Name | Last modified | Size | Description | |
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Parent Directory | - | |||

maxima1_4det_pix8am_..> | 2002-01-30 15:39 | 136M | ||

maxima1_4det_pix8am_..> | 2002-02-07 18:59 | 136M | ||

combined_4det_beam | 2002-01-31 09:54 | 25K | ||

This directory contains the MAXIMA-1 map and pixel-pixel noise correlations. Downloadable data: maxima1_4det_pix8am_rescale.fits - A portable FITS file containing the 4-detector MAXIMA-1 map, pixelized with 8 arcminute resolution. maxima1_4det_pix8am_rescaled.idl - A portable IDL file containing the 4-detector MAXIMA-1 map, pixelized with 8 arcminute resolution. You will need IDL version 5.4 or later to use this file. combined_4det_beam - A text file of B_l, the beam window function, as it depends on the multipole l. This is an effective beam function for the 4-detector combination. To remove the affect of beam size from your analysis, divide the power spectrum by the square of these numbers. Other available data: The 4-detector data are available by request at higher resolution and in different document formats. Contact bahman@cosmology.berkeley.edu for more information. MAXIMA pixelisation-projection scheme ---------------------------- Below follow some notes on the MAXIMA pixelisation to allow people familiarized with FITS jargon to visualize MAXIMA maps quickly. MAXIMA-1 data maps are projected according to the pseudo-cylindrical Sanson-Flamsteed projection, an equal-area projection with projection law (Calabretta & Greisin 2001): x=(alpha-alpha0) cos(delta) y=delta where x and y are the projected native coordinates. 1) To pass from celestial coordinates to pixel coordinates x=(alpha-alpha0) cos(delta) y=delta ix= x/ CDELT1 + CRPIX1 iy= y/ CDELT2 + CRPIX2 where alpha = right ascension delta = declination alpha0 = right ascension of the meridian center of the map = CRVAL1 CRPIX1, CRPIX2 = central reference pixels of the map CDELT1, CDELT2 = angular pixel sizes (increments) ix, iy = pixel coordinates of the map 2) To pass from pixel coordinates to celestial coordinates x= (ix-CRPIX1)* CDELT1 y= (iy-CRPIX2)* CDELT2 delta=y alpha= x /cos(y) + alpha0 Note : since the reference point for the projection has alpha_p=alpha0, delta_p=0, the rotation of reference frame is equivalent to adding up alpha0 to the alpha coordinates (a consequence of setting up CRVAL2=0) For these maps: CDELT1, CDELT1 = 8 arcmin alpha0 = 14.8 hours (don't forget to put everything in the same angular units). CRPIX1, CRPIX2 = you choose, but it should correspond to the center point of your displayed array image. References: "Representations of celestial coordinates in FITS", 2001, =========== M.Calabretta & E.W.Greisen, A&A draft (http://www.atnf.csiro.au/people/mcalabre/index.html [Domingos Barbosa 02/25/02]