Re: HST paper - high-redshift stretch-luminosity relation

From: Alex Kim (agkim@lbl.gov)
Date: Sun Apr 27 2003 - 09:16:06 PDT

  • Next message: Alex Kim: "HST paper - dust extinction evolution"

    Greg,

    Interesting plots. Is there a reason that you didn't include the Riess
    low-z supernovae in the plot?

    To satisfy my own curiosity, could you make an ideogram of the magnitude
    residuals after extinction and stretch correction for the low-z and
    high-z supernovae separately? I would like to see the shape of the
    distributions, and compare the luminosity functions of low and high-z SNe.

    Alex

    Ariel Goobar wrote:

    >On Sat, 26 Apr 2003, Greg Aldering wrote:
    >Hi Greg,
    >can you please provide the chisquare for the high-z data w.r.t
    >1) the solid line 2) the no correlation case?
    >Thanks,
    > Ariel
    >
    >
    >>I used the lightcurve fit parameter tables in the paper, along with
    >>cosmology fit residuals supplied by Rob and the values of alpha given in
    >>the paper, to undo the stretch correction that Rob applied when performing
    >>the cosmology fits. I have attached postscript plots showing the
    >>stretch-lumnosity relation of our HST SNe, superimposed on that for the
    >>Hamuy SNe, for your consideration. The first plot uses the SN data without
    >>extinction correction, while the second plot shows the results after
    >>extinction correction. The solid symbols are our HST SNe, while the open
    >>symbols are the low-redshift SNe.
    >>
    >>Note that (to my knowledge) we have never published a stretch-luminosity
    >>relation! Those of you who have never made such a plot for yourself might
    >>be surprised that the extinction-corrected relation for the low-redshift
    >>SNe is not prettier. However, the deviations you see here are common to
    >>the various stretch analyses I have seen. You also see that there is no
    >>convincing relation at all for the high-redshift SNe by themselves. Note
    >>however that the high-redshift SNe clearly populate the same parts of the
    >>diagram, including tracking some of the systematic deviations, as the
    >>low-redshift SNe. (Of course the deviations for the high-redshift SNe are
    >>not as significant as those for the low-redshift SNe because the error
    >>bars are larger.) If we put one or both of these plots in the paper, I
    >>think it would at least show that the low- and high-redshift datasets are
    >>similar in their stretch-luminosity behavior.
    >>
    >>I would be interested in people's reaction to including such a plot in the
    >>paper.
    >>
    >>Cheers,
    >>
    >>Greg
    >>
    >>
    >>
    >
    >
    >

    This archive was generated by hypermail 2.1.4 : Sun Apr 27 2003 - 09:16:44 PDT