Ay123 Lecture I - Physical Properties

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 t6.1d Co56 t77d
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 scatter0.20)
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 CO core
RGHe 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!

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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(1w) dynamical scalar field w w(t)
12
Deep HST Survey
Riess et al Ap J 659, 98 (2007)
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First Year Results from CFHT SNLS
Astier et al AA 447, 31 (2006)
71 homogenously studied SNe Ia w -1.023
0.090 i.e. equivalent to Cosmological Constant