2dFGRS Data Release
Power Spectrum

The power spectrum data and appropriate covariance matrix from Percival et al. (2001, MNRAS, 327, 1297) are available as text files from the links below. They are designed to be self-explanatory, but in the event of problems please send an email to Will Percival.

Because of the difficulty of performing a 3D convolution with the appropriate survey window function (given a model power spectrum), a simple C program that demonstrates how this may be achieved for any k-value is also available (note that this comes with no warranty).

Given a sufficiently smooth P(k), it is possible to speed up this process using the window function in matrix form. Such a matrix is also available from a link below for determining the convolved power spectrum at the k-values of the data. This file is organised as follows: the first line gives the k-values at which the convolved P(k) is being calculated (chosen to be the same as the data); each subsequent line gives the k-value at which the unconvolved P(k) should be determined (100 points), and the weights required to calculate the 32 convolved P(k) values. The simple program given below demonstrates how to use this matrix and compares the result with the numerically convolved P(k). If you use the matrix method, it is suggested that you check that the power spectra that you wish to convolve are sufficiently smooth that the two methods give the same answer (to the required accuracy).

If you download these data or programs please send an email to Will Percival so that you can be contacted in case of updates or corrections.

Matthew Colless, colless@aao.gov.au, Fri 7 Jul 2006, 48th access