The Impact of Mass Loss Bin C osmos on the Final Structure - PowerPoint PPT Presentation

Anton Pannekoek Institute Binary Stars in Cambridge The Impact of Mass Loss Bin C osmos on the Final Structure Mathieu Renzo and Fate of PhD in Amsterdam Massive Stars Collaborators: C. D. Ott, S. N. Shore, S. E. de Mink, E. Zapartas, Y. G¨ otberg, C. J. Neijssel, A. Piro, V. Morozova 1 / 18

Anton Pannekoek Institute Outline Possible Mass Loss Channels • Radiatively Driven Stellar Winds • Roche Lobe Overflow • Impulsive Events Effect of Winds on the Late Stellar Structure • pre-SN Mass • Core Structure & “Explodability” Light Curves from post-Impulsive Mass Loss • Numerical Experiment of Stripping • Pre-SN Stripped Structures • Resulting Lightcurves Conclusions 2 / 18

Anton Pannekoek Institute Radiatively Driven Winds in One Slide Problems: High Non-Linearity and Clumpiness: = � ρ 2 � def � ρ � 2 � = 1 ⇒ Inhomogeneities ⇒ ˙ M < 4 π r 2 ρ v ( r ) f cl 3 / 18

Anton Pannekoek Institute Massive Stars Come in Binaries Up to ∼ 70% of Massive Stars will interact with their companion (e.g. Mason et al. ’09, Sana & Evans ’12, Sana et al. ’12, Kobulnicky et al. ’14) 4 / 18

Anton Pannekoek Institute Impulsive Mass Loss Event “Dynamical Instabilities” ⇐ LBVs, Pulsations, Super-Eddington Winds, Centrifugal Disk Shedding, Common Envelope Ejection (Possibly triggered by η Car, Credits: NASA/ESA Mass Accretion in a Binary) 5 / 18

Anton Pannekoek Institute Outline Possible Mass Loss Channels • Radiatively Driven Stellar Winds • Roche Lobe Overflow • Impulsive Events Effect of Winds on the Late Stellar Structure • pre-SN Mass • Core Structure & “Explodability” Light Curves from post-Impulsive Mass Loss • Numerical Experiment of Stripping • Pre-SN Stripped Structures • Resulting Lightcurves Conclusions 6 / 18

Anton Pannekoek Institute Impact on the Final Mass Legend: • η = 0 . 1 x η = 0 . 33 + η = 1 . 0 η → largest uncertainty Renzo et al. , in prep. 7 / 18

Anton Pannekoek Institute Impact on the Final Mass Impossible to map: Legend: M f ≡ M f ( M ZAMS ) • η = 0 . 1 x η = 0 . 33 + η = 1 . 0 Just because of winds! η → largest uncertainty Renzo et al. , in prep. 7 / 18

Anton Pannekoek Institute “Explodability” & Compactness Parameter def M / M ⊙ ξ M ( t ) = R ( M ) / 1000 km • “Large” ξ 2 . 5 ⇒ harder to explode ⇒ BH formation • “Small” ξ 2 . 5 ⇒ easier to explode ⇒ NS formation (e.g. O’Connor & Ott 2011, Ugliano et al. 2012, Sukhbold & Woosley 2014) M = 2 . 5 M ⊙ not to scale! R ( M ) R ( M ) 8 / 18

Anton Pannekoek Institute Core Structure @ O depletion M ZAMS = 25 M ⊙ models Renzo et al. , in prep. Critical point: Ne core burning/C shell burning Challenges: Nuclear Network & Spatial Resolution 9 / 18

Anton Pannekoek Institute ξ 2 . 5 @ Oxygen Depletion Renzo et al. , in prep. 10 / 18

Anton Pannekoek Institute ξ 2 . 5 @ Oxygen Depletion Legend: • η = 0 . 1 x η = 0 . 33 + η = 1 . 0 Post O burning evolution ⇐ Core contraction ⇐ Amplification of the differences. Renzo et al. , in prep. 11 / 18

Anton Pannekoek Institute Outline Possible Mass Loss Channels • Radiatively Driven Stellar Winds • Roche Lobe Overflow • Impulsive Events Effect of Winds on the Late Stellar Structure • pre-SN Mass • Core Structure & “Explodability” Light Curves from post-Impulsive Mass Loss • Numerical Experiment of Stripping • Pre-SN Stripped Structures • Resulting Lightcurves Conclusions 12 / 18

Anton Pannekoek Institute The Stripping Process 5.2 unstripped 5.1 M = 15 M ⊙ , Z = Z ⊙ 5.0 MCE 4.9 log 10 ( L / L ⊙ ) 4.8 4.7 4.6 mSGB 4.5 4.4 4.3 hMR 4.2 4.5 4.4 4.3 4.2 4.1 4.0 3.9 3.8 3.7 3.6 log 10 ( T eff / [ K ]) Remove mass in steps of 1 M ⊙ , max { ∆ M impulsive } = 7 M ⊙ . Morozova et al. 2015 – ApJ,814,63M 13 / 18

Anton Pannekoek Institute Pre-SN Stripped Structures Morozova et al. 2015 – ApJ,814,63M 14 / 18

Anton Pannekoek Institute Pre-SN Stripped Structures Morozova et al. 2015 – ApJ,814,63M 15 / 18

Institute Anton Pannekoek Light Curves from Stripped Models Comparison of three progenitor grids 43 Morozova et al. 2015 – ApJ,814,63M mSGB hMR log 10 L [erg s − 1 ] MCE 1 M ⊙ stripped 2 M ⊙ stripped 3 M ⊙ stripped 42 4 M ⊙ stripped 5 M ⊙ stripped 6 M ⊙ stripped 7 M ⊙ stripped 0 50 100 Time [days] SNEC 16 / 18

Anton Pannekoek Institute Outline Possible Mass Loss Channels • Radiatively Driven Stellar Winds • Roche Lobe Overflow • Impulsive Events Effect of Winds on the Late Stellar Structure • pre-SN Mass • Core Structure & “Explodability” Light Curves from post-Impulsive Mass Loss • Numerical Experiment of Stripping • Pre-SN Stripped Structures • Resulting Lightcurves Conclusions 17 / 18

Anton Pannekoek Institute Summary • Systematic uncertainties in modeling mass loss: – pre-explosion mass ⇒ no M f ≡ M f ( M ZAMS ) map; ⇒ “explodability”; – core density profile – surface abundances ⇒ SN spectrum and type. Role of Binaries: • Observational constraints ⇒ colliding winds; • Possibly cause of mass loss (RLOF, CE, accretor); • RLOF can leave some H-rich material ⇒ role in SNIIL? 18 / 18

Anton Pannekoek Institute Summary • Systematic uncertainties in modeling mass loss: – pre-explosion mass ⇒ no M f ≡ M f ( M ZAMS ) map; ⇒ “explodability”; – core density profile – surface abundances ⇒ SN spectrum and type. Role of Binaries: • Observational constraints ⇒ colliding winds; • Possibly cause of mass loss (RLOF, CE, accretor); • RLOF can leave some H-rich material ⇒ role in SNIIL? Thank you! 18 / 18

Anton Pannekoek Institute Outline Backup slides 19 / 18

Anton Pannekoek Institute Mass Loss in (Semi–)Empirical parametric models. Uncertainties encapsulated in efficiency factor: ˙ M ( L , T eff , Z , R , M , ... ) ⇐ η ˙ M ( L , T eff , Z , R , M , ... ) η is a free parameter: η ∈ [ 0 , + ∞ ) Figure: From Smith 2014, ARA&A, 52, 487S 20 / 18

Anton Pannekoek Institute Different dM / dt algorithms with Grid of Z ⊙ ≃ 0 . 019, non-rotating stellar models: • Initial mass: M ZAMS = { 15 , 20 , 25 , 30 , 35 } M ⊙ ; • Efficiency: η ≡ √ f cl = { 1 , 1 1 10 } ; 3 , • Different combinations of wind mass loss rates for “hot” ( T eff ≥ 15 [ kK ] ), “cool” ( T eff < 15 [ kK ] ) and WR stars: Kudritzki et al. ’89; Vink et al. ’00, ’01; Van Loon et al. ’05; Nieuwenhuijzen et al. ’90; De Jager et al. ’88; Nugis & Lamers ’00; Hamann et al. ’98. 21 / 18

Anton Pannekoek Institute Core Structure @ O depletion M ZAMS = 25 M ⊙ models Critical point: Ne core burning/C shell burning 22 / 18

Anton Pannekoek Institute Wind Oservational Diagnostics • P Cygni line profiles Back • Optical and near UV lines (e.g. H α ) • Radio and IR continuum excess • IR spectrum of molecules (e.g. CO) • Maser lines (for low density winds) Assumptions commonly needed: � β � 1 − r • Velocity structure: v ( r ) ≃ with β ≃ 1 R ∗ • Chemical composition and ionization fraction • Spherical symmetry: ˙ M = 4 π r 2 ρ v ( r ) • Steadiness and (often) homogeneity ˙ M derived from fit of (a few) spectral lines. No theoretical guaranties coefficients are constant. 23 / 18

Anton Pannekoek Institute Wolf-Rayet Stars Back Observational Definition: Based on spectral features indicating a Strong Wind : • Hydrogen Depletion ( � = Lack of Hydrogen) • Broad Emission Lines • Steep Velocity Gradients Sub-categories: WN,WC,WO,WNL, etc. Computational Definition ( ): • X s < 0 . 4 Impossible to distinguish sub-categories without spectra! 24 / 18

Anton Pannekoek Institute Chosen Stripping Points 5.2 unstripped 5.1 M = 15 M ⊙ , Z = Z ⊙ 5.0 MCE 4.9 log 10 ( L / L ⊙ ) 4.8 4.7 4.6 mSGB 4.5 4.4 4.3 hMR 4.2 4.5 4.4 4.3 4.2 4.1 4.0 3.9 3.8 3.7 3.6 log 10 ( T eff / [ K ]) t ( MCE ) − t ( mSGB ) ≃ 10 4 [ yr ] ≪ 14 . 13 × 10 6 [ yr ] 25 / 18