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pythonastronomyhealpy

Fast way to convolve a non-centered gaussian with a healpy map?

I have a healpix map (nside=256) and I am trying to convolve it with a gaussian, which is not centered, this is, simulating an offset in the 'telescope pointing'. Is there an easy way of doing this?

I know `healpy.smoothing' works for usual gaussians, but have not been able to find anything for this case.

Solution

  • What if you convolve the map with hp.smoothing and now you have a uniformly smoothed map.

    Then when you observe it to turn it into a timestream, you add an offset to your pointing, so instead of picking the "right" pixel, you pick instead one of the nearby pixels.

    So let's say you have theta and phi and pointing errors dtheta and dphi, you do:

    pix = hp.ang2pix(256, theta+dtheta, phi+dphi)