GBT25B-090

Understanding the Support Mechanism of X-ray Cavities in Abell 780

Abstract

Clusters of galaxies contain enormous reservoirs of gas, which should be available to fuel star formation. However, the expected large amounts of cool gas at the center of galaxy clusters are not observed, both directly through a paucity of soft X-ray emission and indirectly in depressed star formation rates. Feedback by AGN plays a prominent role in reheating the gas, but the exact mechanism by which they inject energy into the ICM is unknown. Sunyaev-Zeldovich observations of X-ray cavities can shed light on this mystery by probing the electron momentum distribution, which is tied to the underlying support mechanism. We propose observations of the largest pair of cavities in Abell 780. The cavities are among the most energetic known. Moreover, due to the closeness of Abell 780 (z~=0.05), they are very bright in the SZ. We propose Mustang-2 observations of these cavities, which will be able to elucidate their support mechanism. This work will build on Orlowski-Scherer 2022, which observed the cavities of MS0735 (AGBT21A_123 and AGBT19A_092) and found their support mechanism to most likely be non-thermal. Adding Abell 780 to this list would represent a significant step forward in understanding the mechanisms by which AGN couple to the ICM.

Investigators

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

* indicates the PI