Supernovae of type Ia: the final fate of low mass stars in close bynary systems Oscar Straniero INAF

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Supernovae of type Ia the final fate of low mass
starsin close bynary systemsOscar Straniero
INAF Oss. Astr. di Collurania (TE)
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CMB Temperature fluctuations (COBE BOOMERANG WMAP)
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• High-z Team
• (Brian Schmidt co)

• Supernova
• Cosmology Project

(Saul Perlmutter co.)
0.25 mag fainter than for an EMPTY Universe
Fainter Further
The Universe is Accelerating
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Standard Model
CMB SNe H0
LCDM model
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SNe CMB
SNe Perlmutter et al. 1998, Riess et al.
1998 14.5"1 Gyr (Ho63) SNeWMAPHST 13.2"0.4
Gyr (Ho71) Spergel et al. 2003 13.7"0.2
Gyr
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SNe Classification
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Standard Candles

• Bright
• Homogeneous
• No evolutionary effects

Supernovae Ia
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Thermonuclear Explosion of a CO
WD MMChandrasekhar
Light Curve
L
56Ni ? 56Co ?56 Fe
1.4 M?
time
L ? MNi
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Observed Relations
Riess et al. , 1997
Brighter Slower Decline Dimmer Faster
Decline
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Maximum Brightness - Decline Relation
Phillips et al. 1996, 1999
lt?gt 0.17 mag
Calibrated locally
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Do Supernovae change with z ??
Hints...

• SN Ia rate is smaller
• in Ellipticals
• Cappellaro et al. 1997
• SN Ia LCs Slower (brighter)
• in Bluer Galaxies
• Hamuy et al. , 1995, 1996
• Branch et al. 1996

Back in timegtgtProgenitors Younger more
metal-poor
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The conceptually simplest model for a
thermonuclear supernova is just an analog of a
runaway chemical reaction that become explosive
a conventional bomb.
bombs often fail. Similarly, most models for
astrophysical bombs (Sne Ia) often fail.
Further, astrophysical bombs must occur
naturally and at the correct rate there must be
a convincing astronomical context.
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The virial theorem
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Massive stars and core collapse
Limongi, Straniero Chieffi, 2001

• e-p à nne (10 MeV)
• 56Feg à 13a4n (124 MeV)

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Evolutionary track of low mass stars
M1 Mu t10 Gyr Remnant CO WD 0.6 Mu
Prada Moroni Straniero 2002
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Stellar evolution
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Astrophysical Explosive Devices
Thermonuclear SNe
Gravitational collapse
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Nucleosynthesisin Thermonuclear SNe
He-detonation
C-deflagration
C-delayed detonation
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SNe Ia Light Curves mass and metallicity effects
Domínguez, Hoflich, Straniero 2001
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H accreting WDs
Most of the accreted material is lost during the
H-pulse too long time
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Merging scenarioDouble degenerate systems COCO
a) GWR loss
b) secondary tidal disruption
c) accretion 10-5 Myr-1
Too fast accretion
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Double Degenerate CO WDs
(M8H10-6 M yr-1)
(M10-8 M yr-1)
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Single Degenerate.Massive WDs the lifting
effect of rotation
H
He
CO
Dominguez, Straniero, Isern Tornambe 1996
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Double DegenerateAngular momentum deposition
GWR
c) accretion 10-5 Myr-1 (expansion)
d) critical accretion (contraction)
e) tri-axial configuration and energy loss via
GWR
f) balance between ang. mom. deposition and
energy loss (steady accretion)
g) Viscous dissipation and explosion
Piersanti, Gagliardi, Iben Tornambe 2003
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Our main results for SNe Ia Up to
?MMAX 0.2 mag C/O WDs due to
different MMS correlated with
vph trise No dependence of
MMAX with initial Z

• Open Problems
• Progenitors ?? ? Accretion, Rotation.
• Propagation of the burning front (1D/3D) ??
  ? Transition density
• How stellar populations evolve with z ??

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The future