Tue, 25/10/202212:30-13:30
Repeats every week every Tuesday until Mon Feb 13 2023 except Tue Oct 25 2022
Ross 216
Speaker: Steven Finkelstein (The University of Texas at Austin)

Title: Pushing into the First 500 Million Years after the Big Bang with JWST

Abstract: The reionization of the intergalactic medium (IGM) marked the time when energetic radiation from the first luminous sources in the early universe (presumably stars and galaxies) ionized the gas suffusing the space between galaxies.  This period not only marks the last major phase transition of matter in the history of the universe, but also represents the first time galaxies had a major impact on their surroundings.  Measuring a detailed timeline of this process can thus inform us on the nature of these first galaxies.  While significant effort has gone into pinning down the exact timing of the end of reionization (z~5.5, ~1 Gyr after the Big Bang), little is known about its beginnings. However, we are about to undergo a revolution.  I will discuss results from our research group pushing the Hubble Space Telescope to its limits by discovering galaxies in the first ~0.5 Gyr after the Big Bang, studying their spatial abundances, physical properties, and effects on their surroundings.  I will then discuss two Cycle 1 James Webb Space Telescope programs which are primed to make significant progress.  First, the Cosmic Evolution Early Release Science (CEERS) Survey is now providing our first glimpse at even earlier times, and I will highlight several early results.  Second, the Next Generation Deep Exploratory Extragalactic Public (NGDEEP) Survey will provide JWST’s version of the famous Hubble Ultra Deep Field, potentially showing us the first generation of modestly-sized galaxies to form after the Big Bang.  The combination of these surveys is leading to a transformation in our understanding of the earliest phases of galaxy formation.

I study the processes by which galaxies evolve through time, from extremely small systems in the early universe, to form large galaxies today like our own Milky Way. I discover these galaxies using imaging from space telescopes. Members of my group and I study these images to both discover and characterize distant galaxies, and we use the largest ground-based telescopes to follow them up spectroscopically. I am also heavily involved in the HETDEX project, and we are working to build the next great extragalactic legacy field in a 24 square degree region of the HETDEX survey (the HETDEX/SHELA field) where we are amassing imaging from the optical to infrared from both ground and space-based telescopes. In the near future we will use data from the James Webb Space Telescope to push even closer to the Big Bang, using data from the CEERS and WDEEP programs to discover some of the earliest galaxies to form in the universe.


Meeting ID: 869 9126 6018
Passcode: 537391