the effect of rotation on the hydrostatic and explosive yields of massive stars

THE EFFECT OF ROTATION ON THE HYDROSTATIC AND

EXPLOSIVE YIELDS OF MASSIVE STARS

and

Alessandro ChieffiINAF – Istituto di Astrofisica e Planetologia Spaziali, Italy

Centre for Stellar and Planetary Astrophysics, Monash Univesity, [email protected]

Marco LimongiINAF – Osservatorio Astronomico di Roma, ITALY

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

HYDROSTATIC AND EXPLOSIVE YIELDS OF MASSIVE STARS

mass cut

Remnant Ejecta


Element Production Site

N (14N) Hydrostatic H burningF (19F) Hydrostatic He convective shell

C (12C)O (16O)

Hydrostatic core He burning(16O partially modified by Cshell and Nex)

Ne (20Ne) Na (23Na)Mg (24Mg) Al (27Al)

Hydrostatic C convective shellPartially destroyed by Cx (23Na) and Nex (20Ne)Partially produced by Nex (24Mg,27Al)

P (31P) Nex

Cl (35Cl, 37Cl) Nex+Ox

K (39K) Ox

Sc (45Sc) Hydrostatic C convective shellNex+Ox

Si (28Si) S (32S)Ar (36Ar) Ca (40Ca)

Ox+Sii

V (51Cr)Cr (52Cr,52Fe)Mn (55Mn,55Co)

Sii

Ti (48Cr) Ox+Sii+SicFe (56Ni)Co (59Co,59Ni)Ni (58Ni,60Ni)

Sic

mass cut

Remnant Ejecta

HYDROSTATIC AND EXPLOSIVE YIELDS OF MASSIVE STARSHydrostatic Yields mainly depend on the presupernova evolution

(convective history, diffusive mixing, core masses, mass loss)

Each zone keeps track of the various central or shell, convective and/or ratidative, burning

C

C

CC

He

NeO

OO

Si

Si

HeH

Explosive Yields mainly depend on the presupernova chemical and density structure

Complete Si burning

Incomplete Si burning

Explosive O burning

Explosive Ne burning

Explosive C burning

No M

odifi

catio

n

NSE

Sc Ti FeCo Ni

QSE 1 Clusters

Cr V Mn

QSE 2 Cluster

Si S ArK Ca

Mg Al

P Cl

Ne Na

3700 5000 6400 11750 13400RADIUS (Km)

Mass-Radius relation, Ye profile, Chemical Stratification @ Presupernova Stage

Complete Si burning

Incomplete Si burning

Explosive O burning

Explosive Ne burning

Explosive C burning

No M

odifi

catio

n

NSE

Sc Ti FeCo Ni

QSE 1 Clusters

Cr V Mn

QSE 2 Cluster

Si S ArK Ca

Mg Al

P Cl

Ne Na

INTERIOR MASS


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 (ML & Chieffi 2003) and 5.0 (ML &

Chieffi 2006)- FULL COUPLING of: Physical Structure - Nuclear Burning -

Chemical Mixing (convection, semiconvection, rotation)- INCLUSION OF ROTATION:

- Conservative rotation law/Shellular Rotation (Meynet & Maeder 1997)

- Transport of Angular Momentum (Advection/Diffusion, Maynet & Maeder 2000)

- 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

FRANEC 6.0

(Chieffi & ML in prep.)

(Coupled and solved simultaneously)

(4th order 4 ODE soved by means of a relaxation method)or

INFLUENCE OF ROTATION ON CORE H BURNING

Almost same H exhausted core @ core H depletion (exception for M=120 M)Shallower chemical profiles in rotating models due to rotationally induced mixing

Different path in the HR diagram different mass loss history Mass Loss does not scale monotonically with rotation

INFLUENCE OF ROTATION ON CORE H BURNING

H-rich envelope enriched by core H burning products

M≤60 M : Rotational mixing dominates

Rotational induced mixing beyond the He convective core

Reduced m-gradient barrier larger convective cores

INFLUENCE OF ROTATION ON CORE AND SHELL He BURNING

v=0 km/s

v=300 km/s



Reduced m-gradient barrier larger convective coresLarger CO coresContinuous inward mixing of fresh 4He fuel Lower 12C left over at core He depletion


v=0 km/s

v=300 km/s



Reduced m-gradient barrier larger convective coresLarger CO coresContinuous inward mixing of fresh 4He fuel Lower 12C left over at core He depletionFormation of He convective shell in the region of variable He He convective shell hotter more 12C and 16O produced locally

Rotating and Non Rotating models show completely different structures


v=0 km/s

v=300 km/s

M>60 M : Mass Loss dominates

Mass Loss uncovers the He core at the beginning of Core He burning


v=0 km/s

v=300 km/s



He convective core progressively recedes in mass and leaves a region of variable He


v=0 km/s

v=300 km/s



He convective core progressively recedes in mass and leaves a region of variable HeIn these stars this region is not due to the rotationally induced mixing but to the efficient mass loss that progressively erodes the He core


v=0 km/s

v=300 km/s



He convective core progressively recedes in mass and leaves a region of variable HeIn these stars this region is not due to the rotationally induced mixing but to the efficient mass loss that progressively erodes the He coreFormation of He convective shell in the region of variable He in both rotating and non rotating models

Rotating and Non Rotating models show similar structures


v=0 km/s

v=300 km/s

ADVANCED BURNING STAGES: INTERNAL EVOLUTION OF ROTATING AND NON ROTATING STARS

Properties of the CO core at Core C-ignition

Differences progressively reduce with the initial mass

Rotating models show larger CO cores and smaller 12C mass fractions at core He depletion compared to the non

rotating ones

ADVANCED BURNING STAGES: INTERNAL EVOLUTIONFour major burning, 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

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…

v=0 km/s

v=0 km/s

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

burning occur.

Basic rule: the larger is the CO core, the lower is the 12C at core He exhaustion. the less efficient is the C burning shell, the lower is the

number of convective episodes

Si

PRESUPERNOVA STAR

The higher is the mass of the CO core (the lower is the 12C at the core He exhaustion ), the more compact is the structure at the presupernova

stage

v=0 km/sv=0 km/s

Less efficient C shell burning means stronger contraction of the CO core

ADVANCED BURNING STAGES: INTERNAL EVOLUTION OF ROTATING AND NON ROTATING STARS

Properties of the CO core at Core C-ignition

Differences progressively reduce with the initial mass

Rotating models show larger CO cores and smaller 12C mass fraction at core He depletion compared to the non

rotating ones

PRESUPERNOVA MODELS: ROTATING vs NON ROTATING STARS

....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)Presupernova rotating models appear much more compact compared to the non rotating ones and with larger Fe cores

Rotating models have a larger binding energy compared to the non rotating ones

PRESUPERNOVA MODELS: ROTATING vs NON ROTATING STARS

THE FINAL FATEHydrodynamical simulations based on induced explosions for Eexpl=1051 erg

(ML & Chieffi 2003, Chieffi & ML 2012 in prep)

Larger binding energies Larger fallback masses after the explosion Rotating models less efficient in polluting the ISM with heavy

elements

Difficult to compare the ejected masses in this case

In both cases no, or very few, heavy elements ejected for models with M>20 M

EJECTED MASSES: COMPARISONCo

mpa

rison

mad

e fo

r a fi

xed

amou

nt o

f 56 N

i eje

cted

• Differences confined with a factor of 2 for the majority of the elements


mpa

rison

mad

e fo

r a fi

xed

amou

nt o

f 56 N

i eje

cted

• Differences confined with a factor of 2 for the majority of the elements• Overproduction of C and O in low-mass rotating models


mpa

rison

mad

e fo

r a fi

xed

amou

nt o

f 56 N

i eje

cted

• Differences confined with a factor of 2 for the majority of the elements• Overproduction of C and O in low-mass rotating models• Overproduction of F in rotating models with mass 20-40 M


mpa

rison

mad

e fo

r a fi

xed

amou

nt o

f 56 N

i eje

cted

• Differences confined with a factor of 2 for the majority of the elements• Overproduction of C and O in low-mass rotating models• Overproduction of F in rotating models with mass 20-40 M• Overproduction of Si-Sc elements in rotating models with mass ~ 20-25

M


mpa

rison

mad

e fo

r a fi

xed

amou

nt o

f 56 N

i eje

cted

• Differences confined with a factor of 2 for the majority of the elements• Overproduction of C and O in low-mass rotating models• Overproduction of F in rotating models with mass 20-40 M• Overproduction of Si-Sc elements in rotating models with mass ~ 13-25

M• Overproduction of s-process elements in rotating models with mass 20-

40 M

Element

Production Site Ejected Mass Ratio

(Rot/No Rot)

Reason

C Hydrostatic Core and Shell He burning

~3-2 for M<30 M Larger CO cores/Hotter He convective shells(In spite of the lower 12C left by core He burning)

O Hydrostatic Core He burning

~5-2 for M<25 M Larger CO cores/Larger 16O left by Core He burning

F Hydrostatic He convective shell

~20 around M=30 M

Hotter He convective shell

Si-Sc Explosive burning ~2 for M<30 M More compact PreSN structure more mass synthesized by all the explosive burning

s-process

Hydrostatic Core He burning and Hydrostatic Convective C burning

~7 around M=30 M

Longer He burning lifetimesLarger He convective coresHotter C convective shell

EJECTED MASSES: COMPARISON

Rotating models produce more metals compared to the non rotating ones because of the larger CO cores and more

compact structures

ENRICHMENT OF THE INTERSTELLAR MEDIUM

Differences reduce with the mass

56Ni=0.1 M

PRODUCTION FACTORS

SUMMARY AND CONCLUSIONS

Influence of rotation on the presupernova evolution (from the point of view of the hydrostatic and explosive yields)

Negligible effect on the H exhausted core @ core H depletionLarger CO cores and smaller 12C mass fractions @ core He depletion Differences progressively reduced with the initial massPresupernova models more compact and with larger Fe cores Larger binding energiesLarger fallback masses less efficient enrichment of heavy elements for low explosion energiesDifferences in the final yields confined within a factor of ~2 for the majority of the elementsOverproduction of C and O more pronounced in the low-mass modelsOverproduction of Si-Sc elements in models with mass ~ 20-25 MOverproduction of F and s-process elements in models with mass ~ 20-40 MF and s-process elments distribution closer to the solar one in stars with mass ~ 25-40 M

the effect of rotation on the hydrostatic and explosive yields of massive stars

Documents

presupernova chemical

presupernova physical

coupling of rotation

rotation inclusion

massive star2hydrostatic

effect of rotation

convective shellc

massradius relation