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Supernovae and the Accelerating/Decelerating Universe. Adam G. Riess. Space Telescope Science Institute. How (we think) Nature makes a SN Ia. Homogeneity: 1.4 Mo, ergs Negligible hydrogen, lots of IME Mature progenitors Models (delayed-detonation) good fit to observations.
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Supernovae and the Accelerating/Decelerating Universe AdamG. Riess Space Telescope Science Institute
How (we think) Nature makes a SN Ia • Homogeneity: 1.4 Mo, ergs • Negligible hydrogen, lots of IME • Mature progenitors • Models (delayed-detonation) good fit to observations
“Standard” Candles dust dim & red=closer! Bright=near dim=far
Expansion History of the Universe Mass is destiny (redshift) (Distance)
The Accelerating Universe By 1998 two teams measured ~100 SNe Ia at 0.01 <z<1.0 Surprise! The Universe is accelerating, propelled by dark energy. High-z SCP
Deceleration Searching for the Epoch of …a required feature of a mixed dark matter/dark energy Universe dust or evolution? z accelerating 0.0 0.4 0.8 1.2 1.7 0.4 1.0 2.3 4.3 8.0 decelerating
Deceleration Searching for the Epoch of z 0.0 0.4 0.8 1.2 1.7 0.4 1.0 2.3 4.3 8.0 Our current goal: 6-8 SNe Ia at 1.2<z<1.8
“Difficulty” Or why its so hard to find type Ia supernovae at z>1.2 Total=6 Finding SNe Ia at 1.2<z<1.8 is 10 to 40 times harder than at z=0.5 (a.k.a., 1998)
The GOODs ACS Treasury Program and The Hubble Higher-z Supernova Search Team “A Higher-z Supernova Search Piggybacking on the ACS Survey” 134 orbits ToO for 6-8 SNe Ia at 1.2<z<1.8 Riess (STScI) Strolger (STScI) Tonry (UH) Filippenko (UCB) Kirshner, (CfA) Challis, (CfA) Casertano, (STScI) Dickinson (STScI) Giavalisco (STScI) Ferguson (STScI) 399 orbits of deep imaging for extragalactic studies
Searching for SNe Ia with ACS 5 z-band epochs, spaced by 45 days, simultaneous v,i band, 120 tiles CDFS=08/02-02/03 HDFN=11/02-05/03
What we are finding… ~5-6 SNe per search epoch (~0.3 SNe/ACS pointing) ~1/2 type Ia, ~1/2 core-collapse, 0.3<z<1.8, <z>=1
SN Color Differences SN Ia UV deficit z i v Most Common SN types: type Ia and type II
Our first higher-z SN Ia, Aphrodite Aphrodite (1<z<1.5) ACS F850lp ACS grism spectrum NICMOS F110W viz
The Rise and Fall of Aphrodite Oct 20 Oct 1 Nov 17 Aug 1 Oct 5 Sept 22 Oct 30 Oct 31 Nov 25 Oct 10
Our Second Higher-z SN Ia, Thoth Epoch 2 Epoch 3 Epoch 3-2 red, elliptical host Keck VLT z=1.3
Our Third Higher-z SN Ia, Nanna Epoch 1 Epoch 2 difference OII, Keck
And Some Even More Distant… Athena: phot-z: 1.8<z<2.2 Colors, mag SN Ia at z~1.8 Osiris: Colors, mag SN Ia at 1.5<z<1.8 ACS f850lp viz We are off to a great start…results coming soon to a journal near you…
Dilution of Light or Gravity Depends onthe Number of Dimensions Either “Sees” Essential component of String Theory: photons move in 3 dimensions, Gravitons leaks into 5,10 or 11 D long-range decay of gravity (Dvali et al 2001)
The Future Is Bright for SNe Ia! • New tests of the new cosmology (searching for past deceleration) • Deeper understanding of SNe Ia (progenitors) • Probing the nature of Dark Energy
3 SNe Followed in 1 ACS Field ! SN 2002hq SN Ia 2002hp SN Ia 2002fw
SN Ia Host Morphology z<0.7 high fraction of hosts with well-defined structure z>1.3 high fraction of irregulars and ERO hosts