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.
The launch of the James Webb Space Telescope (JWST) in 2021 has revolutionized our understanding of the early universe, with over 300 scientific articles published on early galaxies and black holes since operations began in July 2022. The telescope has dramatically increased our detection and characterization of high-redshift galaxies and AGN, and has led to several puzzles that include a large number of luminous and massive galaxies, and a high abundance of AGN. This is an incredibly exciting and dynamic period in observational astronomy. Yet there is still no clear picture emerging of the most basic questions that motivated JWST in the mid-1990s. When did the first galaxies emerge from darkness? What seeds led to the SMBHS that fuel quasars as early as at times corresponding to redshifts z~7? How did reionisation progress and what were the contributing sources? Fortunately, JWST will not be alone in exploring this era. Both the Atacama Millimetre Array (ALMA) and soon the Square Kilometre Array (SKA) can provide complementary data on, respectively, the dust content of early galaxies and the topology of the neutral IGM. Shortly thereafter, ESO’s Extremely Large Telescope (ELT) will offer higher angular resolution and improved signal to noise measurements compared to JWST, enabling new insight into the resolved dynamics, stellar content and physical processes in selected sources.
This four-week MIAPbP workshop will 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. We will review the census of early star-forming galaxies, early BH demographics and growth mechanisms, the ionizing properties of early sources and their role in reionization, and the prospect of detecting pristine stellar populations. We will thus discuss future plans for JWST, guided by theoretical developments. What should JWST achieve during the next five years and what should our observing strategies be with complementary and future facilities like ALMA, SKA, and ELT?