Starts With A Bang #122 - Galaxy evolution and JWST

About this episode

The episode discusses galaxy evolution over cosmic history and the significance of the COSMOS-Web observing program using JWST data.

It's no secret that the Universe and the objects present within it, as we see them all today, have changed over time as the Universe has grown up over the past 13.8 billion years. Galaxies are larger, more massive, more evolved, and are richer in stars but fewer in number than they were back in the early stages of cosmic history. By looking farther and farther away, we can see the Universe as it was at earlier times, but we're going to be limited in many ways: by how deep our telescopes can see, by what wavelengths they're capable of seeing, and by what small fraction of the sky they're capable of observing. That's why an observing program like COSMOS-Web, the largest, widest-field JWST observing program to date, is so important. It isn't just revealing galaxies as they are nearby (at late times), at a variety of intermediate distances (and earlier times), and at ultra-large distances (and the earliest times of all), but due to its wide-field nature, is revealing galaxy types of varying abundances: the common-type galaxies, galaxies that are representative of more uncommon varieties, and even significant numbers of rare galaxies. And it's this aspect of galaxy evolution that…

People in this episode

Host: Ethan Siegel

Guest: Dr. Olivia Cooper

Topics covered

• galaxy evolution
• JWST
• cosmic history
• observational astronomy
• COSMOS-Web
• universe
• galaxy types

Keywords

• galaxies
• JWST
• COSMOS-Web
• universe
• galaxy types
• cosmic history
• observational astronomy

Mentioned in this episode

Organizations: COSMOS-Web, JWST

More episodes of Starts With A Bang podcast

• Starts With A Bang #130 - the initial mass function of stars · June 6, 2026 · 1h 44m
• Starts With A Bang #129 - Triton and the outer solar system · May 9, 2026 · 1h 36m
• Starts With A Bang #128 - Planet formation and proto-protoplanets · April 11, 2026 · 1h 40m
• Starts With A Bang #127 - Satellites and space pollution · March 7, 2026 · 1h 44m
• Starts With A Bang #126 - The origin of dust · February 7, 2026 · 1h 39m
• Starts With A Bang #125 - Large-scale structure · January 11, 2026 · 1h 33m