Estimating the bispectrum of the Very Small Array data
Abstract
We estimate the bispectrum of the Very Small Array data from the compact and extended configuration observations released in December 2002, and compare our results to those obtained from Gaussian simulations. There is a slight excess of large bispectrum values for two individual fields, but this does not appear when the fields are combined. Given our expected level of residual point sources, we do not expect these to be the source of the discrepancy. Using the compact configuration data, we put an upper limit of 5400 on the value of f_NL, the non-linear coupling parameter, at 95 per cent confidence. We test our bispectrum estimator using non-Gaussian simulations with a known bispectrum, and recover the input values.
Cite
@article{arxiv.astro-ph/0401618,
title = {Estimating the bispectrum of the Very Small Array data},
author = {Sarah Smith and Graca Rocha and Anthony Challinor and Richard A. Battye and Pedro Carreira and Kieran Cleary and Rod D. Davies and Richard J. Davis and Clive Dickinson and Ricardo Genova-Santos and Keith Grainge and Carlos M. Gutierrez and Yaser A. Hafez and Michael P. Hobson and Michael E. Jones and Rudiger Kneissl and Katy Lancaster and Anthony Lasenby and J. P. Leahy and Klaus Maisinger and Guy G. Pooley and Nutan Rajguru and Rafael Rebolo and Jose Alberto Rubino-Martin and Pedro Sosa Molina and Richard D. E. Saunders and Richard S. Savage and Paul Scott and Anze Slosar and Angela C. Taylor and David Titterington and Elizabeth Waldram and Robert A. Watson},
journal= {arXiv preprint arXiv:astro-ph/0401618},
year = {2007}
}
Comments
17 pages, 16 figures, replaced with version accepted by MNRAS. Primordial bispectrum recalculated and figure 11 changed