Density and temperature of cosmic-web filaments on scales of tens of megaparsecs [CEA]

http://arxiv.org/abs/1911.09706


We study physical properties of matter in 23,950 filaments ranging from 30 to 100 Mpc length identified in the SDSS survey. We stack the Comptonization y map produced by the Planck Collaboration around the filaments, excluding all the resolved galaxy groups and clusters above the mass of 10^13 Msun. We detect for the first time the tSZ signal at a significance of 3.7 sigma in filamentary gas on such a large scale. We also stack the Planck CMB lensing convergence map in the same manner and detect the lensing signal at a significance of 7.1 sigma. To estimate physical properties of the matter, we consider an isothermal, cylindrical filament model with a density distribution following a beta-model (beta=2/3). Assuming that the gas distribution follows the dark matter distribution, the central gas and matter overdensity and gas temperature are estimated to be overdensity = (25.3 +34.6 -15.1) and temperature = (1.2 +- 0.4) * 10^6 K, which results in a measured baryon fraction of (0.071 +0.097 -0.042) * Omega_b.

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H. Tanimura, N. Aghanim, V. Bonjean, et. al.
Mon, 25 Nov 19
10/55

Comments: 11 pages, 9 figures, Submitted to A&A