ABSTRACT
Our standard cosmological model predicts that most of the matter in the universe is distributed into a network of filaments - the Cosmic Web - in which galaxies form and evolve. Because most of this material is too diffuse to form stars, its direct detection in emission has remained elusive for several decades leaving fundamental questions still open, including: How are galaxies linked to each other? What are the morphological, physical and kinematical properties of the Cosmic Web and Circumgalactic gas on both large and small scales? How do they affect galaxy formation and evolution? During the last few years we have been able to start addressing these questions in a completely new way: i.e., by directly detecting intergalactic gas in emission thanks to “cosmic flashlights” such as quasars which can ionise and thus light-up through fluorescent emission cosmic gas over large volumes. Recent surveys exploiting the capabilities of new instruments such MUSE and KCWI are now providing a large statistical sample of three-dimensional images of rest-frame-UV line emission from “cold” gas haloes (and sometimes filaments) around galaxies, which are ubiquitously detected in the surrounding of quasars at all explored redshifts (2<z<6.5). In this talk, I will review these exciting results and discuss how they can provide new learning opportunities for our understanding of the physical properties of gas around massive galaxies and high-redshift galaxy formation. In particular, I will present ongoing deep and wide follow-up studies on some quasar fields which are revealing the Cosmic Web distribution on Mpc-scales and discuss how these multi-wavelength surveys using ALMA, JWST, Chandra, HST and ground-based imaging are opening up a new window on the study of galaxy and structure formation.
BIO
Dr. Sebastiano Cantalupo is a Professor of Astrophysics at the University of Milan Bicocca and, until August 2021, a Swiss National Science Foundation Professor at ETH Zurich. Before his current appointments, he was a Postdoctoral Fellow at the University of California Santa Cruz and a Postdoctoral Research Associate at the Institute of Astronomy, Cambridge. He devotes his main research efforts to make the "dark" Universe and its filamentary network that we call the "Cosmic Web" visible to our optical telescopes using both numerical simulation and observations with the most advanced astronomical instruments on 8-10m class telescopes. To know more information about Dr. Sebastiano Cantalupo, please refer to http://cosmib.org/cantalupo/
Host: Dandan Xu
