GBT26B-169

Does Entropy Always Increase? Maybe Not in Cluster Cores

Abstract

Cool, low-entropy cores in galaxy clusters are thought to arise from a long-standing balance between radiative cooling and AGN feedback. While this phenomenon is well-established in the local universe, its connection at high redshift remains uncertain. We propose GBT/MUSTANG-2 observations of high-redshift clusters with existing deep X-ray data, completing a 13-cluster sample. The GBT/MUSTANG-2 data will provide high-resolution measurements of the Sunyaev-Zeldovich effect which, when combined with X-ray surface brightness maps, will yield spatially resolved temperature and entropy distributions. With these data, we will (1) search for cool, low-entropy cores in the intracluster medium at high redshift, and (2) test whether AGN feedback balances radiative cooling at early cosmic times. Using auxiliary LOFAR data, we will also search for AGN-driven outflows and measure the cooling-to-feedback power ratio (Pcav / Lcool) in systems with active jets. Together, these results will directly test whether feedback-regulated core structure is already in place at high redshift.

Investigators

Name	Institution
Joshiwa van Marrewijk *	Leiden, University of
Luca Di Mascolo	Kapteyn Astronomical Institute; Max-Planck-Institut für Astrophysik; Trieste, Università degli Studi di
Tony Mroczkowski	Institut de Ciències de l'Espai
John Orlowski-Scherer	Pennsylvania, University of; McGill University
Simon Dicker	Pennsylvania, University of
Brian Mason	National Radio Astronomy Observatory
Charles Romero	Pennsylvania, University of; Virginia, University of; Center for Astrophysics | Harvard & Smithsonian
Saianeesh Haridas	Pennsylvania, University of
Emily Moravec	Green Bank Observatory
IAN LOWE	Arizona, University of; Pennsylvania, University of
Giovanni Isopi	Roma La Sapienza, Università degli Studi di
Eleonora Barbavara	Roma La Sapienza, Università degli Studi di
Jonathan Sievers	Toronto, University of; McGill University; Princeton University; KwaZulu-Natal, University of
Anthony Flores	Rutgers, The State University of New Jersey
Cristobal Sifon	Princeton University; Valparaíso, Pontificia Universidad Católica de
Matt Hilton	KwaZulu-Natal, University of; Witwatersrand, University of the
Craig Sarazin	Virginia, University of
Mark Devlin	Pennsylvania, University of
John Hughes	Rutgers, The State University of New Jersey

* indicates the PI