2009-06-17

double redshifts

Vivi Tsalmantza and I attempted to re-start our project looking for double-redshifts in the SDSS spectroscopy. We discussed the issues of wavelength coverage—which, with empirical galaxy templates, is a function of the two redshifts—and interpolation, which ought to be done by cubic spline (with SDSS spectra, at least). I started writing up the issue of hypothesis testing in this situation of variable wavelength coverage.

1 comment:

  1. Cameron McBride19 June, 2009 13:43

    Wouldn't it be better to use an AKIMA spline rather than cubic? The galaxy templates might be well behaved, but an AKIMA spline could prevent oscillations between them which might result in a spurious fit.

    http://www.alglib.net/interpolation/spline3.php

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