Sample variance of non-Gaussian sky distributions

Abstract

view Abstract Citations (8) References (16) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Sample Variance of Non-Gaussian Sky Distributions Luo, Xiaochun Abstract Non-Gaussian distributions of cosmic microwave background (CMB) anisotropies have been proposed to reconcile the discrepancies between different experiments at half-degree scales (Coulson et al. 1994). Each experiment probes a different part of the sky, furthermore, sky coverage is very small, hence the sample variance of each experiment can be large, especially when the sky signal is non-Gaussian. We model the degree-scale CMB sky as a $\chi_{n}^{2}$ field with $n$-degrees of freedom and show that the sample variance is enhanced over that of a Gaussian distribution by a factor of $ {(n +6)/ n}$. The sample variance for different experiments are calculated, both for Gaussian and non-Gaussian distributions. We also show that if the distribution is highly non-Gaussian $(n \ltwid 4)$ at half-degree scales, then the non-Gaussian signature of the CMB could be detected in the FIRS map, though probably not in the COBE map. Publication: The Astrophysical Journal Pub Date: February 1995 DOI: 10.1086/175192 arXiv: arXiv:astro-ph/9404069 Bibcode: 1995ApJ...439..517L Keywords: Anisotropy; Background Radiation; Cosmology; Microwaves; Sky Surveys (Astronomy); Variance (Statistics); Cosmic Rays; Gauss Equation; Stochastic Processes; Temperature Measurement; Astrophysics; COSMOLOGY: COSMIC MICROWAVE BACKGROUND; COSMOLOGY: THEORY; Astrophysics E-Print: 10 pages, latex, CfPA-th-94-22 full text sources arXiv | ADS |