A few Challenges in massive star evolution ROTATIONMAGNETIC 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%v crit 6-7% 50-70%

+ Limongi & Chieffi M sol, solar Z No internal magnetic field + Ekström et al. (2012) No internal magnetic field + Georgy et al. (2012; 2013) No internal magnetic field Rotating models With and without Dynamo.

Mixed modes in the red giant KIC (0.84 M sol, [Fe/H]=-1)  Rotational splittings for 18 modes (Deheuvels et al. 2012)  Inversion of the rotation profile: Deheuvels et al Asteroseismology of red giants Ceillier et al  c = 710 ± 51 nHz (innermost 1.4% in r)  s < 150 ± 19 nHz OBSERVATIONMODELS V ini = 2 km s -1 shellular Solid X c =0.1 Solid X c =0 Nano Hertz Micro Hertz ADDITIONAL MECHANISM OPERATING DURING THE HR CROSSING

Levesque et al Upper luminosity Of SNIIP progenitors Tracks from Ekström et al RSG=End Point RSG≠End Point 3) Where are the progenitors of the luminous type IIP SN ?

Smartt ) Which stars are the progenitors the type Ibc supenovae?

Jose Groh - The surprising look of massive stars before death

Smartt ) Which stars are the progenitors the type Ibc supenovae?

Jose Groh - The surprising look of massive stars before death

Why so few detections of type Ibc progenitors? ~13 archives images, only one detection Pre SN are WO stars not WN or WC stars Too low L for being detected Groh et al, A&A in press; Yoon et al Models Observed upper limit

THE ONLY PROGENITOR DETECTED SO FAR FOR A TYPE Ibc: iPTF13bvn Cao et al Models Obs of iPTF13bvn Groh et al …QUITE WELL EXPLAINED BY THEORY OF SINGLE STARS

Jose Groh - The surprising look of massive stars before death Observed rates Eldridge et al 2013 Smith et al 2012

Rotating models with no internal magnetic field Pre SN For NS with P=20mms For NS at break-up Woosley 2003 Z sol 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 M sun, Z=0.014, V ini /V crit =0.4 A SMALL FAST SPINNING CORE IMMERGED IN A SLOWLY ROTATING ENVELOPE TOTAL ANGULAR MOMENTUM: (10 50 cm 2 g -1 ) 12.0 ANGULAR MOMENTUM IN THE ENVELOPE: 4.3 ANGULAR 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 is 0.04 km s -1 critical velocity At the surface is About 16 km s -1 If envelope absorb L core increase of only 23% of the surface velocity A COUPLING EFFICIENT ENOUGH BETWEEN THE CORE AND THE ENVELOPE WOULD HAVE A STRONG IMPACT ON THE ANGULAR MOMENTUM OF THE CORE WITHOUT CHANGING TO MUCH THE ANGULAR MOMENTUM OF THE ENVELOPE M r /M sun

THE DIFFICULTY HOW TO RECONCILE THE LOSS OF LARGE AMOUNT OF MASS (H-RICH ENVELOPE REMOVED) WITH FAST ROTATING CORE? POSSIBLE SOLUTIONS STARS BECOME H-POOR BY EVOLVING HOMOGENEOUSLY THE ANGULAR MOMENTUM TRANSPORT BETWEEN CORE AND ENVELOPE REMAINS MODEST AT EVERY TIME PREDICTIONS AND IMPLICATIONS ARE DIFFERENT HOMOGENEOUS EVOLUTIONDIFFERENTIAL ROTATION Only very fast rotators at low Z GRB/CC ~ 2% at Z=0.002, 5% at Z= Moderate rotators and Ic only when (C+O >He) GRB/CC ~ 7% at Z=0.004, Moderately rotating stars are also solid body rotating on MS  Rotation of pulsars Yoon et al (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 Shellular rotation MOST OF MASS SPHERICAL DISTRIBUTION MOST OF MASS SPHERICAL DISTRIBUTION 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 I bc or BH Massive star evolution (at solar Z, above 30 M ) OB-type 85M ☉ LBV Wolf-Rayet ☉ So far, no observations of WRs as SN progenitors (Smartt 09)

5) ROTATION AND PROGENITORS OF LONG SOFT GAMMA RAY BURSTS

Jose Groh - The surprising look of massive stars before death