skip to main content

Title: The kinetic Sunyaev-Zel'dovich effect from the diffuse gas in the Local Group

Since the Local Group (LG) of galaxies moves with a bulk velocity with respect to the cosmic microwave background radiation (CMB), free electrons in its gaseous halo should imprint large-scale non-primordial temperature shifts in the CMB via the kinetic Sunyaev-Zel'dovich (kSZ) effect. By modeling the distribution of gas in the LG halo and using its inferred velocity with respect to the CMB, we calculate the resulting kSZ signal from the diffuse LG medium. We find that it is dominated by a hot spot ∼ 10° in size in the direction of M31, where the optical depth of free electrons is the greatest. By performing a correlation analysis, we find no statistical evidence that the kSZ signal from model of the LG halo is embedded in the CMB temperature map measured by the Planck satellite. We constrain the amount of mass in the LG halo by limiting the kSZ temperature shift around the hot spot to be smaller than the observed temperature shift in the Planck map. We find the tightest constraints for models where the halo mass is highly concentrated, with the mass limited to roughly 2.5–5 × 10{sup 12}M{sub ⊙}, but note that halos with such high concentrations aremore » rare.« less
Authors:
 [1] ;  [2]
  1. Department of Physics, Harvard University, Cambridge, MA, 02138 (United States)
  2. Department of Astronomy, Harvard University, Cambridge, MA, 02138 (United States)
Publication Date:
OSTI Identifier:
22369786
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Cosmology and Astroparticle Physics; Journal Volume: 2014; Journal Issue: 01; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; CONCENTRATION RATIO; CORRELATIONS; DEPTH; DISTRIBUTION; ELECTRONS; GALAXIES; HOT SPOTS; MASS; RELICT RADIATION; SATELLITES; SIGNALS; SIMULATION; VELOCITY