Implications of a High Angular Resolution Image of the Sunyaev-Zel'dovich Effect in RXJ1347-1145

TL;DR

This paper presents the highest resolution image of the Sunyaev-Zel'dovich Effect in galaxy cluster RXJ1347-1145, revealing shock-heated gas and pressure asymmetries that support a merger scenario.

Contribution

It provides the first high-resolution 90 GHz SZE image of RXJ1347-1145, confirming localized enhancement and asymmetry linked to a merger event.

Findings

Detection of a strong, localized SZE enhancement southeast of the cluster center.

Observation of a pressure asymmetry with a 1.6 times higher pressure east of the core.

Confirmation of shock-heated gas due to a major merger.

Abstract

The most X-ray luminous cluster known, RXJ1347-1145 (z=0.45), has been the object of extensive study across the electromagnetic spectrum. We have imaged the Sunyaev-Zel'dovich Effect (SZE) at 90 GHz (3.3 mm) in RXJ1347-1145 at 10" resolution with the 64-pixel MUSTANG bolometer array on the Green Bank Telescope (GBT), confirming a previously reported strong, localized enhancement of the SZE 20" to the South-East of the center of X-ray emission. This enhancement of the SZE has been interpreted as shock-heated (> 20 keV) gas caused by an ongoing major (low mass-ratio) merger event. Our data support this interpretation. We also detect a pronounced asymmetry in the projected cluster pressure profile, with the pressure just east of the cluster core ~1.6 times higher than just to the west. This is the highest resolution image of the SZE made to date.