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arXiv · 1903.05644

Understanding the circumgalactic medium is critical for understanding galaxy evolution

Abstract

Galaxies evolve under the influence of gas flows between their interstellar medium and their surrounding gaseous halos known as the circumgalactic medium (CGM). The CGM is a major reservoir of galactic baryons and metals, and plays a key role in the long cycles of accretion, feedback, and recycling of gas that drive star formation. In order to fully understand the physical processes at work within galaxies, it is therefore essential to have a firm understanding of the composition, structure, kinematics, thermodynamics, and evolution of the CGM. In this white paper we outline connections between the CGM and galactic star formation histories, internal kinematics, chemical evolution, quenching, satellite evolution, dark matter halo occupation, and the reionization of the larger-scale intergalactic medium in light of the advances that will be made on these topics in the 2020s. We argue that, in the next decade, fundamental progress on all of these major issues depends critically on improved empirical characterization and theoretical understanding of the CGM. In particular, we discuss how future advances in spatially-resolved CGM observations at high spectral resolution, broader characterization of the CGM across galaxy mass and redshift, and expected breakthroughs in cosmological hydrodynamic simulations will help resolve these major problems in galaxy evolution.

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Molly S. Peeples, Peter Behroozi, Rongmon Bordoloi, Alyson Brooks, James S. Bullock, Joseph N. Burchett, Hsiao-Wen Chen, John Chisholm, Charlotte Christensen, Alison Coil, Lauren Corlies, Aleksandar Diamond-Stanic, Megan Donahue, Claude-André Faucher-Giguère, Henry Ferguson, Drummond Fielding, Andrew J. Fox, David M. French, Steven R. Furlanetto, Mario Gennaro, Karoline M. Gilbert, Erika Hamden, Nimish Hathi, Matthew Hayes, Alaina Henry, J. Christopher Howk, Cameron Hummels, Dušan Kereš, Evan Kirby, Anton M. Koekemoer, Ting-Wen Lan, Lauranne Lanz, David R. Law, Nicolas Lehner, Jennifer M. Lotz, Crystal L. Martin, Kristen McQuinn, Matthew McQuinn, Ferah Munshi, S. Peng Oh, John M. O'Meara, Brian W. O'Shea, Camilla Pacifici, J. E. G. Peek, Marc Postman, Moire Prescott, Mary Putman, Eliot Quataert, Marc Rafelski, Joseph Ribaudo, Kate Rowlands, Kate Rubin, Brett Salmon, Claudia Scarlata, Alice E. Shapley, Raymond Simons, Gregory F. Snyder, Jonathan Stern, Allison L. Strom, Erik Tollerud, Paul Torrey, Grant Tremblay, Todd M. Tripp, Jason Tumlinson, Sarah Tuttle, Frank C. van den Bosch, G. Mark Voit, Q. Daniel Wang, Jessica K. Werk, Benjamin F. Williams, Dennis Zaritsky, Yong Zheng. 2019-03-13. Understanding the circumgalactic medium is critical for understanding galaxy evolution. https://arxiv.org/abs/1903.05644

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