Collaborative Research: Tracing Cosmic Structures with Galaxies, Quasars, and Gas at Cosmic Noon

Galaxies come in wide variety of shapes, from great star-forming spirals like our own Milky Way galaxy to the red-and-dead elliptical-type systems. For some time, astronomers have known that this diversity is largely driven by environment, with galaxies in dense regions evolving differently from those in low-density voids. To understand this diversity we must look ~10 billion years into the past and survey large swaths of the universe at “cosmic noon”, when the universe was only ~1/4 its present size, star-formation and black hole activity peaked, and the great cosmic structures we see today were just beginning to form. By characterizing the galaxies' 3D environments, the team will quantify the relationships between a galaxy’s physical properties, such as its elemental composition, gas and dust content, stellar mass, and star-formation rate, with its environment. The team will also participate in a series of local education and outreach activities in Pennsylvania and Indiana, with a particular focus on engaging students in grades 4-12 to spark their interest in science. This program is aimed at elucidating how galaxies, quasars, and gas trace the cosmic structures of the 2 < z < 4 universe, and likewise, how dense environments within the large-scale structure influence their evolution. To do this, the program will combine the data products of three large surveys: imaging from the One-hundred-square-degree DECam Imaging In Narrowbands (ODIN) survey, wide-field integral-field spectroscopy of the Hobby-Eberly Telescope Dark Energy eXperiment and targeted spectroscopy from the Dark Energy Spectroscopic Instrument of up to several hundred thousand Lya-emitting galaxies at cosmic noon, residing in a wide range of large-scale environments. This unprecedented dataset will (i) confirm ODIN-detected cosmic structures and reconstruct the 3D shape of tens of massive protoclusters; (ii) identify rare astrophysical sources such as Ly-alpha blobs and active galactic nuclei (including quasars), in order to investigate their locations within the large-scale structure; (iii) infer the mean physical properties of galaxies as a function of large-scale environment based on their photometric and spectroscopic measurements; and (iv) study how intergalactic gas and galaxies trace the underlying matter distribution and each other. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.