From: Greg Aldering (aldering@panisse.lbl.gov)
Date: Thu Jun 10 2004 - 22:10:04 PDT
Hi Vitaliy,
I looked at the various fits you made for 99qQ with an eye towards
understanding why the peak magnitudes change so much (well outside the
quoted uncertainties) when the discovery point is added. I figured that
the the poorer chi^2 when this point is added were likely caused by this
point being fit poorly.
However, this discovery point fits just fine! Instead it appears that the
new lightcurve parameters from R->B then make the I->V fits worse. In the
case of Peter's template, the poor fit is due to a weird drop in the
template lightcurve at late times, which completely misses the HST point.
Overall, I was struck by the highly structured (not smooth) shape of the
templates we are now fitting. The B-band template has a straight - rather
than rounded - pre-max face, and the templates are very pointy near
maximum (especially in V-band). Serena's V-band template as plotted on
these fits appears to have some numerical artifacts near max (the 2nd
derivative is discontinuous), and as mentioned above there is a spurious
"shelf" at late times in the Peter template.
A question for the group then is do all the lightcurve fits we are now
performing have these highly-structured template lightcurves? If so, is
this structure thought to be real or due to artifacts in the construction
of the templates? Perhaps this has more to do with how SNminuit is
interpolating the lightcurves?
Signed,
Curious Greg
On Thu, 10 Jun 2004, Vitaliy Fadeyev wrote:
>
>
> Dear Serena,
>
> please find the results below. For comparison, I show the snminuit runs
> for Robs' template, new "precise" Peter template (supplied by Rollin),
> and the one supplied by you.
>
> Cases are:
>
> 1R - HST only, Rob's template
> 1P - HST only, Peter's template
> 1S - HST only, Serena's template
> 2R - HST and discovery point, Rob's template
> 2P - HST and discovery point, Peter's template
> 2S - HST and discovery point, Serena's template
> 3R - HST and discovery point, tmax fixed to Tonry's, Rob's template
> 3P - HST and discovery point, tmax fixed to Tonry's, Peter's template
> 3S - HST and discovery point, tmax fixed to Tonry's, Serena's template
>
> SNMINUIT output table:
> case m_B dm_R m_B_corr dm_B_corr s ds chisq dof m_R kcorr_R kcorr_I tmax dtmax R-I d(R-I)
>
> 1R 22.82 0.06 23.02 0.16 1.117 0.054 5.29 8 22.06 -0.764 -0.310 2451186.54 1.444 -0.054 0.074
> 1P 22.36 0.05 22.45 0.13 1.035 0.044 5.74 8 21.66 -0.702 -0.189 2451178.16 1.676 0.005 0.049
> 1S 22.63 0.04 22.77 0.13 1.074 0.046 4.13 8 22.04 -0.585 -0.297 2451186.90 1.497 0.121 0.061
>
> 2R 23.14 0.02 23.34 0.07 1.119 0.032 9.95 9 22.24 -0.902 -0.419 2451191.83 0.853 -0.188 0.035
> 2P 23.36 0.02 23.57 0.08 1.119 0.033 13.86 9 22.22 -1.140 -0.538 2451192.44 0.729 -0.414 0.031
> 2S 23.08 0.02 23.34 0.09 1.162 0.038 14.61 9 22.26 -0.826 -0.484 2451191.26 0.878 -0.115 0.042
>
> 3R 23.22 0.02 23.31 0.06 1.040 0.022 26.92 10 22.23 -0.986 -0.484 2451194.65 0.000 -0.269 0.031
> 3P 23.41 0.02 23.52 0.05 1.056 0.017 24.92 10 22.22 -1.186 -0.575 2451194.65 0.000 -0.459 0.029
> 3S 23.20 0.01 23.33 0.05 1.065 0.018 34.39 10 22.25 -0.943 -0.574 2451194.65 0.000 -0.228 0.029
>
>
> The snminuit plots are here:
> (case 1R) http://www-physics.lbl.gov/~fadeyev/snminuit_sn1999q_HSTonly.ps
> (case 1P) http://www-physics.lbl.gov/~fadeyev/snminuit_sn1999q_HSTonly_uberPeter.ps
> (case 1S) http://www-physics.lbl.gov/~fadeyev/snminuit_sn1999q_HSTonly_uberSerena.ps
> (case 2R) http://www-physics.lbl.gov/~fadeyev/snminuit_sn1999q_HSTdisc.ps
> (case 2P) http://www-physics.lbl.gov/~fadeyev/snminuit_sn1999q_HSTdisc_uberPeter.ps
> (case 2S) http://www-physics.lbl.gov/~fadeyev/snminuit_sn1999q_HSTdisc_uberSerena.ps
> (case 3R) http://www-physics.lbl.gov/~fadeyev/snminuit_sn1999q_HSTdisc_fixtmax.ps
> (case 3P) http://www-physics.lbl.gov/~fadeyev/snminuit_sn1999q_HSTdisc_fixtmax_uberPeter.ps
> (case 3S) http://www-physics.lbl.gov/~fadeyev/snminuit_sn1999q_HSTdisc_fixtmax_uberSerena.ps
>
> I should note that cases 1P and 1S took a lot of time to converge.
> Cases 3R,3P,3S have fairly large Chi^2 due to the late-time behaviour
> being somewhat incompatible with the assumed tmax from Tonry.
>
> Cheers,
> vitaliy
>
>
> Serena Nobili wrote:
>
> >Dear Vitaliy (cc SCPexec),
> >
> >as you probably know, a new set of spectral template has been produced by
> >Peter Nugent so to solve some problems of the I-band paper. I have been
> >working to color correct them (see attachment) repeating the analysis done
> >in Nobili et al. 2003. I would like to ask you if you could run SNminuit
> >to fit the B and V- band lightcurve of 1999Q using the new templates. This
> >should close the analysis and maybe give us a better understanding of this
> >SN. I hope this will not be too much work for you. Please, let me know if
> >you think you don't have the time to work on it right now. Thank you very
> >much for your help.
> >Cheers,
> >
> > Serena
> >
> >
> >----------------------------------------------------------------------
> >www.physto.se/~serena
> >Tel +33 1 44 27 75 82
> >
> >Give free food at:
> >http://www.porloschicos.com/
> >http://www.thehungersite.com/
> >
> >
> >
> >
>
>
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