Project for ASTR7741

Fall Semester, 2007

Observations seem to support the idea that Type Ia supernovae are very good "standard candles." So good, in fact, that they have been used in the context of cosmological distance determinations to show that the universe is accelerating.

Actually, Type Ia SN do not all share precisely the same light curves and, in particular, the peak brightness varies from system to system. However, there appears to be a tight correlation between the intrinsic peak brightness and the timescale for decay of Type Ia supernova lightcurves. In fact, an empirical algorithm exists that can be used to "scale" every Type Ia supernova lightcurve into a single "standard" lightcurve. It is in this sense that Type Ia SN have proven to be useful standard candles.

Background

• Webbink's PowerPoint Talk (Oct. 25, 2007)
• Webbink's Bibliography (Oct. 25, 2007)

• The curves shown in Webbink's talk were taken directly from the figure titled "Low Redshift Type Ia Template Lightcurves" posted by Kevin Krisciunas. Krisciunas, in turn, references the following group of key papers on this subject:
  • Phillips, M. M. 1993, "The Absolute Magnitudes of Type Ia Supernovae," Astrophysical Journal, 413, L105
  • Phillips, M. M., Lira, P., Suntzeff, N. B., Schommer, R. A., Hamuy, M. & Maza, J. 1999, "The Reddening-Free Decline Rate Versus Luminosity Relationship for Type Ia Supernovae," Astronomical Journal, 118, 1766.
  • Riess, A. G., Press, W. H., & Kirschner, R. P. 1996, "A Precise Distance Indicator: Type Ia Supernova Multicolor Light-curve Shapes," ApJ, 473, 88.
  • Perlmutter et al. (1997)
  • Goldhaber et al. [includes Brad Schaefer as one of the authors] 2001, "Timescale Stretch Parameterization of Type Ia Supernova B-Band Light Curves," ApJ, 558, 359.

• Woosley, S. E., Kasen, D., Blinnikov, S., & Sorokina, E. 2007, "Type Ia Supernova Light Curves," ApJ, 662, 487.
• Kasen, D., & Woosley, S. E. 2007, "On the Origin of the Type Ia Supernova Width-Luminosity Relation," ApJ, 656, 661.
• Baron, E., Bongard, S., Branch, D., & Hauschildt, P. H. 2006, "Spectral Modeling of SNe Ia Near Maximum Light: Probing ...," ApJ, 645, 480.
• Dominguez, I., et al. 2006, "Rotating Type Ia SN Progenitors: Explosion and Light Curves," ApJ, 644, 21.
• Timmes, F. X., Brown, E. F., & Truran, J. W. 2003, "On Variations in the Peak Luminosity of Type Ia Supernovae," ApJ Letters, 590, L83.
• OVERVIEW: Hoeflich, P., Gerardy, C., Linder, E., & Marion, H. 2003, "Models for Type Ia Supernovae and Cosmology," astro-ph/0301334