Plenary Talks
Dr. Sandro Tacchella
First Insights from JWST: Star Formation in Cosmic-Dawn Galaxies
Monday 3rd July 2023 @ 11h15After successful deployment and commissioning, JWST has now been delivering data for over a year. In this plenary talk, I will give an overview of the first-year surprises and discoveries, zooming in on some of the earliest galaxies and presenting new results on the spatially resolved growth histories of high-redshift galaxies. Specifically, I will discuss the structural and stellar population properties of the galaxies at the redshift frontier, with redshifts z>10. I will then connect the mode of star formation with the early enrichment of galaxies: for galaxies where we have constraints on the gas-phase metallicity (at redshift of z=8), I will discuss how star-bursting galaxies can have different gas-phase metallicities due to internal and external mechanisms that drive the starburst. Finally, I will focus on the structural evolution of galaxies, presenting how bulges form within galaxies at z>7. I will wrap up by highlighting what JWST will be able to deliver regarding high-redshift galaxy evolution in the upcoming years.
Prof. Erminia Calabrese
Precision cosmology with the Cosmic Microwave Background
Monday 3rd July 2023 @ 12h00The use of the Cosmic Microwave Background (CMB) to study the physics of the Universe is one of the greatest success stories of modern cosmology. This light, travelling since ~380,000 years after the Big Bang, contains relic signatures of the physical processes that took place much earlier, at incredibly high energies, as well as unique features allowing us to determine precisely the abundances of the main constituents of our Universe, which govern its evolution on large scales. In particular, during the last three decades, the astonishing agreement between the theory and increasingly-precise observations of the CMB has led to the establishment of our standard model of cosmology. While the parameters of this model have been constrained to sub-percent precision, many fundamental questions about the Universe are still unanswered. In this talk I will give a snapshot of where we are in CMB cosmology, how we got here and where we are heading next, as new, more powerful CMB data are being collected, analysed and planned for.
Dr. Rowan Smith
Star Formation in the Galactic Cradle
Tuesday 4th July 2023 @ 14h00Star forming clouds are not islands in and of themselves, but instead form out of, and are embedded within the interstellar medium of our Milky Way galaxy. Large scale galactic structure such as spiral arms, and clustered supernovae feedback from previous generations of star formation drive large scale turbulence which influences fragmentation within star forming clouds. Differential rotation within the disc stretches out large filaments of HI, within which molecular filaments are embedded. Magnetic fields generated by the large-scale dynamo thread the galaxy and influence the alignment of filamentary clouds and how they fragment. Thus, the history of star formation is intrinsically linked to the galactic environment in which it forms. However, star formation is almost always treated as a sub-grid process in galaxy simulations, while galaxy scale forces are neglected in studies of local star formation. In this talk I will use my own Cloud Factory simulations suite, as well as other results from the literature, to explore how star forming clouds and galaxies are linked, and the implications for our understanding of both.
Prof. Richard Mushotzky
A Journey of 50 years and a Few Gigaparsecs-How Recent X-ray Results Have Changed Our Understanding of AGN and a Peek at the Future
Tuesday 4th July 2023 @ 14h45Since the dawn of x-ray astronomy 60 years ago, finding and studying active galaxies (accreting supermassive black holes) has been a prime area of study. I will very briefly summarize the events of the last 5 decades concentrating on my own research. Over the last decade a major change in our understanding of these objects have been enabled by the first sensitive hard (E> 10 keV) all sky x-ray surveys, followed up by detailed observations across the entire electromagnetic spectrum. I will briefly summarize some of a major changes in our understanding of the nature of the host galaxies, the relationship to star formation, black hole mass, AGN fueling, and the implications for the theoretically predicted effect of feedback at low redshifts. I will examine the next steps in our understanding, stressing the soon to be launched XRISM x-ray spectroscopy mission and discuss the more distant future, focusing on the AXIS x-ray probe concept.
Dr. Hannah Wakeford
The data and dynamics of exoplanet atmospheres
Wednesday 5th July 2023 @ 11h00Exoplanet research has revolutionized our understanding of planetary systems beyond our own solar system. In particular, characterizing the atmospheres of exoplanets is crucial for determining the nature of their environment and tracing their formation history. In this talk, I will explore the latest exoplanet atmospheric characterization with Hubble and JWST from the UV to the mid-IR across a wide population of exoplanets. I will discuss the challenges in analysing the observations from systematics to chance events. I will also highlight the ways we interpret the spectra to understand the chemistry and dynamics of the atmosphere. I will finish with some of the most recent discoveries and future prospects for exoplanet atmospheric characterization.
Dr Tana Joseph and Prof. Peter Coles
Diversifying Diversity
Wednesday 5th July 2023 @ 11h45We tend to think of diversity along the principal axes of gender and race but there are many other aspects to be considered. In this session we shall discuss the need to diversify the theme of diversity, illustrating some of the ideas with examples drawn from large international consortia which are increasingly important for research in astrophysics and cosmology.
Prof. Gavin Dalton
WEAVE: The WHT’s new Wide-field spectroscopy facility
Thursday 6th July 2023 @ 14h00I will describe the development and application of the WEAVE facility upgrade for the William Herschel Telescope. !2 years in development, WEAVE uses a pair of robots mounted at the telescope prime focus to deploy up to 950 optical fibres over a two degree field of view. The fibres (100km in total) are routed down the telescope to a new high performance spectrograph mounted in an enclosure on the Nasmyth platform, which provides 16000 spectral pixels for each target. Representing an improvement of more than two orders of magnitude in the capability of the telescope, WEAVE can deliver spectra for nearly 10000 targets in a single night of observations.
Exploitation of this facility is centred on a 5-year public survey programme covering the topics from the dynamics and evolution of the Milky Way through the formation of galaxies in the distant Universe. In this talk I will describe the motivation and development of the design and present some very early results from the ongoing commissioning process.
Dr. Andy Rivkin
The Double Asteroid Redirection Test: A Crash Course in Asteroid Defense
Thursday 6th July 2023 @ 14h45Asteroid impacts have profoundly shaped the history of life on Earth and have been implicated in at least one mass extinction event. Planetary defense is dedicated to predicting and preventing such disasters in the future. The Double Asteroid Redirection Test (DART) mission was launched in November 2021 and arrived at its target, the asteroid moonlet Dimorphos, on September 26, 2022. DART’s goals were to validate a planetary defense technique known as “kinetic impact”, which is changing an asteroid’s orbit by colliding a mass with it. This presentation will include an overview of the mission and its results, including data from the spacecraft and its companion cubesat LICIACube (contributed by the Italian Space Agency), imagery and spectra from ground- and space-based telescopes, and analysis.
Dr. Payel Das
How satellites have shaped our Milky Way: the view from Gaia
Friday 7th July 2023 @ 11h00The Gaia spacecraft has brought our Milky Way into focus in an unprecedented way. The synergy with ground-based spectroscopic surveys has provided us with photometry, 6-D phase-space coordinates, and spectra for millions of stars. I will firstly discuss the constraints the inferred dynamical, chemical, and age properties of stars have placed on a major accretion event nine Gyrs ago that may have thickened the pre-existing disc and birthed a new thin disc. I will then discuss how interactions between the Miky Way and its satellite system continue to shape the discs until the present day. To finish, I will say some words about what our new perspective on the formation of the Milky Way can reveal about the evolution of disk galaxies throughout the Universe.
Dr. Antoine Strugarek
Understanding the magneto-rotational evolution of stars
Friday 7th July 2023 @ 11h45The magnetic field of our Sun is generated through an internal dynamo process leading to a cyclic variability of about 11 years. This cyclic field shapes the environment of our star and determines the connectivity in the heliosphere from the photosphere to the Earth orbit and beyond. The Sun has probably not always possessed such a cyclic field, nor should it keep it as it ages. Indeed, stars like the Sun spin down as they age, which greatly influences the dynamo processes they are able to sustain.
I will present ongoing efforts to model stellar dynamos in an evolutionary context. Based on numerical studies, we have recently proposed a unified view of the types of cycles solar-like stars are able to sustain. These results are confirmed using both simplified, mean field approach as well as 3D turbulent numerical simulations using various approximations. They show a tight link between the large-scale rotation profile within solar-like star, and the type of cyclical dynamos they are able to sustain. In this context I will detail the expected energy budget of such stars, and its implication for stellar dynamos. I will finally end with recent efforts where we start coupling dynamo action acting over decadal timescales with the response of the environment of the star, its dynamical corona.