TY - JOUR
T1 - Cosmological parameter estimation using Very Small Array data out to ℓ =1500
AU - Rebolo, Rafael
AU - Battye, Richard A.
AU - Carreira, Pedro
AU - Cleary, Kieran
AU - Davies, Rod D.
AU - Davis, Richard J.
AU - Dickinson, Clive
AU - Genova-Santos, Ricardo
AU - Grainge, Keith
AU - Gutiérrez, Carlos M.
AU - Hafez, Yaser A.
AU - Hobson, Michael P.
AU - Jones, Michael E.
AU - Kneissl, Rüdiger
AU - Lancaster, Katy
AU - Lasenby, Anthony
AU - Leahy, J. P.
AU - Maisinger, Klaus
AU - Pooley, Guy G.
AU - Rajguru, Nutan
AU - Rubiño-Martin, José Alberto
AU - Saunders, Richard D E
AU - Savage, Richard S.
AU - Scaife, Anna
AU - Scott, Paul F.
AU - Slosar, Anže
AU - Molina, Pedro Sosa
AU - Taylor, Angela C.
AU - Titterington, David
AU - Waldram, Elizabeth
AU - Watson, Robert A.
AU - Wilkinson, Althea
PY - 2004/9/21
Y1 - 2004/9/21
N2 - We estimate cosmological parameters using data obtained by the Very Small Array (VSA) in its extended configuration, in conjunction with a variety of other cosmic microwave background (CMB) data and external priors. Within the flat A cold dark matter (ACDM) model, we find that the inclusion of high-resolution data from the VSA modifies the limits on the cosmological parameters as compared to those suggested by the Wilkinson Microwave Anisotropy Probe (WMAP) alone, while still remaining compatible with their estimates. We find that Ω bh 2 = 0.0234 -0.0014 +0.0012, Ω dmh 2 = 0.111 -0.016 +0.014, h = 0.73 -0.05 +0.09, n S = 0.97 -0.03 +0.06, 10 10A S = 23 -3 +7 and τ = 0.14 -0.07 +0.14 for WMAP and VSA when no external prior is included. On extending the model to include a running spectral index of density fluctuations, we find that the inclusion of VSA data leads to a negative running at a level of more than 95 per cent confidence (n run = -0.069 ± 0.032), something that is not significantly changed by the inclusion of a stringent prior on the Hubble constant. Inclusion of prior information from the 2dF galaxy redshift survey reduces the significance of the result by constraining the value of Ω m. We discuss the veracity of this result in the context of various systematic effects and also a broken spectral index model. We also constrain the fraction of neutrinos and find that f v <0.087 at 95 per cent confidence, which corresponds to m v <0.32 eV when all neutrino masses are equal. Finally, we consider the global best fit within a general cosmological model with 12 parameters and find consistency with other analyses available in the literature. The evidence for n run <0 is only marginal within this model.
AB - We estimate cosmological parameters using data obtained by the Very Small Array (VSA) in its extended configuration, in conjunction with a variety of other cosmic microwave background (CMB) data and external priors. Within the flat A cold dark matter (ACDM) model, we find that the inclusion of high-resolution data from the VSA modifies the limits on the cosmological parameters as compared to those suggested by the Wilkinson Microwave Anisotropy Probe (WMAP) alone, while still remaining compatible with their estimates. We find that Ω bh 2 = 0.0234 -0.0014 +0.0012, Ω dmh 2 = 0.111 -0.016 +0.014, h = 0.73 -0.05 +0.09, n S = 0.97 -0.03 +0.06, 10 10A S = 23 -3 +7 and τ = 0.14 -0.07 +0.14 for WMAP and VSA when no external prior is included. On extending the model to include a running spectral index of density fluctuations, we find that the inclusion of VSA data leads to a negative running at a level of more than 95 per cent confidence (n run = -0.069 ± 0.032), something that is not significantly changed by the inclusion of a stringent prior on the Hubble constant. Inclusion of prior information from the 2dF galaxy redshift survey reduces the significance of the result by constraining the value of Ω m. We discuss the veracity of this result in the context of various systematic effects and also a broken spectral index model. We also constrain the fraction of neutrinos and find that f v <0.087 at 95 per cent confidence, which corresponds to m v <0.32 eV when all neutrino masses are equal. Finally, we consider the global best fit within a general cosmological model with 12 parameters and find consistency with other analyses available in the literature. The evidence for n run <0 is only marginal within this model.
KW - Cosmic microwave background
KW - Cosmology: observations
U2 - 10.1111/j.1365-2966.2004.08102.x
DO - 10.1111/j.1365-2966.2004.08102.x
M3 - Article
SN - 1365-2966
VL - 353
SP - 747
EP - 759
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 3
ER -