C. S. Reynolds

Publications (2)0 Total impact

• Article: The nature of filamentary cold gas in the core of the Virgo Cluster

  N. Werner, J. B. R. Oonk, R. E. A. Canning, S. W. Allen, A. Simionescu, J. Kos, R. J. van Weeren, A. C. Edge, A. C. Fabian, A. von der Linden, P. E. J. Nulsen, C. S. Reynolds, M. Ruszkowski
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  ABSTRACT: We present a multi-wavelength study of the emission-line nebulae located southeast of the nucleus of M87, the central dominant galaxy of the Virgo Cluster. We report the detection of far-infrared (FIR) [CII] line emission from the nebulae using observations made with Herschel PACS. The infrared line emission is extended and cospatial with optical H{\alpha}+[NII], far-ultraviolet CIV lines, and soft X-ray emission. The filamentary nebulae evidently contain multi-phase material spanning a temperature range of at least 5 orders of magnitude, from ~100 K to ~10^7 K. This material has most likely been uplifted by the AGN from the center of M87. The thermal pressure of the 10^4 K phase appears to be significantly lower than that of the surrounding hot intra-cluster medium (ICM) indicating the presence of additional turbulent and magnetic pressure in the filaments. If the turbulence in the filaments is subsonic then the magnetic field strength required to balance the pressure of the surrounding ICM is B~30-70 {\mu}G. The spectral properties of the soft X-ray emission from the filaments indicate that it is due to thermal plasma with kT~0.5-1 keV, which is cooling by mixing with the cold gas and/or radiatively. Charge exchange can be ruled out as a significant source of soft X-rays. Both cooling and mixing scenarios predict gas with a range of temperatures. This is at first glance inconsistent with the apparent lack of X-ray emitting gas with kT<0.5 keV. However, we show that the missing very soft X-ray emission could be absorbed by the cold gas in the filaments with an integrated hydrogen column density of ~1.6x10^21 cm^-2, providing a natural explanation for the apparent temperature floor to the X-ray emission at kT~0.5 keV. The FIR through ultra-violet line emission is most likely primarily powered by the ICM particles penetrating the cold gas following a shearing induced mixing process.
  11/2012;
• Source

  Available from: ArXiv

  Article: A wide Chandra view of the core of the Perseus cluster

  A. C. Fabian, J. S. Sanders, S. W. Allen, R. E. A. Canning, E. Churazov, C. S. Crawford, W. Forman, J. GaBany, J. Hlavacek-Larrondo, R. M. Johnstone, H. R. Russell, C. S. Reynolds, P. Salome, G. B. Taylor, A. J. Young
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  ABSTRACT: We present new Chandra images of the X-ray emission from the core of the Perseus cluster of galaxies. The total observation time is now 1.4 Ms. New depressions in X-ray surface brightness are discovered to the north of NGC1275, which we interpret as old rising bubbles. They imply that bubbles are long-lived and do not readily breakup when rising in the hot cluster atmosphere. The existence of a 300 kpc long NNW-SSW bubble axis means there cannot be significant transverse large scale flows exceeding 100 km/s. Interesting spatial correlations are seen along that axis in early deep radio maps. A semi-circular cold front about 100 kpc west of the nucleus is seen. It separates an inner disturbed region dominated by the activity of the active nucleus of NGC1275 from the outer region where a subcluster merger dominates.
  05/2011;