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the theoretical understanding of Type Ia Supernovae. Daniel Kasen. SN cosmology. “super-nova”. Supernova Discovery History Asiago Catalog (all supernova types). Proposed. Supernova Factory Lick observatory SN search CfA SN group Carnegie SN project ESSENCE Supernova Legacy Survey.
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the theoretical understanding of Type Ia Supernovae Daniel Kasen
SN cosmology “super-nova” Supernova Discovery HistoryAsiago Catalog (all supernova types)
Proposed Supernova Factory Lick observatory SN search CfA SN group Carnegie SN project ESSENCE Supernova Legacy Survey PanStarrs Dark Energy Survey JDEM Large Synoptic Survey Telescope (LSST) Supernova Discovery FutureRough predictions and promises… Dark Energy Measurements Systematic error, not statistical error, is the issue (e.g., luminosity evolution) Aim for Type Ia SNe as reliable standard candles to a few %
SN Ia ProgenitorsAccreting white dwarf near the Chandrasekhar limit Accretion rate: 10-7 Msun / year
t = 0.0 sec t = 0.5 sec t = 1.0 sec t = 1.5 sec 3D Deflagration ModelSubsonic turbulent flame burning Roepke et al. (2005)
C/O Si/S/Ca 56Ni Fe C/O boom
Type Ia Supernova Light Curvespowered by the beta decay: 56Ni 56Co 56Fe
Type Ia Supernova Spectrum 20 days after explosion
Spectroscopic Homogeneity and Diversitymonitoring silicon expansion velocities from Leonard et al, ApJ 2006
Type Ia Width-Luminosity Relationbrighter supernovae have broader light curves
FeII bound-bound Supernova Ejecta Opacityblending of millions of line transitions FeIII bound-bound
DOE: Scientific Discovery through Advanced Computing (SciDAC) The “Computational Astrophysics Consortium” (CAC) Stan Woosley (PI) UC Santa Cruz, UC Berkeley, Stanford, Arizona, Stony Brook, JHU, LANL, LLNL, LBNL Models Presupernova Evolution (~100-109 years) accreting, convective white dwarf Type Ia supernova theoretical simulation challenge ignition Explosion (~1-100 secs) turbulent nuclear combustion / hydrodynamics free expansion Light Curves / Spectra (~100 days) radioactive decay / radiative transfer Observations
3-dimensional Time-Dependent Monte Carlo Radiative Transfer SEDONA Code Expanding atmosphere Realistic opacities Three-dimensional Time-dependent Multi-wavelength Includes spectropolarization Includes radioactive decay and gamma-ray transfer Iterative solution for thermal equilibrium Kasen et al 2006 ApJ
Large Scale Computing Incite award, Oak Ridge Lab: 4 million hours/year Atlas “grand challenge” LLNL: 4 million hours/year NERSC award, LBL: 3 million hours/year Jacquard, NERSC
C/O Si/S/Ca 56Ni Fe Grid of Type Ia Supernova Models w/ Stan Woosley Sergei Blinikov Elena Sorokina 130 one-dimensional Chandrasekhar mass models with varied composition Parameters MFe MNi MSi “mixing” MFe +MNi +MSi + Mco = MCH
Broadband Synthetic Light CurvesModel Compared to observations of SN 2001el Parameters MFe = 0.1 Msun MNi = 0.6 Msun MSi = 0.4 Msun Kasen, ApJ 2006 Kasen (2006) ApJ
Day 15 after explosion Time Evolution of SpectrumRecession of photosphere reveals deeper layers Day 35 after explosion C/O Si/S/Ca Model SN1994D 56Ni Fe
Width-Luminosity RelationshipKasen and Woosley, ApJ, 2007 Vary 56Ni production MNi = 0.35 to 0.70 Msun
The Width-Luminosity RelationshipKasen and Woosley, ApJ, 2007 Brighter models are hotter and more ionized and have different opacity behavior Vary 56Ni production
The Width-Luminosity RelationshipKasen and Woosley, ApJ, 2007 Vary silicon production (explosion energy) Vary 56Ni production
2D Deflagration Model Roepke, Kasen, Woosley MNi = 0.2 Msun EK = 0.3 x 1051 ergs
DeflagrationToDetonationKhokhlov (1991)Hoeflich (1994)Gamezo et al (2005) Gamezo et al. But how to detonate?
2D Delayed Detonation Roepke, Kasen, Woosley Earlier Detonation (higher densities) gives more 56Ni production MNi = 0.5 Msun EK = 1.2 x 1051 ergs
Off-Center Ignition University of Chicago FLASH Center
Detonation From Failed DeflagrationPlewa, ApJ (2007) Is the transition robust in 3-dimensional calculations?
Asymmetry and SN Ia DiversityB-band Light Curve and the Phillips Relation
The Theoretical Understanding of Type Ia Supernovae Pressing Questions How and where does ignition happen? How might the deflagration transition into a detonation? Can we reproduce the observed spectra and light curves from first principles? How do the light curves depend upon progenitor environment?