Letters of Intent received in 2022

LoI 2024-2175
The first chapters of our cosmic history with JWST

Date: 6 August 2024 to 9 August 2024
Category: GA Symposium
Location: Cape Town, South Africa
Contact: Themiya Nanayakkara (wnanayakkara@swin.edu.au)
Coordinating division: Division J Galaxies and Cosmology
Other divisions:
Co-Chairs of SOC: Michael Maseda (UNIVERSITY of WISCONSIN–MADISON)
Themiya Nanayakkara (Swinburne University of Technology)
Chair of LOC: None (None)



- Physical and chemical properties of the first galaxies in the Universe.
- The role of first stars in reshaping the first billion years of cosmic evolution.
- The role of early small dust-free galaxies to the reionization of the Universe.
- The cosmic transformation from the early massive galaxies in the Universe.
- The abundance and buildup of the massive dusty systems in the early Universe.
- The abundance and quenching mechanisms of the first massive quenched galaxies in the Universe.
- Simulating the first chapters of our cosmic history, current challenges, and how JWST can be used to overcome them.
- JWST observatory updates: what have we learnt about the facility in the first 2 years.
- Complementing JWST with Hubble and ground based facilities.
- Future challenges of JWST.



After decades in waiting, in 2022 the James Webb Space Telescope (JWST) opened up a new window to our cosmos. The renewed infra-red view of our Universe enabled by this facility has already started transforming our view and understanding of the early cosmic processes. Here, we propose to organise a symposium aligned with the 2024 GA for the community (1) to present what the first 2 years of the JWST mission has uncovered and (2) to discuss optimal planning of the remaining lifetime of the telescope to achieve the best scientific return from this groundbreaking facility.

Each of the four instruments on board the spacecraft provides a unique view of the deep Universe. Early Release Science (ERS) programs such as GLASS and CEERS have already shown the combined power of these instruments. From massive bright galaxies hidden in layers of dust to spiral structures in the early Universe has started to question our understanding of galaxy evolution. Deep imaging has already found evidence for the first generations of galaxies, at times in far greater numbers than anticipated. Once calibrations of the instruments are further constrained in the coming months, our early view will surely start to change. This combined with spectroscopic follow ups planned for the Cycle 1 ERS and Treasury programs, JWST will shed the first light into the first stars and galaxies in the Universe.

By 2024, a wealth of data will be available. Deep extragalactic ERS programs would have completed their multi tired observations by early 2023. The different instrument modes used by the ERS teams and the wealth of data products will allow astronomers to understand strengths and weaknesses of the various modes afforded by the facility. With new and improved calibrations, deep extragalactic treasury programs such as UNCOVER would also have completed their observations by mid 2023. These data are public as soon as they are acquired, so the whole community can continue on the learning expedition together. By early 2024, the extragalactic Guaranteed Time Observation programs such as JADES will have been completed, with more than 900 hours of imaging and spectroscopic data. While the very first spectroscopic data will be follow-up of HST targets, by this time we will also have large datasets selected entirely from JWST imaging.

This means, by the 2024 GA, the community would have access to JWST data for over 2.5 years. Significant progress in understanding of the early Universe is expected by then. Therefore, the timing is ideal for the community to come together under the umbrella of the IAU to discuss the discoveries of our early comic chapters and develop an optimal pathway to further strengthen the possibilities of JWST.

Most importantly, the JWST takes on the role of being the “Observatory of the World”. Anyone in the world without any geographic limitations can request access to the JWST. Proposals are only judged on scientific merit and reduced high level data products are made available publicly by STScI. Thus, researchers from developing nations (where funding to access large astronomical infrastructure is limited) have the opportunity to lead their own programs and be a part of the active research community using advanced novel space data. This GA being the very first one in the African continent in the 100+ years of IAU history, we propose to take advantage of this open access policy of JWST research to inspire younger generations alongside the symposium. In addition to traditional outreach talks, we will liaise with the I-HOW ( IAU Hands-On Workshops) initiative to propose for a hands on workshop for 2024 to be held in the proceeding weeks of the GA. With this we will bring researchers actively working on JWST at STScI other institutes in the world to inspire the next generation of scientists in the African continent within the umbrella of the I-HOW program.