Journal article

Modelling of the spectral energy distribution of Fornax A: leptonic and hadronic production of high-energy emission from the radio lobes

B McKinley, R Yang, M Lopez-Caniego, F Briggs, N Hurley-Walker, RB Wayth, AR Offringa, R Crocker, G Bernardi, P Procopio, BM Gaensler, SJ Tingay, M Johnston-Hollitt, M McDonald, M Bell, NDR Bhat, JD Bowman, RJ Cappallo, BE Corey, AA Deshpande Show all

Monthly Notices of the Royal Astronomical Society | OXFORD UNIV PRESS | Published : 2015


We present new low-frequency observations of the nearby radio galaxy Fornax A at 154MHz with the Murchison Widefield Array, microwave flux-density measurements obtained from WMAP and Planck data, and γ -ray flux densities obtained from Fermi data. We also compile a comprehensive list of previously published images and flux-density measurements at radio, microwave and X-ray energies. A detailed analysis of the spectrum of Fornax A between 154 and 1510MHz reveals that both radio lobes have a similar spatially averaged spectral index, and that there exists a steep-spectrum bridge of diffuse emission between the lobes. Taking the spectral index of both lobes to be the same, we model the spectral..

View full abstract


Awarded by U.S. National Science Foundation

Awarded by Australian Research Council (LIEF)

Awarded by U.S. Air Force Office of Scientific Research

Awarded by Centre for All-sky Astrophysics (an Australian Research Council Centre of Excellence)

Awarded by Victoria University of Wellington from the New Zealand Ministry of Economic Development

Awarded by Spanish MINECO

Funding Acknowledgements

This scientific work makes use of the Murchison Radio-astronomy Observatory, operated by CSIRO. We acknowledge the Wajarri Yamatji people as the traditional owners of the Observatory site. Support for the MWA comes from the U.S. National Science Foundation (grants AST-0457585, PHY-0835713, CAREER-0847753 and AST-0908884), the Australian Research Council (LIEF grants LE0775621 and LE0882938), the U.S. Air Force Office of Scientific Research (grant FA9550-0510247) and the Centre for All-sky Astrophysics (an Australian Research Council Centre of Excellence funded by grant CE110001020). Support is also provided by the Smithsonian Astrophysical Observatory, the MIT School of Science, the Raman Research Institute, the Australian National University and the Victoria University of Wellington (via grant MED-E1799 from the New Zealand Ministry of Economic Development and an IBM Shared University Research Grant). The Australian Federal government provides additional support via the Commonwealth Scientific and Industrial Research Organisation (CSIRO), National Collaborative Research Infrastructure Strategy, Education Investment Fund, and the Australia India Strategic Research Fund, and Astronomy Australia Limited, under contract to Curtin University. We acknowledge the iVEC Petabyte Data Store, the Initiative in Innovative Computing and the CUDA Center for Excellence sponsored by NVIDIA at Harvard University, and the International Centre for Radio Astronomy Research (ICRAR), a Joint Venture of Curtin University and The University of Western Australia, funded by the Western Australian State government. We acknowledge the support of the projects Spanish MINECO AYA2012-39475-C02-01 and CSD2010-00064. We would also like to thank the referee for their useful comments and suggestions.