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Title: Sliding not sloshing in A3744: The influence of radio galaxies NGC 7018 and 7016 on cluster gas

We present new X-ray (Chandra) and radio (JVLA) observations of the nearby cluster A3744. It hosts two prominent radio galaxies with powers in the range critical for radio-mode feedback. The radio emission from these galaxies terminates in buoyant tendrils reaching the cluster's outer edge, and the radio-emitting plasma clearly influences the cluster's X-ray-emitting atmosphere. The cluster's average gas temperature, of kT = 3.5 keV, is high for its bolometric luminosity of 3.2 × 10{sup 43} erg s{sup –1}, but the 100 kpc-scale cavity carved out by radio-emitting plasma shows evidence of less than 2% of the excess enthalpy. We suggest instead that a high-velocity encounter with a galaxy group is responsible for dispersing and increasing the entropy of the gas in this non-cool-core cluster. We see no evidence for shocks, or established isobaric gas motions (sloshing), but there is much sub-structure associated with a dynamically active central region that encompasses the brightest radio emission. Gas heating is evident in directions perpendicular to the inferred line of encounter between the infalling group and cluster. The radio-emitting tendrils run along boundaries between gas of different temperature, apparently lubricating the gas flows and inhibiting heat transfer. The first stages of the encounter maymore » have helped trigger the radio galaxies into their current phase of activity, where we see X-rays from the nuclei, jets, and hotspots.« less
Authors:
;  [1]
  1. HH Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL (United Kingdom)
Publication Date:
OSTI Identifier:
22351501
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 784; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ATMOSPHERES; BOLOMETERS; EMISSION; ENTHALPY; ENTROPY; FEEDBACK; GALAXY CLUSTERS; GAS FLOW; HEAT TRANSFER; LUMINOSITY; PLASMA; RADIO GALAXIES; VELOCITY; X RADIATION; X-RAY GALAXIES