Caltech Astronomy Public Lecture Series - Mapping the Universe - Guochao Sun - 02/04/2022

What does the early universe look like, prior to the formation of the first stars and galaxies? How can we map the structure of the universe prior to the advent of stars and starlight itself? Join us to learn these answers and more at a night of astronomy! Timestamps below: 00:00 Announcements 04:44 Intro to Mapping the Universe Presentation 05:18 Mapping the Universe Presentation 35:27 Intro to Q&A Panel 39:48 How does a supermassive black hole cause stars to form? 45:27 What factors determine the star formation rate of galaxies? 50:01 Are there magnetic fields everywhere? 53:25 Is there evidence that the universe has net-neutral charge? 57:50 What can we learn from line intensity mapping? 1:00:18 What will the universe look like in the future? 1:04:03 What will JWST investigate about interstellar gas? 1:07:51 What fringe science are astronomers engaged in today? 1:16:56 Is the universe infinite? 1:19:35 Why are Fast Radio Bursts only affected by free electrons? 1:23:39 Why don't we see radiation from before the CMB? 1:29:43 Relationship between time, redshift, and mass 1:37:31 Have x-rays been observed redshifted into visible photons? 1:41:37 Does dark matter really exist or should the theory change? 1:49:17 Can the universe expand in more than 3 dimensions? 1:55:29 How can we distinguish cosmic microwave background photons from other radiation? 1:57:53 Concluding Remarks Title: Mapping the Universe with Atoms and Molecules that Shine Lecturer: Guochao (Jason) Sun Abstract: Since the beginning, people have wondered about the structure of the universe around us. Studying the starlight from millions of observed galaxies, astronomers are assembling an increasingly detailed picture of our universe, from the present to the distant past. In this lecture, I will describe a novel tool that allows astronomers to map the universe in a complementary manner to starlight: by measuring the light emitted from the cosmic gas, composed of atoms and molecules, that permeates our universe. Using this technique, astronomers are now peeking into the still mysterious chapters of our cosmic history, such as the infant universe when the first stars and galaxies formed. Participants: Guochao (Jason) Sun is a finishing PhD student working in the Observational Cosmology group at Caltech. He has a broad interest in topics at the interface between observational cosmology and theoretical astrophysics, in particular high-redshift universe and cosmic reionization. He enjoys reading, cooking, hiking and building Legos. https://www.guochaojasonsun.me Sarah Blunt is a third-year PhD student at Caltech. She’s interested in the orbits and atmospheres of exoplanets (planets orbiting other stars). She likes running, singing and playing cello, and hanging out with her pet dog Fido. https://sites.google.com/g.harvard.edu/sarah Dr. Gina Panopoulou is a postdoctoral researcher in Astrophysics at Caltech. She uses telescopes around the world and in space to study the ‘stuff that makes stars’, known as the interstellar medium. She enjoys stargazing, hiking, and trying out new recipes. https://www.its.caltech.edu/~panopg/ Dr. Cameron Hummels is a postdoctoral researcher in theoretical astrophysics at Caltech. He creates supercomputer simulations to study the formation and evolution of galaxies since the Big Bang. In addition to astrophysics and public education, he is really enthusiastic about trail-running, long-distance backpacking, brewing, chess, and the astronaut program. http://chummels.org