How Much can we Learn from a Merging Cold Front Cluster? Insights from X-Ray Temperature and Radio Maps of A3667
Abstract
The galaxy cluster A3667 is an ideal laboratory to study the plasma processes in the intracluster medium. High-resolution Chandra X-ray observations show a cold front in A3667. At radio wavelengths, A3667 reveals a double radio-relic feature in the outskirts of the cluster. These suggest multiple merger events in this cluster. In this paper, we analyze the substantial archival X-ray observations of A3667 from the Chandra X-ray Observatory and compare these with existing radio observations as well as state-of-the-art adaptive mesh refinement MHD cosmological simulations using Enzo. We have used two temperature map making techniques, weighted Voronoi tessellation and adaptive circular binning, to produce the high-resolution and largest field-of-view temperature maps of A3667. These high-fidelity temperature maps allow us to study the X-ray shocks in the cluster using a new two-dimensional shock-finding algorithm. We have also estimated the Mach numbers from the shocks inferred from previous ATCA radio observations. The combined shock statistics from the X-ray and radio data are in agreement with the shock statistics in a simulated MHD cluster. We have also studied the profiles of the thermodynamic properties across the cold front using ~447 ks from the combined Chandra observations on A3667. Our results show that the stability of the cold front in A3667 can be attributed to the suppression of the thermal conduction across the cold front by a factor of ~100-700 compared to the classical Spitzer value.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- October 2014
- DOI:
- 10.1088/0004-637X/793/2/80
- arXiv:
- arXiv:1408.5123
- Bibcode:
- 2014ApJ...793...80D
- Keywords:
-
- galaxies: abundances;
- galaxies: clusters: general;
- radiation mechanisms: non-thermal;
- radiation mechanisms: thermal;
- X-rays: galaxies: clusters;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- 23 pages, 16 figures. Accepted for publication in The Astrophysical Journal