An unprecedented convergence of cosmological hydro-dynamical simulations and powerful observational facilities is poised to revolutionize our understanding of galaxy evolution, particularly in the (still poorly explored) high-redshift (z>1) Universe, where the bulk of the stellar mass and black hole assembly took place. Recent years have seen an explosion of multi-wavelength data, from instruments like Chandra, HST, Herschel and ALMA, which have enabled us to map the evolution in galaxy properties (e.g. star-formation rates, masses, sizes, gas fractions etc.) and probe their co-evolution with black holes out to z~3. The field is poised for yet another revolution towards the turn of the decade, both in terms of the ground-breaking depth and area offered by future surveys (e.g. LSST, EUCLID, eROSITA etc.), and our ability to comprehensively probe galaxy evolution all the way up to the epoch of reionization, using instruments like the JWST and the E-ELT.

Against this backdrop of observational work, a significant and exciting advance is the advent of a new generation of full hydro-dynamical simulations in cosmological volumes, which offer detailed survey-scale predictions that can be compared to current and future surveys. UK researchers, with their strong tradition of leadership in theoretical modelling, have leading roles in the development and exploitation of these simulations (e.g. HORIZON-AGN, EAGLE, Illustris). In concert with current and future observational datasets, these models will, over the next few years, play a fundamental role in understanding the processes that drive stellar mass and black-hole growth and morphological transformations over cosmic time. The time is therefore ripe for a meeting that discusses the performance of these models and builds the required synergies between theorists and observers that will enable us to use these simulations in conjunction with current and future surveys.

Timeliness and benefit to the UK astrophysical community

The meeting will be timely, because hydro-dynamical cosmological simulations have just matured (with various groups having recently published their first tranche of papers), and because key observational facilities with strong UK involvement (e.g. LSST, EUCLID, SKA precursors) will be commissioned or begin operations within the next two years. Our aims are to (1) bring together theorists from across the UK, in order to foster collaboration between different simulation groups, (2) inform the UK’s observational community of the capabilities of today’s state-of-the-art simulations, and (3) lay the groundwork for the exploitation of forthcoming datasets, by stimulating collaborations between theorists and observers. By providing a focal point for theorists, and bridging the gap between theorists and observers, this meeting will enable the UK community to better position itself, both for the exploitation of current instruments, and for the theoretical analysis of data from next-generation ‘Big Data’ facilities like LSST, EUCLID and the SKA, in which the UK community has a significant stake.

Topics to be covered

  • The current state-of-the-art in cosmological simulations: prediction of galaxy properties and the intergalactic/circumgalactic medium
  • Critical discussion of sub-grid recipes (e.g. star formation, stellar and AGN feedback)
  • Confrontation of predictions with current datasets: where do models succeed? where do they fail and why? what future datasets can constrain models further?
  • Theoretical predictions for future Big Data instruments in which the UK has strong involvement (e.g. LSST, EUCLID, SKA) with a view to consolidating UK leadership in these projects