Browsing by Author "Clowe, D. I."

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The Distribution of Dark and Luminous Matter in the Unique Galaxy Cluster Merger Abell 2146
(Oxford University Press) King, Lindsay J.; Clowe, D. I.; Coleman, Joseph E.; Russell, H. R.; Santana, R.; White, Jacob A.; Canning, R. E. A.; Deering, Nicole J.; Fabian, A. C.; Lee, Brandyn E.; Li, B.; McNamara, B. R.; 0000 0001 2437 3571 (King, LJ); 0000-0001-8445-0444 (White, JA); King, Lindsay J.; Clowe, D. I.; Coleman, Joseph E.; Russell, H. R.; Santana, R.; White, Jacob A.; Canning, R. E. A.; Deering, Nicole J.; Fabian, A. C.; Lee, Brandyn E.; Li, B.; McNamara, B. R.
Abell 2146 (z = 0.232) consists of two galaxy clusters undergoing a major merger. The system was discovered in previous work, where two large shock fronts were detected using the Chandra X-ray Observatory, consistent with a merger close to the plane of the sky, caught soon after first core passage. A weak gravitational lensing analysis of the total gravitating mass in the system, using the distorted shapes of distant galaxies seen with Advanced Camera for Surveys - Wide Field Channel on Hubble Space Telescope, is presented. The highest peak in the reconstruction of the projected mass is centred on the brightest cluster galaxy (BCG) in Abell 2146-A. The mass associated with Abell 2146-B is more extended. Bootstrapped noise mass reconstructions show the mass peak in Abell 2146-A to be consistently centred on the BCG. Previous work showed that BCG-A appears to lag behind an X-ray cool core; although the peak of the mass reconstruction is centred on the BCG, it is also consistent with the X-ray peak given the resolution of the weak lensing mass map. The best-fitting mass model with two components centred on the BCGs yields M200 = 1.1_{-0.4}^{+0.3} × 10¹⁵ and 3_{-2}^{+1} × 10¹⁴ M_⊙ for Abell 2146-A and Abell 2146-B, respectively, assuming a mass concentration parameter of c = 3.5 for each cluster. From the weak lensing analysis, Abell 2146-A is the primary halo component, and the origin of the apparent discrepancy with the X-ray analysis where Abell 2146-B is the primary halo is being assessed using simulations of the merger.
Dynamical Analysis of Galaxy Cluster Merger Abell 2146
(Oxford Univ Press, 2015-09-03) White, Jacob A.; Canning, R. E. A.; King, Lindsay J.; Lee, Brandyn E.; Russell, H. R.; Baum, S. A.; Clowe, D. I.; Coleman, Joseph E.; Donahue, M.; Edge, A. C.; Fabian, A. C.; Johnstone, R. M.; McNamara, B. R.; O'Dea, C. P.; Sanders, J. S.; White, Jacob A.; King, Lindsay J.; Lee, Brandyn E.; Coleman, Joseph E.
We present a dynamical analysis of the merging galaxy cluster system Abell 2146 using spectroscopy obtained with the Gemini Multi-Object Spectrograph on the Gemini North telescope. As revealed by the Chandra X-ray Observatory, the system is undergoing a major merger and has a gas structure indicative of a recent first core passage. The system presents two large shock fronts, making it unique amongst these rare systems. The hot gas structure indicates that the merger axis must be close to the plane of the sky and that the two merging clusters are relatively close in mass, from the observation of two shock fronts. Using 63 spectroscopically determined cluster members, we apply various statistical tests to establish the presence of two distinct massive structures. With the caveat that the system has recently undergone a major merger, the virial mass estimate is M_{vir} = 8.5_{-4.7}^{+4.3} x 10¹⁴ M_⊙ for the whole system, consistent with the mass determination in a previous study using the Sunyaev-Zel'dovich signal. The newly calculated redshift for the system is z = 0.2323. A two-body dynamical model gives an angle of 13⁰-19⁰ between the merger axis and the plane of the sky, and a time-scale after first core passage of 0.24-0.28 Gyr.