Bibcode
Savage, Richard; Battye, Richard A.; Carreira, Pedro; Cleary, Kieran; Davies, Rod D.; Davis, Richard J.; Dickinson, Clive; Genova-Santos, Ricardo; Grainge, Keith; Gutiérrez, Carlos M.; Hafez, Yaser A.; Hobson, Michael P.; Jones, Michael E.; Kneissl, Rüdiger; Lancaster, Katy; Lasenby, Anthony; Leahy, J. P.; Maisinger, Klaus; Pooley, Guy G.; Rajguru, Nutan; Rebolo, Rafael; Rocha, Graca; Rubiño-Martin, J. A.; Saunders, Richard D. E.; Scott, Paul; Slosar, Anžce; Molina, Pedro Sosa; Taylor, Angela C.; Titterington, David; Waldram, Elizabeth; Watson, Robert A.
Referencia bibliográfica
Monthly Notices of the Royal Astronomical Society, Volume 349, Issue 3, pp. 973-982.
Fecha de publicación:
4
2004
Número de citas
14
Número de citas referidas
14
Descripción
We have tested Very Small Array (VSA) observations of three regions of
sky for the presence of non-Gaussianity, using high-order cumulants,
Minkowski functionals, a wavelet-based test and a Bayesian joint power
spectrum/non-Gaussianity analysis. We find the data from two regions to
be consistent with Gaussianity. In the third region, we obtain a 96.7
per cent detection of non-Gaussianity using the wavelet test. We perform
simulations to characterize the tests, and conclude that this is
consistent with expected residual point source contamination. There is
therefore no evidence that this detection is of cosmological origin. Our
simulations show that the tests would be sensitive to any residual point
sources above the data source subtraction level of 20 mJy. The tests are
also sensitive to cosmic string networks at an rms fluctuation level of
105 μK (i.e. equivalent to the best-fitting observed value). They are
not sensitive to string-induced fluctuations if an equal rms of Gaussian
cold dark matter fluctuations is added, thereby reducing the rms
fluctuations due to the strings network to 74 μK. We especially
highlight the usefulness of non-Gaussianity testing in eliminating
systematic effects from our data.