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EVOLUTIONARY PATH TOWARD THE CORE COLLAPSE SUPERNOVA EXPLOSION and Alessandro Chieffi NAF – Istituto di Astrofisica Spaziale e Fisica Cosmica, Ital [email protected] Marco Limongi INAF – Osservatorio Astronomico di Roma, ITALY nstitute for the Physics and Mathematics of the Universe, JAP [email protected]

EVOLUTIONARY PATH TOWARD THE CORE COLLAPSE SUPERNOVA EXPLOSION

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EVOLUTIONARY PATH TOWARD THE CORE COLLAPSE SUPERNOVA EXPLOSION. Marco Limongi INAF – Osservatorio Astronomico di Roma, ITALY Institute for the Physics and Mathematics of the Universe , JAPAN marco.limongi@ oa-roma.inaf.it. and Alessandro Chieffi - PowerPoint PPT Presentation

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Page 1: EVOLUTIONARY PATH TOWARD THE CORE COLLAPSE SUPERNOVA EXPLOSION

EVOLUTIONARY PATH TOWARD THE CORE COLLAPSE SUPERNOVA

EXPLOSION

and

Alessandro ChieffiINAF – Istituto di Astrofisica Spaziale e Fisica Cosmica, Italy

[email protected]

Marco LimongiINAF – Osservatorio Astronomico di Roma, ITALY

Institute for the Physics and Mathematics of the Universe, [email protected]

Page 2: EVOLUTIONARY PATH TOWARD THE CORE COLLAPSE SUPERNOVA EXPLOSION

OVERVIEW OF MASSIVE STARS PRESUPERNOVA EVOLUTIONGrid of models: 13, 15, 20, 25, 30, 40, 60, 80 and 120 M

Initial Solar Composition (Asplund et al. 2009)All models computed with the FRANEC (Frascati RAphson Newton

Evolutionary Code) 6.0Major improvements compared to the release 4.0 (Limongi & Chieffi 2003) and 5.0 (Limongi & Chieffi 2006)

- FULL COUPLING of: Physical Structure - Nuclear Burning - Chemical Mixing (convection, semiconvection, rotation)

- INCLUSION OF ROTATION:- Conservative rotation law- Transport of Angular Momentum (Advection/Diffusion)- Coupling of Rotation and Mass Loss

- TWO NUCLEAR NETWORKS:- 163 isotopes (448 reactions) H/He Burning- 282 isotopes (2928 reactions) Advanced Burning

- MASS LOSS:- OB: Vink et al. 2000,2001- RSG: de Jager 1988+Van Loon 2005 (Dust driven

wind)- WR: Nugis & Lamers 2000/Langer 1989

Page 3: EVOLUTIONARY PATH TOWARD THE CORE COLLAPSE SUPERNOVA EXPLOSION

MASSIVE STARS: CORE H BURNING

g

g

g

g

g

g

g

g

CNO Cycle

Convective Core

Core H burning models

Page 4: EVOLUTIONARY PATH TOWARD THE CORE COLLAPSE SUPERNOVA EXPLOSION

WNL

Page 5: EVOLUTIONARY PATH TOWARD THE CORE COLLAPSE SUPERNOVA EXPLOSION

WNL

Page 6: EVOLUTIONARY PATH TOWARD THE CORE COLLAPSE SUPERNOVA EXPLOSION

MASSIVE STARS: CORE He BURNING

gg

g

g

g

g

g

g

He Convective Core

3a+ 12C(a,g)16O

H burning shellH exhausted

core (He Core)

The Mass Loss rate during the RSG phase is crucial in determining if and

when (at which stage of core He burning) such a transition occurs and if and when the star enters the Wolf-

Rayet stage or becomes a YSG

The location of a core He burning star in the HR diagram depends on the mass of its H

envelope.

Core H burning models

Core He burning models

Core He burning models

WR

Page 7: EVOLUTIONARY PATH TOWARD THE CORE COLLAPSE SUPERNOVA EXPLOSION

WNLWNE WNCWC

WNL

WNEWNC

WC

Page 8: EVOLUTIONARY PATH TOWARD THE CORE COLLAPSE SUPERNOVA EXPLOSION

WNLWNE WNCWC

WNL

WNEWNC

WC

Page 9: EVOLUTIONARY PATH TOWARD THE CORE COLLAPSE SUPERNOVA EXPLOSION

EVOLUTION DURING H AND He BURNING: SUMMARY

Initial Mass

Final Mass

MH MHe Progenitor

SN

13 12.0 5.46 4.49 RSG II-P15 13.4 5.75 4.90 RSG II-P20 8.1 0.25 3.81 RSG IIb25 10.4 0.14 4.42 YSG IIb30 12.6 0.03 4.35 YSG IIb/Ib40 16.0 0.00 4.22 WNE Ib/c60 16.8 0.00 0.93 WC Ib/c80 22.6 0.00 1.07 WC Ib/c

120 30.8 0.00 1.02 WC Ib/c

Compatible with recent observational estimates (Smartt et al. 2009):

Compatible with the observed rates (Cappellaro & Turatto 99)

Live a substantial fraction of time as RSG and explode as as IIb/Ib solve the RSG problem (Smartt et al. 2009)

Page 10: EVOLUTIONARY PATH TOWARD THE CORE COLLAPSE SUPERNOVA EXPLOSION

COMPARISON WITH WOLF-RAYET STARS POPULATION

Constant SF + Salpeter IMF

- WNC/WR in good agreement with observations (semiconvection during core He burning) – MM03 claimed that such an agreement could be achieved only with the inclusion of rotation

- Too many WN predicted compared to WCO

- Too few WR-stars predicted compared to O-type stars

- WR predicted masses higher than the observed ones

Page 11: EVOLUTIONARY PATH TOWARD THE CORE COLLAPSE SUPERNOVA EXPLOSION

MASSIVE STARS: NEUTRINO LOSSES

The Nuclear Luminosity (Lnuc) closely follows the energy losses

nuc

nuc

EL Mt

nuc nucMt EL

Evolutionary times of the advanced burning stages

reduce dramatically

Each burning stage gives about the same Enuc

Surface properties (Mass Loss, Teff, L) do not change anymore

till the explosion

Neutrino losses play a dominant role in the evolution of a massive star beyond core He burning

Page 12: EVOLUTIONARY PATH TOWARD THE CORE COLLAPSE SUPERNOVA EXPLOSION

ADVANCED BURNING STAGES: INTERNAL EVOLUTIONFour major burnings, i.e., carbon, neon,

oxygen and silicon.

Central burning formation of a convective coreCentral exhaustion shell burning convective shell

Local exhaustion shell burning shifts outward in mass convective shell

C

C

CC

He

Ne O

OO

Si

Si

HeH

Page 13: EVOLUTIONARY PATH TOWARD THE CORE COLLAPSE SUPERNOVA EXPLOSION

ADVANCED BURNING STAGES: INTERNAL EVOLUTIONThe details of this behavior (number, timing, mass extension and overlap of convective shells) is mainly driven by the CO

core mass and by its chemical composition (12C, 16O)CO core mass Thermodynamic history

12C, 16O Basic fuel for all the nuclear burning stages after core He burning

At core He exhaustion both the mass and the composition of the CO core scale with the initial mass…

Page 14: EVOLUTIONARY PATH TOWARD THE CORE COLLAPSE SUPERNOVA EXPLOSION

ADVANCED BURNING STAGES: INTERNAL EVOLUTION

C

C

CC

He

NeO

OO

Si

Si

HeH H He

C

He

Ne OO

Si

...hence, the evolutionary behavior scales as well

In general, one to four carbon convective shells and one to three convective shell episodes for each of the neon, oxygen and silicon

burnings occur.

The number of C convective shells decreases as the mass of the CO core increases (not the total mass!) or asthe 12C left over by

core He burning decreases.

Si

Page 15: EVOLUTIONARY PATH TOWARD THE CORE COLLAPSE SUPERNOVA EXPLOSION

PRESUPERNOVA STAR…and also the density structure of the star at the presupernova stage

The final Fe core Masses range between:

In general the higher is the mass of the CO core (the lower is the 12C left over by the core He burning), the more compact is the

structure at the presupernova stage

MFe=1.14-1.80 M

Page 16: EVOLUTIONARY PATH TOWARD THE CORE COLLAPSE SUPERNOVA EXPLOSION

PRESUPERNOVA STARThe complex interplay among the shell nuclear burnings and the timing of the convective zones determines in a direct way the final distribution

of the chemical composition. The mass loss history (RSG/WR) determines in a direct way the kind of CCSN

Page 17: EVOLUTIONARY PATH TOWARD THE CORE COLLAPSE SUPERNOVA EXPLOSION

INDUCED EXPLOSION AND FALLBACK

Fe core

Shock WaveCompression and Heating

Induced Expansion

and Explosion

Initial Remnan

t

Matter Falling Back

Mass Cut

Initial Remnan

t

Final Remnant

Matter Ejected into the ISMEkin1051 erg

Different ways of inducing the explosion

FB depends on the binding energy: the higher is the initial mass the higher is the binding energy

• Piston (Woosley & Weaver)• Thermal Bomb (Nomoto & Umeda)• Kinetic Bomb (Chieffi & Limongi)

Page 18: EVOLUTIONARY PATH TOWARD THE CORE COLLAPSE SUPERNOVA EXPLOSION

THE FINAL FATE OF A MASSIVE STAR

Thorsett & Chakrabarty (1999)

No neutron stars formed by massive progenitors (contrary to recent observational evidences, see Smartt et al. 2009)

Hydrodynamic models based on induced explosions

No (or very few) bright SNIb/c predicted

Page 19: EVOLUTIONARY PATH TOWARD THE CORE COLLAPSE SUPERNOVA EXPLOSION

SUMMARY Maximum mass evolving as a RSG on a substantial fraction of core He burning

Mmax,RSG ~ 35 M

RSG/YSG/BSG SNe as a function of the initial mass

M ≤ 22 M RSG-SN22 M < M ≤ 35 M YSG-SN35 M < M BSG-SN

The minimum masses for the formation of the various kind of Wolf-Rayet stars are:

MWNL ~ 23 M

MWNE ~ 35 M

MWC ~ 45 M

- WNC/WR in good agreement with observations- Too many WN predicted compared to WCO

- WR/O significanlty underestimated compared to observations

- WR predicted masses higher than the observed ones

- Consistent with the maximum luminosity of galactic RSG stars

Page 20: EVOLUTIONARY PATH TOWARD THE CORE COLLAPSE SUPERNOVA EXPLOSION

SUMMARYMaximum mass for SNII-P Mmax,IIP ~ 17 M

- Consistent with the recent observational estimates (Smartt et al. 2009)

Minimum mass for SNIb/c: MSNII/SNIbc ~ 35 M

In principle compatible with the observed rates

The final Fe core Masses range between:

MFe=1.14-1.80 M

The limiting mass between NS and BH froming SNe :

MNS/BH ~ 22 M

in agreement with

Because of the large fallback No (or very few) bright SNIb/c predicted

- Large uncertainties in treatment of the fallback- Mixing and Fallback (Umeda & Nomoto)- Larger energies / Binary channel

Page 21: EVOLUTIONARY PATH TOWARD THE CORE COLLAPSE SUPERNOVA EXPLOSION

PHYSICS OF ROTATIONSTRUCTURE• Oblateness (interior, surface)• New structure equations

Von Zeipel Theorem

Meridional Circulation

Local conservation Meridional circulation

Advection of angular

momentum

Increase the gradient of

angular velocity

Shear Instabiliti

esTransport of Angular Momentum

Transport of Chemical Species

G. Meynet G. Meynet

Page 22: EVOLUTIONARY PATH TOWARD THE CORE COLLAPSE SUPERNOVA EXPLOSION

ROTATING MODELS

Page 23: EVOLUTIONARY PATH TOWARD THE CORE COLLAPSE SUPERNOVA EXPLOSION

THE EFFECT OF ROTATION

- Progressive reduction of the effective gravity from the pole to the equator- Mixing of core nuclear burning products outward and fresh material inward

- Different path in the HRD diagram- Increase of the nuclear burning lifetimes- Increase of the mean molecular weight of the envelope- Different mass loss history- Early entrance in the WR phase Different mass limits and

lifetimes for the various WR stages

Page 24: EVOLUTIONARY PATH TOWARD THE CORE COLLAPSE SUPERNOVA EXPLOSION

THE EFFECT OF ROTATION

- Progressive reduction of the effective gravity from the pole to the equator- Mixing of core nuclear burning products outward and pristine material inward

- Different path in the HRD diagram- Increase of the nuclear burning lifetimes- Different mass loss history- Early entrance in the WR phase Different mass limits and

lifetimes for the various WR stagesNo Rotation

Rotation

Mmin(WNL) 23 17Mmin(WNE) 35 100Mmin(WNC) 50 17Mmin(WCO)

45 35

Page 25: EVOLUTIONARY PATH TOWARD THE CORE COLLAPSE SUPERNOVA EXPLOSION

THE EFFECT OF ROTATION

- Good fit to WR/O- Discrepancies between predicted and observed

WR ratios- Good fit to the WR luminosities

Page 26: EVOLUTIONARY PATH TOWARD THE CORE COLLAPSE SUPERNOVA EXPLOSION

THE EFFECT OF ROTATION

Initial Mass

Final Mass

MH MHe Progenitor

SN

13 12.0 5.46 4.49 RSG II-P15 13.4 5.75 4.90 RSG II-P20 8.1 0.25 3.81 RSG IIb25 10.4 0.14 4.42 YSG IIb30 12.6 0.03 4.35 YSG IIb/Ib40 16.0 0.00 4.22 WNE Ib/c60 16.8 0.00 0.93 WC Ib/c80 22.6 0.00 1.07 WC Ib/c

120 30.8 0.00 1.02 WC Ib/c

NO ROTATIONInitial Mass

Final Mass

MH MHe Progenitor

SN

13 9.54 3.16 2.75 RSG II-P15 8.44 1.76 2.15 RSG II-P20 7.39 0.00 0.74 WNC Ib25 9.25 0.00 0.75 WNC Ib30 11.8 0.00 0.78 WNC Ib40 14.2 0.00 0.57 WC Ib/c60 18.6 0.00 0.45 WC Ib/c80 22.5 0.00 0.45 WC Ib/c

120 22.5 0.00 0.63 WC Ib/c

WITH ROTATION

OK OK

OK Too many SNIb/c

predicted

Page 27: EVOLUTIONARY PATH TOWARD THE CORE COLLAPSE SUPERNOVA EXPLOSION

ROTATING MODELS

Rotational mixing during core He burning brings continuously fresh He from the outer zones into the convective core

substantial reduction of the 12C mass fraction left over by core He burning especially in the less massive stars where this mechanism is more efficient due to their higher He burning lifetimes (80-120

are exceptions)

Page 28: EVOLUTIONARY PATH TOWARD THE CORE COLLAPSE SUPERNOVA EXPLOSION

ROTATING MODELS....hence the behavior of any given rotating star during the more advanced burning stages will resemble that of a non rotating star

having a higher mass (80-120 exceptions)rotating models appear much more compact compared to the non

rotating ones

the iron cores are larger as well and range between

MFe=1.7-2.3 M

Page 29: EVOLUTIONARY PATH TOWARD THE CORE COLLAPSE SUPERNOVA EXPLOSION

THE FINAL FATE OF ROTATING MODELS

Substantially larger than the observed value

No neutron stars formed by massive progenitors (contrary to recent observational evidences, see Smartt et al. 2009)

Hydrodynamic models based on induced explosions

Bright SNIb/c produced by rapid rotation?

Page 30: EVOLUTIONARY PATH TOWARD THE CORE COLLAPSE SUPERNOVA EXPLOSION

EVOLUTION OF THE ANGULAR MOMENTUM

From Core He exhaustion onward the evolution of the angular momentum is dominated by the local conservation and by the

convective mixing

During core H burning the angular momentum transport is dominated by the meridional circulation and by mass loss – the relative efficiency

depending on the initial mass

Page 31: EVOLUTIONARY PATH TOWARD THE CORE COLLAPSE SUPERNOVA EXPLOSION

IMPLICATIONS FOR YOUNG PULSARS AND GRBsIf the hydrodynamical simulations are wrong and we assume that all the

stars would collapse to a NS with a mass corresponding roughly to the Iron Core Mass and a Radius of 12 Km

These models have even much more angular momentum in the collapsing iron core than a neutron star can possibly carry

Treatment of angular momentum transport still highly uncertain (advection/diffusion, transport mechanisms and

their efficiency) should be revisedImportant the role of magnetic field (see Heger et al. 2005)

Page 32: EVOLUTIONARY PATH TOWARD THE CORE COLLAPSE SUPERNOVA EXPLOSION

If the large angular momenta obtained for the iron cores in this work may pose a problem for pulsars, they are very favorable

for the GRBs

IMPLICATIONS FOR YOUNG PULSARS AND GRBs

minimum value needed to make a long GRB by magnetar or collapsar formation (Burrows

et al. 2007)

These models imply that all WR stars can retain enough angular momentum to produce GRBs, either by magnetar or collapsar formation

depending on the final mass. This gives a nearly 1000 times higher ratio of GRBs to SNe than the observationally implied value.

Page 33: EVOLUTIONARY PATH TOWARD THE CORE COLLAPSE SUPERNOVA EXPLOSION

The inclusion of a more efficient mass loss during the RSG phase (dust driven wind) lowers the maximum mass for SN-IIP from ~ 30 M (old models) to ~ 17 M without changing the maximum mass

evolving as RSG, independent of rotationThe inclusion of rotation reduces the minimum mass that become a WR star from ~ 22 M (non rotating models) to ~ 17 M and the

minimum masses for all the various WR stages and also the minimum mass for SNIb/c from ~ 30 M (non rotating models) to

~ 17 M - Improve the fit to WR/O and to WR luminosities- Discrepancies between predicted and observed WR

ratios still remain - Sharp transition from SNIIP to SNIb - too many

SNIb/c predictedRotating models are much more compact and with larger iron cores

than the non rotating ones- Implications for CCSN explosion simulations- Average mass of NS remnant larger than observed- Lowering of the MNS/BH from 22 to 14 (simulated

explosion uncertain)The angular momentum of the core of rotating models is too large:

- NS remnants rotating too fast

- GRB/SN ratio severely overestimated

SUMMARY