Astrophysics and Space Science

, 361:255

First detection at 5.5 and 9 GHz of the radio relics in bullet cluster with ATCA

Original Article


We present here results from observations at 5.5 and 9 GHz of the Bullet cluster 1E 0657–55.8 with the Australia Telescope Compact Array (ATCA). Our results show detection of diffuse emission in the cluster. Our findings are consistent with the previous observations by Shimwell et al. (2014, 2015) at 1.1–3.1 GHz. Morphology of diffuse structures (relic regions A and B and the radio halo) are consistent with those reported by the previous study. Our results indicate steepening in the spectral index at higher frequencies (\(\gtrsim5.0~\mbox{GHz}\)) for region A. The spectrum can be fit well by a broken power law. We discuss the possibility of a few recent theoretical models explaining this break in the power law spectrum, and find that a modified Diffusive Shock Acceleration (DSA) model or a turbulent reacceleration model may be relevant. Deep radio observations at high frequencies (\(\gtrsim5~\mbox{GHz}\)) are required for a detailed comparison with this model.


Cosmic microwave background Galaxies: clusters: individual (1E 0657–56, RX J0658–5557) Intergalactic medium Radio continuum: general Techniques: interferometric 

Copyright information

© Springer Science+Business Media Dordrecht 2016

Authors and Affiliations

  1. 1.Centre of AstronomyIndian Institute of Technology IndoreIndoreIndia
  2. 2.Center for Astrophysics and Space Astronomy, Department of Astrophysical and Planetary ScienceUniversity of ColoradoBoulderUSA
  3. 3.Physics DepartmentIndian Institute of Technology IndoreIndoreIndia

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