GBT26A-317

Testing a CR-IC origin to the cooling flow problem with MUSTANG-2 and Chandra

Abstract

One of the most challenging unsolved problems in galaxy and AGN evolution is the cooling flow problem in cool core (CC) galaxy clusters, wherein the apparent rate gas cooling rate onto the central galaxy (inferred from X-rays) is much larger than observed star formation rates or cold gas reservoirs allow. Recently, we proposed that this problem could largely be alleviated if an additional X-ray continuum component were provided by the inverse-Compton scattering of cosmic ray leptons from a central AGN with the CMB, thus driving inflated X-ray measurements of gas cooling. The cleanest probe of this scenario is a predicted deficit of the SZ-derived pressure relative to X-rays within ~100 kpc of CC centers. We have performed a feasibility study with archival MUSTANG-2 and Chandra observations of ZwCl 3146, resulting in a ~5 sigma detection of such an SZ-to-X-ray pressure deficit. However, with a single object, we cannot rule out cluster orientation/elongation as a cause. Adequate SZ observations of additional clusters resolving the relevant physical scales do not exist, and MUSTANG-2 is the only viable facility to provide these observations. We propose MUSTANG-2 observations of three additional CC clusters to test this hypothesis with a representative CC cluster sample.

Investigators

Name	Institution
Emily Silich *	California Institute of Technology
Charles Romero	Pennsylvania, University of; Virginia, University of; Center for Astrophysics | Harvard & Smithsonian
Simon Dicker	Pennsylvania, University of
Emily Moravec	Green Bank Observatory
Tony Mroczkowski	Institut de Ciències de l'Espai
John Orlowski-Scherer	Pennsylvania, University of; McGill University
Saianeesh Haridas	Pennsylvania, University of
Eleonora Barbavara	Roma La Sapienza, Università degli Studi di
Luca Di Mascolo	Kapteyn Astronomical Institute; Max-Planck-Institut für Astrophysik; Trieste, Università degli Studi di
Joshiwa van Marrewijk	Leiden, University of
Brian Mason	National Radio Astronomy Observatory
IAN LOWE	Arizona, University of; Pennsylvania, University of
Giovanni Isopi	Roma La Sapienza, Università degli Studi di
Craig Sarazin	Virginia, University of
Jack Sayers	California Institute of Technology
Philip Hopkins	California Institute of Technology
Mark Devlin	Pennsylvania, University of
Jonathan Sievers	Toronto, University of; McGill University; Princeton University; KwaZulu-Natal, University of

* indicates the PI