royal Society University Research Fellow (2013-18), is a member of the SpaceWarps 2 project. This provides CAR with the opportunity to be directly involved in a citizen science project, with - in this case - members of the public examining astronomical images to find galaxies so massive that they warp space and time (gravitational lensing); (iii) A few years ago UH, together with Manchester, Leeds & Oxford invested £125,000 each in the Consortium of Universities for Goonhilly Astronomy (CUGA) and in the wider goals of Goonhilly Earth Station Ltd (GES Ltd). The aim is develop Goonhilly's large dishes for radio astronomy, deep-space communication, and associated science and technology outreach. Progress to date has been slow, however very recently GES have now managed to complete the purchase option with BT and are now in ownership of the site. Although CAR will be involved in the scientific development of the facilities it will also be able to use its considerable experience to help develop the outreach programmes. These will be for the public visiting the southwest who will be able to learn about the technical and engineering developments that are part of modern communications and radio astronomy.