Study of diffuse emission in cluster MACSJ0417.5-1154 from 76 MHz to 18 GHz

  • Pritpal Sandhu
  • Ramij RajaEmail author
  • Majidul Rahaman
  • Siddharth Malu
  • Abhirup Datta


We present new radio observations of the massive and X-ray luminous galaxy cluster MACS J0417.5–1154, at 1.387 GHz and 18 GHz, from the Giant Metrewave Radio Telescope (GMRT) and the Australia Telescope Compact Array (ATCA) respectively. We estimate diffuse emission in the central region of the cluster at 1.387 GHz and 18 GHz. We combine these data with previously published results and present the spectrum of diffuse emission from 76 MHz to 18 GHz. This is possibly a unique study of the radio halo emission in galaxy cluster over this wide range of frequencies. Such studies lay the prospects of future studies with radio telescopes with wide-range of frequencies like the Square Kilometre Array (SKA). Our 1.387 GHz data, with \(2^{\prime \prime }\) angular resolution, provides a better estimate of point source emission than previous L-band observations, which is crucial, given the claim of sharp steepening of the radio halo spectrum at 0.61 GHz reported earlier. We find that the spectrum of the radio halo has a spectral index fit up to 18 GHz, and yields a spectral index between 76 MHz and 18 GHz that fits the available data better than earlier L-band observations. We discuss possible reasons for the peculiar spectral characteristics of the diffuse emission.


Galaxies clusters individual (MACS J0417.5-1154) intergalactic medium radio continuum general techniques interferometric 



We thank the staff of the GMRT and ATCA who have made these observations possible. GMRT is run by the National Centre for Radio Astrophysics of the Tata Institute of Fundamental Research. ATCA is part of the Australia Telescope which is funded by the Commonwealth of Australia for operation as a National Facility managed by CSIRO. We thank Nirupam Roy for discussion and suggestions in the L-Band GMRT data reduction. Analysis of radio data was made possible by a generous grant for Astronomy by IIT Indore.


  1. Blasi P., Colafrancesco S. 1999, APh, 12, 169ADSGoogle Scholar
  2. Brown S., Emerick A., Rudnick L., Brunetti G. 2011, ApJ, 740, L28ADSGoogle Scholar
  3. Brunetti G., Setti G., Feretti L., Giovannini G. 2001, MNRAS, 320, 365ADSGoogle Scholar
  4. Brunetti G., Jones T. W. 2014, IJMPD, 23, 1430007-98ADSGoogle Scholar
  5. Brunetti G., Cassano R., Dolag K., Setti G. 2009, A&A, 507, 661ADSGoogle Scholar
  6. Dennison B. 1980, ApJ, 239, L93ADSGoogle Scholar
  7. Dwarakanath K. S., Malu S., Kale R. 2011, JApA, 32, 529ADSGoogle Scholar
  8. Ebeling H., Edge A. C., Mantz A., Barrett E., Henry J. P., Ma C. J., van Speybroeck L. 2010, MNRAS, 407, 83ADSGoogle Scholar
  9. Feretti L., Giovannini G., Govoni F., Murgia M. 2012, A&ARv, 20, 54ADSGoogle Scholar
  10. Hurley-Walker, N., et al. 2017, MNRAS 464, 1146ADSGoogle Scholar
  11. Intema H. T., van der Tol S., Cotton W. D., Cohen A. S., van Bemmel I. M., Röttgering H. J. A. 2009, A&A, 501, 1185ADSGoogle Scholar
  12. Intema H. T., Jagannathan P., Mooley K. P., Frail D. A. 2017, A&A, 598, A78ADSGoogle Scholar
  13. Mohan N., Rafferty D. 2015, ascl.soft, ascl:1502.007Google Scholar
  14. Parekh V., Dwarakanath K. S., Kale R., Intema H. 2017, MNRAS, 464, 2752ADSGoogle Scholar
  15. Petrosian V. 2001, ApJ, 557, 560ADSGoogle Scholar
  16. Sandhu P., Malu S., Raja R., Datta A. 2018, Ap&SS, 361, 8Google Scholar
  17. Scaife A. M. M., Heald G. H. 2012, MNRAS, 423, L30ADSGoogle Scholar
  18. Skillman, S. W., Xu, H., Hallman, E. J., et al. 2013, ApJ, 765, 21ADSGoogle Scholar
  19. Venturi T., Giacintucci S., Dallacasa D., Cassano R., Brunetti G., Bardelli S., Setti G. 2008, A&A, 484, 327ADSGoogle Scholar
  20. Wilson W. E., et al. 2011, MNRAS, 416, 832ADSGoogle Scholar

Copyright information

© Indian Academy of Sciences 2019

Authors and Affiliations

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

Personalised recommendations