Ay 123 Lecture 11 - Supernovae & Neutron Stars Timescales for HS Burning faster and faster..

Structure of Massive Star at End of HS Burning

Neutrinos Arrive from SN1987A Hirata et al Phys. Rev. Lettt 58, 1490 (1987)

Neutrino Trapping

Supernova Discoveries

Supernovae Light Curves II Plateau II Linear Ia Doggett & Branch AJ 90, 2303 (1985)

Supernovae Spectra Thermonuclear: Type Ia: Si, no H Core Collapse: Type II: H emission Type Ib: He, weak H Type Ic: no H, no He Review: Filippenko, ARAA 35, 309 (1997)

Origin of `P Cygni’ Profile P Cygni: luminous blue variable with blue-shifted (absorbing) outflow against core emission

Delayed Explosions

Decay of Nuclei and SN II light curves SN1987A: McCray ARAA 31, 175 (1993) Ni 56 t=6.1d Co 56 t=77d

The Ring Around SN1987A 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 Original FOC image (1990) Post-repair image Panagia et al Ap J 380, L29 (1991) 1.66”

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

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)

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

Host Galaxy Dependence of SNe Ia Properties Ia rate SFR/mass 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) Width of light curve

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

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!

Implications of Cosmic Acceleration Perlmutter et al 1999 Why not  ? two puzzles: expect  = 8  Gm P 4 ( larger) Why acceleration now?  M  R -3 (matter)  vac = const (vacuum) Alternative: new physics - “dark energy”: quintessence: equation of state p = w  ;  R -3(1+w) dynamical scalar field w = w(t)

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

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