Full-sky map of the ISW and Rees-Sciama effect from Gpc simulations

• DOI: 10.1111/j.1365-2966.2010.16946.x
• Publication Date: 2010-06-17T04:31:12Z
• Authors: Yan-Chuan Cai; Shaun Cole; Adrian Jenkins; Carlos S. Frenk
• Keywords: Cold dark matter; Cosmic background radiation

We present a new method for constructing maps of the secondary temperature fluctuations imprinted on cosmic microwave background (CMB) radiation by photons propagating through evolving gravitational potential. Large cosmological N-body simulations are used to calculate complete non-linear evolution peculiar Tracing light rays back past cone chosen observer accurately captures perturbations generated linear (the integrated Sachs–Wolfe or ISW effect) and Rees–Sciama RS evolution. These effects give rise three kinds features in maps. (i) In overdense regions, converging flows matter induce cold spots order 100 Mpc extent which can dominate over effect at high redshift, surrounded hot rings. (ii) underdense enhances be weak (iii) Transverse motions large lumps produce characteristic dipole features, consisting adjacent separated few tens megaparsecs. not easily detectable; they modulate sky about 10 per cent level. The causes angular power spectrum deviate from theory l∼ 50 generates non-Gaussianity, skewing one-point distribution function negative values. Cold similar size, but much smaller amplitude than CMB spot reported Cruz et al. produced. Joint analysis our corresponding galaxy may enable techniques developed detect these non-linear, non-Gaussian features. Our available http://astro.dur.ac.uk/~cai/ISW.