Understanding the physical processes that led to the formation of the first stars and galaxies is one of the
most exciting issues in modern astronomy and physics as a whole. This is a complex problem that involves a
range of scales from the small, where black holes (BH) and stars form, to the large, where the circumgalactic
and intergalactic media (IGM) are ionised and chemically enriched. To make progress we must address a
number of astrophysical challenges, e.g. star- and BH-formation, heavy element production and radiative
transfer through multi-phase environments. Importantly, advancing this field may reveal evidence of new
physical processes such as primordial BHs of non-stellar origin and even fundamentally new ingredients of
the universe.
The required observational data must come from the first billion years after the Big Bang – an epoch that has
escaped detailed observations until recently. This is because of the necessity for sensitive instrumentation
operating at wavelengths longer than 2 μm beyond the capabilities of the Hubble Space Telescope (HST)
and ground-based observatories. Recently, however, the observational situation has been completely
revolutionised by the advent of the James Webb Space Telescope (JWST). With a larger aperture and an
extended wavelength coverage, JWST offers unrivalled opportunities for studies of early galaxies. A major
advantage is its extensive suite of instruments, which provide broad- and intermediate-band imaging
capabilities as well as multi-slit and slitless spectroscopy with a range of resolutions.
We are proposing a MIAPbP workshop to bring together observers and theorists to achieve a consolidated
physical summary of the exciting new results from the first four years of JWST science operations, which will
offer a valuable landmark for the community. However, we will also discuss future plans for JWST, guided by
theoretical developments. What should JWST achieve during the next five years? This question is
particularly relevant in an era where the Square Kilometre Array (SKA) will chart the distribution of neutral
hydrogen during the reionisation era and ESO’s Extremely Large Telescope (ELT) will complement JWST
with exquisite angular resolution enabling resolved studies of individual sources of interest. We have
assembled an enthusiastic group of young and senior participants eager to consider the above challenges
and, via our proposed workshop, willing to play their part in planning a continued revolution in our
understanding of the earlier galaxies.