1. Ay 123: Supernovae contd..

2. Nucleosynthesis - revisited
Fe peak Z Z N
Hydrostatic equilibrium slowly builds up He4 through Fe56
Equilibrium `e-process’ postulated to explain `Fe peak’ abundances: more stable = more abundant A

3. Decay of Nuclei and SN II light curves
Ni56 t=6.1d
Co56 t=77d
SN1987A: McCray ARAA 31, 175 (1993)

4. The Ring Around SN1987A Original FOC image (1990) Post-repair image
1.66”
IUE observes a brightening in UV emission lines 413d after SN explosion - pre-SN ejecta is being illuminated by the explosion. Resolving the diameter of the ring gives its size and an absolute distance to the LMC
Panagia et al Ap J 380, L29 (1991)

5. Cosmological Distances from SN II P
Flux, temperature & expansion velocity during `plateau phase’

6. Hubble Diagram for SNe IIP
scatter = 0.26 mag
(for Ia scatter~0.20)
Could detect acceleration with present technology (~15 SNIIP)
More effectively probe to high z with JWST/TMT (Nugent et al 2006)

7. SN Ia Light Curve Shape - Luminosity Correlation
Reduces scatter on `Hubble diagram’
No correction
Correction
Phillips 1993 Ap J 413, L105; Riess et al 1995 Ap J 438, 17

8. Host Galaxy Dependence of SNe Ia Properties
Ia rate
SFR/mass
Width of light curve
SN Ia rate correlates with specific SFR of host galaxy
Light curve `stretch’ likewise correlates
SN properties depend on mix of stellar population
Sullivan et al Ap J 648, 868 (2006)

9. Routes to a SNeIa in single degenerate C-O WD systems (Nomoto et al astro-ph/9907386)
AGB with C+O core
RG+He core
WD + MS in common envelope
WD + red giant
Wind reduces rate
Short time delay
Significant time delay

10. Cosmic Acceleration From SNe Ia
Perlmutter et al 1999
Light curve corrected peak luminosities give luminosity distance
Redshifts give cosmic expansion velocities
SNe Ia are too faint for a given redshift c.f. decelerating models!

11. Implications of Cosmic Acceleration
Why not ? two puzzles:
expect = 8GmP4
(10120 larger)
Why acceleration now?
M  R-3 (matter)
vac = const (vacuum)
Perlmutter et al 1999
Alternative: new physics - “dark energy”: quintessence: equation of state p = w ;  R-3(1+w) dynamical scalar field w = w(t)

12. Deep HST Survey
Riess et al Ap J 659, 98 (2007)

13. First Year Results from CFHT SNLS
Astier et al A&A 447, 31 (2006)
71 homogenously studied SNe Ia
w = ± 0.090
i.e. equivalent to Cosmological Constant