Re: Serena's template

From: Chris Lidman (clidman@eso.org)
Date: Sun Mar 28 2004 - 18:20:41 PST

  • Next message: Lifan Wang: "Re: Serena's template"

    Dear Lifan,
       I concur with Rob's e-mail. I had a quick look at the R-I colours
    of the SNe in Jha's thesis. I find many examples that are significantly
    bluer than R-I=-0.24 at maximum B-band light. I'll add the caveat that
    I have not k-corrected these SNe, nor have I corrected for extinction,
    so a more
    detailed check of the Jha data is warranted.

       The Jha data set is independent from the data used by Serena and
    Rob, so it provides us with an opportunity to check and
    refine our templates for future work.

    Regards,

    Chris.

    "Robert A. Knop Jr." wrote:

    > On Sun, Mar 28, 2004 at 04:37:54PM -0800, Lifan Wang wrote:
    >> I do not believe R-I can be anywhere close to -0.4 at optical
    >> maximum of a normal SN Ia. My light curve fits show most of the SNe
    >> with z
    >> < 0.005 show -0.24 at B-max. R-I = -0.4 is beyond reasonable physics.
    >
    > Here's your problem.
    >
    > Whatever you believe your understanding of the physics of supernovae
    > is, the simple fact is that many supernovae are observed to have
    > R-I~-0.4 around maximum. Both Serena and I have seen it. Observations
    > are going to trump preconceptions about what the physics ought to be
    > every time.
    >
    > Here are some of the colors I have (note that some of these suffer a
    > little host galaxy extinction, too!)
    >
    > SN stretch epoch color (R-I)
    > --------------------------------------
    > 1994M 0.887 3.3 -0.43 +- 0.04
    > 1994S 1.035 0.9 -0.49 +- 0.06
    > 1994ae 1.010 -0.4 -0.42 +- 0.04
    > 1994ae 1.010 0.6 -0.45 +- 0.04
    > 1995D 1.118 -1.0 -0.30 +- 0.05
    > 1995D 1.118 -0.2 -0.27 +- 0.07
    > 1995D 1.118 1.7 -0.38 +- 0.06
    > 1995al 1.084 0.5 -0.35 +- 0.06
    > 1995al 1.084 1.4 -0.35 +- 0.08
    > 1995ac 1.090 -2.5 -0.21 +- 0.04
    > 1995ac 1.090 0.0 -0.29 +- 0.05
    > 1995bd 1.040 0.3 -0.35 +- 0.04
    > 1995bd 1.040 1.2 -0.42 +- 0.05
    > 1996X 0.901 0.2 -0.32 +- 0.03
    > 1996X 0.901 1.3 -0.37 +- 0.04
    > 1996bl 1.033 -1.6 -0.23 +- 0.04
    > 1996bo 0.841 -1.6 -0.34 +- 0.01
    > 1996bo 0.841 0.7 -0.31 +- 0.01
    > 1992al 0.958 1.7 -0.40 +- 0.04
    > 1992bc 1.081 1.4 -0.50 +- 0.03
    > 1992bo 0.737 0.0 -0.27 +- 0.04
    > 1992bo 0.737 1.3 -0.32 +- 0.05
    >
    > -Rob
    >
    > --
    > --Prof. Robert Knop
    > Department of Physics & Astronomy, Vanderbilt University
    > robert.a.knop@vanderbilt.edu

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