Chandra observation of two shock fronts in the merging galaxy cluster Abell 2146

2010/04/09 by H. R. Russell, J. S. Sanders, A. C. Fabian +8 · 2 citations
Physics and Astronomy · #Abell 2744 #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Astrophysics and Star Formation Studies #Atmospheric sciences #Brightest cluster galaxy #Cluster (spacecraft) #Cold front #Galaxies: Formation, Evolution, Phenomena #Galaxy #Galaxy cluster #Mach number #Physics #Ram pressure #Shock (circulatory) #Shock front #Shock wave #Star formation #astro-ph.CO

paper · pdf · doi:10.1111/j.1365-2966.2010.16822.x

13 pages, 13 figures, accepted by MNRAS

arxiv created 2010/04/09 · openalex publication_date 2010/05/01 · arxiv updated 2010/08/23 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05

Abstract

We present a new Chandra observation of the galaxy cluster Abell 2146 which has revealed a complex merging system with a gas structure that is remarkably similar to the Bullet cluster. The X-ray image and temperature map show a cool 2 –3 keV subcluster with a ram pressure stripped tail of gas just exiting the disrupted 6 − 7 keV primary cluster. From the sharp jump in the temperature and density of the gas, we determine that the subcluster is preceded by a bow shock with a Mach number M= 2.2 ± 0.8, corresponding to a velocity v= 2200+1000−900 km s−1 relative to the main cluster. We estimate that the subcluster passed through the primary core only 0.1 –0.3 Gyr ago. In addition, we observe a slower upstream shock propagating through the outer region of the primary cluster and calculate a Mach number M= 1.7 ± 0.3. Based on the measured shock Mach numbers M∼ 2 and the strength of the upstream shock, we argue that the mass ratio between the two merging clusters is between 3 and 4 to one. By comparing the Chandra observation with an archival Hubble Space Telescope observation, we find that a group of galaxies is located in front of the X-ray subcluster core but the brightest cluster galaxy is located immediately behind the X-ray peak.

Citations

• Confirmation of the Presence of Nonthermal Hard X-Ray Excess in the Cluster A2256 from Two Epoch Observations
• GMRT radio halo survey in galaxy clusters atz= 0.2–0.4
• On the evolution of giant radio halos and their connection with cluster mergers
• Direct X-ray spectral deprojection of galaxy clusters
• Direct Constraints on the Dark Matter Self‐Interaction Cross Section from the Merging Galaxy Cluster 1E 0657−56
• AnXMM-Newtonobservation of the dynamically active binary cluster A1750
• Chandrameasurements of non-thermal-like X-ray emission from massive, merging, radio halo clusters
• A Wavelet‐Based Algorithm for the Spatial Analysis of Poisson Data
• Particle acceleration at astrophysical shocks: A theory of cosmic ray origin
• The impact of mergers on relaxed X-ray clusters – I. Dynamical evolution and emergent transient structures
• The Origin of Cold Fronts in the Cores of Relaxed Galaxy Clusters
• A direct empirical proof of the existence of dark matter
• A Textbook Example of a Bow Shock in the Merging Galaxy Cluster 1E 0657-56

Cited by

• Astrophysical and cosmological probes of dark matter
• Evidence for a Merger-induced Shock Wave in ZwCl 0008.8+5215 with Chandra and Suzaku

Related

• A rare, strong shock front in the merging cluster SPT-CL J2031-4037
• A new shock in the pre-merging cluster pair 1E2215-2216
• Forming one of the most massive objects in the Universe: The quadruple merger in Abell 1758
• Chandra observations of the Abell S0295 cluster
• Chandra observation of the most interesting cluster in the Universe