Galaxy Formation and Reionization: Key Unknowns and Expected Breakthroughs by the James Webb Space Telescope

By Brant Robertson. Annual Review of Astronomy and Astrophysics, 2021

135 citations recorded by the source corpus.

The launch of the James Webb Space Telescope (JWST) in late 2021 marks a new start for studies of galaxy formation at high redshift ( z ≳ 6) during the era of cosmic reionization. JWST can capture sensitive, high-resolution images and multiobject spectroscopy in the IR that will transform our view of galaxy formation during the first billion years of cosmic history. This review summarizes our current knowledge of the role of galaxies in reionizing intergalactic hydrogen ahead of JWST, achieved through observations with the Hubble Space Telescope and ground-based facilities including Keck, the Very Large Telescope, Subaru, and the Atacama Large Millimeter/Submillimeter Array. We identify outstanding questions in the field that JWST can address during its mission lifetime, including with the planned JWST Cycle 1 programs. These findings include the following: ▪ Surveys with JWST have sufficient sensitivity and area to complete the census of galaxy formation at the current redshift frontier ( z ∼ 8–10). ▪ Rest-frame optical spectroscopy with JWST of galaxies will newly enable measures of star-formation rate, metallicity, and ionization at z ∼ 8–9, allowing for the astrophysics of early galaxies to be constrained. ▪ The presence of evolved stellar populations at z ∼ 8–10 can be definitively tested by JWST, which would provide evidence of star formation out to z ∼ 15. Expected final online publication date for the Annual Review of Astronomy Volume 60 is August 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/06ffab5f7dd5329cfb830d681a16ac198346bdbf

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In Astronomy and Astrophysics

1. R. Somerville
2. Christopher J. Conselice
3. P. Hopkins
4. R. Dav'e
5. L. Hernquist
6. C. Conroy
7. A. Dekel
8. P. V. van Dokkum

In Instrumentation

1. Christopher J. Conselice
2. R. Somerville
3. C. Conroy
4. R. Dav'e
5. A. Dekel
6. P. Hopkins
7. P. V. van Dokkum
8. L. Hernquist

Citations in the corpus

• A Comprehensive Study of Galaxies at z ∼ 9–16 Found in the Early JWST Data: Ultraviolet Luminosity Functions and Cosmic Star Formation History at the Pre-reionization Epoch (2022, background): “One of the most important goals in astronomy today is to understand galaxy formation from the birth stage to the current stage (Stark 2016; Dayal & Ferrara 2018; Ouchi et al. 2020; Robertson 2022).”
• A Long Time Ago in a Galaxy Far, Far Away: A Candidate z ∼ 12 Galaxy in Early JWST CEERS Imaging (2022, background): “…Hubble Space Telescope (HST) pushed our cosmic horizons well into the epoch of reionization, the time when energetic photons (presumably from massive stars in early galaxies) ionized the gas in the intergalactic medium (e.g., Finkelstein 2016; Stark 2016; Robertson 2022, and references therein).”
• CEERS Key Paper. I. An Early Look into the First 500 Myr of Galaxy Formation with JWST (2022, background): “The epoch of reionization marks the period when energetic photons (presumably from massive stars in early galaxies; e.g., Stark 2016; Finkelstein et al. 2019; Robertson 2022) ionized the gas in the intergalactic medium (IGM).”