MUSTANG and MUSTANG 1.5: High-Resolution Measurements of the Sunyaev-Zel'dovich Effect in Galaxy Clusters
Abstract
High-resolution GBT+MUSTANG observations of the Sunyaev-Zel'dovich Effect (SZE) at 90GHz have revealed complex substructure in the hot intra-cluster medium (ICM) of several massive galaxy clusters. The SZE is a nearly redshift-independent, complementary probe of the ICM to X-ray emission and combined analyses of both data sets provide a better understanding of astrophysical phenomena such as shocks, cold fronts, and sloshing of the gas within a cluster's dark matter potential. Understanding how substructure, especially in merging clusters, affects the scaling between SZE flux and total cluster mass is essential to placing tight constraints on cosmological parameters with SZE surveys. First, I will present recent results from MUSTANG observations of the SZE in MACS J0647.7+7015 and MACS J1206.2-0847. In order to better characterize the cluster dynamics, a number of models are jointly fit in the map domain using a least squares fitting routine. We compare our data to the best-fit generalized Navarro, Frenk, and White (gNFW) profiles from Bolocam and find evidence for a steeper central slope in both clusters than had previously been determined. Furthermore, MUSTANG detects significant features near the core of both clusters that are suggestive of substructure. High-resolution SZE measurements out to larger angular scales will be necessary to better understand the nature of features like these. With this in mind, we are building MUSTANG-1.5, a new bolometer camera which offers many advantages over MUSTANG and unlocks SZE's true potential as an independent tool to understand the ICM on a broad range of angular scales and with a noise level better than any current instrument. I will present a status report on the progress of the receiver, which we aim to install on the Green Bank Telescope (GBT) for first light this season. The improvement in sensitivity and much larger field-of-view (3.5' compared to 35" for MUSTANG) will enable us to pursue a far more comprehensive observing program including the first ever detection of X-ray cavities via the SZE and high-resolution measurements of the ICM out to unprecedented radii.
- Publication:
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American Astronomical Society Meeting Abstracts #223
- Pub Date:
- January 2014
- Bibcode:
- 2014AAS...22320802Y