A diffuse bubble-like radio-halo source MRC 0116+111: imprint of AGN feedback in a low-mass cluster of galaxies |
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Authors: | Joydeep Bagchi Joe Jacob Gopal-Krishna Norbert Werner Nitin Wadnerkar Jaydeep Belapure A C Kumbharkhane |
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Institution: | Inter University Center for Astronomy and Astrophysics (IUCAA), Post Bag 4, Ganeshkhind, Pune 411 007, India;Department of Physics, Newman College, Thodupuzha 685 585, India;National Center for Radio Astrophysics (NCRA-TIFR), Post Bag 3, Ganeshkhind, Pune 411 007, India;Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, 452 Lomita Mall, Stanford, CA 94305, USA;School of Physical Sciences, Swami Ramanand Teerth Marathwada University, Nanded 431 606, India;Department of Physics, Pune University, Pune 411 007, India |
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Abstract: | We present detailed observations of MRC 0116+111, revealing a luminous, miniradio halo of ~240-kpc diameter located at the centre of a cluster of galaxies at redshift z = 0.131 . Our optical and multiwavelength Giant Metrewave Radio Telescope and Very Large Array radio observations reveal a highly unusual radio source: showing a pair of giant (~100-kpc diameter) bubble-like diffuse structures, that are about three times larger than the analogous extended radio emission observed in M87 – the dominant central radio galaxy in the Virgo cluster. However, in MRC 0116+111 we do not detect any ongoing active galactic nucleus (AGN) activity, such as a compact core or active radio jets feeding the plasma bubbles. The radio emitting relativistic particles and magnetic fields were probably seeded in the past by a pair of radio jets originating in the AGN of the central cD galaxy. The extremely steep high-frequency radio spectrum of the north-western bubble, located ~100 kpc from cluster centre, indicates radiation losses, possibly because having detached, it is rising buoyantly and moving away into the putative hot intracluster medium. The other bubble, closer to the cluster centre, shows signs of ongoing particle re-acceleration. We estimate that the radio jets which inflated these two bubbles might have also fed enough energy into the intracluster medium to create an enormous system of cavities and shock fronts, and to drive a massive outflow from the AGN, which could counter-balance and even quench a cooling flow. Therefore, this source presents an excellent opportunity to understand the energetics and the dynamical evolution of radio jet inflated plasma bubbles in the hot cluster atmosphere. |
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Keywords: | acceleration of particles magnetic fields galaxies: active galaxies: clusters: individual: MRC 0116+111 radio continuum: general X-rays: galaxies: clusters |
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