2003/03/14 by Mikhail V. Medvedev, Medvedev, Mikhail V., Adrian L. Melott +7
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics (astro-ph) #FOS: Physical sciences #Galaxies: Formation, Evolution, Phenomena #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/0303310
7 pages, 1 figure
arxiv created 2003/03/14 · openalex publication_date 2003/03/14 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We have calculated lower limits for the global effective thermal conductivity in a sample of 165 Abell clusters. We assumed that cluster X-ray luminosity is compensated by a conductive heat flux which we then compare with an upper limit to the temperature gradient inferred from the cluster temperature and radius. This gives a lower limit to the thermal conductivity and therefore to the relative suppression from the Spitzer conductivity, kappaSp. Not a single cluster requires super-Spitzer values of thermal conduction to balance the observed X-ray luminosity. The suppression coefficient f=kappa/kappaSp is clustered in a range 10-2 < f < 0.4. A weak dependence of f versus z is observed over 0 < z <0.41. Possible biases and/or selection effects are discussed.