MIT Astrophysics Colloquium 3/14/2023 — Via Zoom Only! Galaxies In The Distant Universe Are Now Much Closer Than Before: Early Results From JWST (speaker: Michael Maseda, University Of Wisconsin-Madison)
Tuesday March 14, 2023 4:00 pm
Please note: Due to MIT’s weather-related closure starting at 3pm, today’s astrophysics colloquium will be by zoom only.
Everyone on the MKIemail@example.com mailing list already has the zoom link.
Already in the first 8 months of science operations, JWST has begun to routinely detect and characterize the physical properties of galaxies with greater fidelity and at greater distances than were ever possible before. For example, in the JWST Advanced Deep Extragalactic Survey (JADES) we have not only identified numerous z > 10 galaxies, but we have obtained spectroscopic confirmations that paint a far more detailed picture than is possible from photometry alone. I will highlight some of the key early science results from JADES as well as a number of public observing programs, such as constraints on the production and escape of ionizing photons from galaxies in the Epoch of Reionization and the evolution in scaling relations such as galaxy stellar mass versus metallicity across cosmic time. I will furthermore discuss how these results may inform future work with JWST in Cycle 2 and beyond. Additionally, I will present some of the technical challenges that these new and unique data present, particularly in the context of NIRSpec multi-object spectroscopy. In sum, the prospects for future studies of galaxy evolution with JWST are extremely bright.
Host: Rohan Naidu
Image caption: The Webb Advanced Deep Extragalactic Survey (JADES) focused on the area in and around the Hubble Space Telescope’s Ultra Deep Field. Using Webb’s NIRCam instrument, scientists observed the field in nine different infrared wavelength ranges. From these images (shown at left), the team searched for faint galaxies that are visible in the infrared but whose spectra abruptly cut off at a critical wavelength known as the Lyman break. Webb’s NIRSpec instrument then yielded a precise measurement of each galaxy’s redshift (shown at right). Four of the galaxies studied are particularly special, as they were revealed to be at an unprecedentedly early epoch. These galaxies date back to less than 400 million years after the big bang, when the universe was only 2% of its current age. In the background image blue represents light at 1.15 microns (115W), green is 2.0 microns (200W), and red is 4.44 microns (444W). In the cutout images blue is a combination of 0.9 and 1.15 microns (090W+115W), green is 1.5 and 2.0 microns (150W+200W), and red is 2.0, 2.77, and 4.44 microns (200W+277W+444W).
Image Credit: NASA, ESA, CSA, and STScI, M. Zamani (ESA/Webb), L. Hustak (STScI). Science: B. Robertson (UCSC), S. Tacchella (Cambridge), E. Curtis-Lake (Hertfordshire), S. Carniani (Scuola Normale Superiore), and the JADES Collaboration