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A few Challenges in massive star evolution
ROTATION MAGNETIC FIELD MULTIPLICITY
How do these distributions vary with metallicity?
How do these distributions vary with the environment? (e.g. stellar density)
What is the origin of these distributions
What are the impacts on the interior?
40%vcrit
6-7%50-70%
+ Limongi & Chieffi 2013 13-120 Msol, solar ZNo internal magnetic field
+ Ekström et al. (2012)No internal magnetic field
+ Georgy et al. (2012; 2013)No internal magnetic field
Rotating models
With and withoutDynamo.
Mixed modes in the red giant KIC 7341231 (0.84 Msol, [Fe/H]=-1)
Rotational splittings for 18 modes (Deheuvels et al. 2012)Inversion of the rotation profile:
Deheuvels et al. 2012
Asteroseismology of red giantsAsteroseismology of red giants
Ceillier et al. 2013
c = 710 ± 51 nHz (innermost 1.4% in r)
s < 150 ± 19 nHz
OBSERVATION MODELS
Vini= 2 km s-1
shellular
Solid Xc=0.1
Solid Xc=0
Nano Hertz Micro Hertz
ADDITIONAL MECHANISM OPERATING DURING THE HR CROSSING
Levesque et al. 2005
Upper luminosityOf SNIIP progenitors
Tracks from Ekström et al. 2012
RSG=End Point
RSG≠End Point
3) Where are the progenitors of the luminous type IIP SN ?
Jose Groh - The surprising look of massive stars before death Smartt 2009
4) Which stars are the progenitors the type Ibc supenovae?
Why so few detections of type Ibc progenitors? ~13 archives images, only one detection
Pre SN are WO stars not WN or WC starsToo low L for being detected
Groh et al, A&A in press; Yoon et al. 2012
Models
Observed upper limit
THE ONLY PROGENITOR DETECTED SO FAR FOR A TYPE Ibc: iPTF13bvn Cao et al. 2013
Models
Obs of iPTF13bvn
Groh et al. 2013 …QUITE WELL EXPLAINED BY THEORY OF SINGLE STARS
Jose Groh - The surprising look of massive stars before death
43-62
12-22
6-12
13-22
Observed rates Eldridge et al 2013Smith et al 2012
Rotating models with no internal magnetic field
Pre SN
For NS with P=20mms
For NS at break-upWoosley 2003
Zsol
WR
DO MASSIVE STARS ROTATE LIKE SOLID BODIES ON THE MS?
MAGNETIC FIELDS MAY ACTUALLY BE INVOLVED IN A DIFFERENT WAY
MAGNETIC BRAKING AT THE SURFACE
MAGNETIC BRAKING OF THE STELLAR CORES
LONG GRB MAY THEN OCCUR IN SITUATIONS WHERE THESE MAGNETIC BRAKING PROCESSES ARE NOT PRESENT
FAST ROTATORS AVOIDING THE RED SUPERGIANT PHASE?
HOW A RSG ROTATE IN THE INTERIOR? (SHELLULAR MODEL, NO MAGNETIC FIELD, SOLID BODY ROTATION IN CC)?
15 Msun, Z=0.014, Vini/Vcrit=0.4
A SMALL FAST SPINNING CORE IMMERGED IN A SLOWLY ROTATING ENVELOPE
TOTAL ANGULAR MOMENTUM: (1050 cm2g-1) 12.0ANGULAR MOMENTUM IN THE ENVELOPE: 4.3ANGULAR MOMENTUM IN THE CORE: 1.0
Pulsar rotation estimated from conservation of angular momentum in the central 2 Msun:
9.2e-5 s, a period 217 times smaller than 20 ms
Surface velocity is0.04 km s-1
critical velocityAt the surface isAbout 16 km s-1
If envelope absorb Lcore
increase of only 23% of the surface velocity
A COUPLING EFFICIENT ENOUGH BETWEEN THE CORE AND THE ENVELOPE WOULD HAVEA STRONG IMPACT ON THE ANGULAR MOMENTUM OF THE CORE WITHOUT CHANGING
TO MUCH THE ANGULAR MOMENTUM OF THE ENVELOPE
Mr/Msun
THE DIFFICULTYHOW TO RECONCILE THE LOSS OF LARGE AMOUNT OF MASS (H-RICH ENVELOPE REMOVED)
WITH FAST ROTATING CORE?
POSSIBLE SOLUTIONSSTARS BECOME H-POOR BY EVOLVING HOMOGENEOUSLY
THE ANGULAR MOMENTUM TRANSPORT BETWEEN CORE AND ENVELOPEREMAINS MODEST AT EVERY TIME
PREDICTIONS AND IMPLICATIONS ARE DIFFERENTHOMOGENEOUS EVOLUTION DIFFERENTIAL ROTATION
Only very fast rotators at low Z
GRB/CC ~ 2% at Z=0.002, 5% at Z=0.00001
Moderate rotators and Ic only when (C+O >He)
GRB/CC ~ 7% at Z=0.004, 0.008
Moderately rotating stars are also solid body rotating on MS Rotation of pulsars
Yoon et al. 2006 (interior magnetic field)
(No interior magnetic fields)
Asteroseismology?
need braking mechanisms to explain rotation of pulsars
Hirschi et al. 2005; Georgy et al. 2009, 2012
Core braking mechanism?
WEAK WR WINDS AT LOW Z NEEDED
Roche approximation
Shellularrotation
MOST OF MASS
SPHERICALDISTRIBUTION
MOST OF MASS
SPHERICALDISTRIBUTION
EQUATIONS FOR MEAN VALUES ON ISOBARS
ON ISOBARS DIFFERENCE WITH RESPECT TO MEAN VALUES SMALL (LEGENDRE)
1.5D
Numerical treatment of the meridional circulation
Treatment of the ``mixing blocking effect’’ of mu-gradients
Choice of the diffusion coefficient
Inclusion of a dynamo in radiative zone
Inclusion of internal waves
Inclusion of anisotropic winds
Inclusion of magnetic braking by the winds
Jose Groh - The surprising look of massive stars before death (after evol. tracks from Meynet & Maeder 03, Ekstrom+ 12)
OB-type LBV WR SN Ibc or BH
Massive star evolution (at solar Z, above 30 Massive star evolution (at solar Z, above 30 M )M )
OB-type
85M ☉
LBVWolf-Rayet
☉
So far, no observations of WRs as SN progenitors (Smartt 09)