Stellar Rotation II

Lecture Given at MESA School 2012

Transcript

1. Stellar Rotation II Matteo Cantiello Kavli Institute for Theoretical Physics (University of California Santa Barbara) Brott et al. 2011
2. Magnetic fields § Spruit-Tayler Dynamo (Spruit 2002) § Core - Envelope coupling 1. Differential rotation winds up toroidal component of B 2. Magnetic torques tend to restore rigid rotation Convective Core If the envelope slows down angular momentum is also removed from the core NS & GRBs 2009 (ﺓةﻱيﺭرﺩدﻥنﻙكﺱسﺇإﻝلﺍا - Alexandria) Matteo Cantiello Long GRB Progenitors Fireworks 2009 (Bonn) Matteo Cantiello Long GRB Progenitors Leicester 2009 Matteo Cantiello Long GRB Progenitors Stockholm 2009 Matteo Cantiello Long GRB Progenitors Sedgwick 2011 Matteo Cantiello Long GRB Progenitors CfA 2012 Matteo Cantiello Long GRB Progenitors UCSB 2012 Matteo Cantiello MESA School
3. Stockholm 2009 Matteo Cantiello Long GRB Progenitors Debate on the ST Dynamo Sedgwick 2011 Matteo Cantiello Long GRB Progenitors CfA 2012 Matteo Cantiello Long GRB Progenitors UCSB 2012 Matteo Cantiello MESA School § The ST dynamo is still under review § While the Tayler instability is sound, the loop proposed by Spruit has been criticized § Simulations of Zahn et al. 2007 could not find dynamo action § On the other hand simulations of Braithwaite et al. 2006 showed the Spruit-Tayler dynamo § The jury is still out, but it looks like a j-transport mechanism similar to the ST has to work in stars to reproduce some observations (e.g. asteroseismology and spin rates of compact remnants. g-waves could also play a role)
4. Stockholm 2009 Matteo Cantiello Long GRB Progenitors Debate on the ST Dynamo Sedgwick 2011 Matteo Cantiello Long GRB Progenitors CfA 2012 Matteo Cantiello Long GRB Progenitors UCSB 2012 Matteo Cantiello MESA School § The ST dynamo is still under review § While the Tayler instability is sound, the loop proposed by Spruit has been criticized § Simulations of Zahn et al. 2007 could not find dynamo action § On the other hand simulations of Braithwaite et al. 2006 showed the Spruit-Tayler dynamo § The jury is still out, but it looks like a j-transport mechanism similar to the ST has to work in stars to reproduce some observations (e.g. asteroseismology and spin rates of compact remnants. g-waves could also play a role) ! set to 0 for non-magnetic D_ST_factor = 1.0 nu_ST_factor = 1.0
5. § Spin of compact remnants (Heger et al. 2005, Suijs et al. 2008) § Core-envelope coupling leads to spin-down of the core Convective Core Stockholm 2009 Matteo Cantiello Long GRB Progenitors Magnetic fields Sedgwick 2011 Matteo Cantiello Long GRB Progenitors CfA 2012 Matteo Cantiello Long GRB Progenitors UCSB 2012 Matteo Cantiello MESA School
6. Stockholm 2009 Matteo Cantiello Long GRB Progenitors Need for an extra j-transport mechanism Sedgwick 2011 Matteo Cantiello Long GRB Progenitors CfA 2012 Matteo Cantiello Long GRB Progenitors UCSB 2012 Matteo Cantiello MESA School Langer 2012
7. Assignment: Rotation I
8. Results for 15 Msun
9. No Taylor - Spruit Results for 15 Msun
10. C age(yrs) steps zones computing time ----------------------------------------------- 0.25 1.3250E+07 3628 3435 3806s 0.5 1.3253E+07 1863 1723 1110s 0.75 1.3253E+07 1207 1162 590s 1.0 1.2803E+07 466 905 285s 2.0 1.2816E+07 96 499 61s 3.0 1.2657E+07 53 361 37s 4.0 1.2694E+07 43 310 33s ------------------------------------------------------------------------------------- mesh_delta_coeff = (1*C) varcontrol_target = (1d-4*C) Convergence 15 Msun
11. Convergence 15 Msun
12. Convergence 15 Msun
13. Convergence 15 Msun
14. Evolutionary effects
15. Impact of rotation § Changes in luminosity (size of the core, mean molecular weight) § Lifetimes (size of the core) § Surface abundances (Li, B, N, He...) § Mass-loss § e.g. WR/O ratio, Red to Blue SG, SN type § Final angular momentum § SN type § GRB NS & GRBs 2009 (ﺓةﻱيﺭرﺩدﻥنﻙكﺱسﺇإﻝلﺍا - Alexandria) Matteo Cantiello Long GRB Progenitors Fireworks 2009 (Bonn) Matteo Cantiello Long GRB Progenitors Leicester 2009 Matteo Cantiello Long GRB Progenitors Stockholm 2009 Matteo Cantiello Long GRB Progenitors Sedgwick 2011 Matteo Cantiello Long GRB Progenitors CfA 2012 Matteo Cantiello Long GRB Progenitors UCSB 2012 Matteo Cantiello MESA School
16. Calibrating Rotational Mixing
17. Calibration § Asteroseismology § Surface Abundances § ... NS & GRBs 2009 (ﺓةﻱيﺭرﺩدﻥنﻙكﺱسﺇإﻝلﺍا - Alexandria) Matteo Cantiello Long GRB Progenitors Fireworks 2009 (Bonn) Matteo Cantiello Long GRB Progenitors Leicester 2009 Matteo Cantiello Long GRB Progenitors Stockholm 2009 Matteo Cantiello Long GRB Progenitors Sedgwick 2011 Matteo Cantiello Long GRB Progenitors CfA 2012 Matteo Cantiello Long GRB Progenitors UCSB 2012 Matteo Cantiello MESA School
18. Asteroseismology NS & GRBs 2009 (ﺓةﻱيﺭرﺩدﻥنﻙكﺱسﺇإﻝلﺍا - Alexandria) Matteo Cantiello Long GRB Progenitors Fireworks 2009 (Bonn) Matteo Cantiello Long GRB Progenitors Leicester 2009 Matteo Cantiello Long GRB Progenitors Stockholm 2009 Matteo Cantiello Long GRB Progenitors Sedgwick 2011 Matteo Cantiello Long GRB Progenitors CfA 2012 Matteo Cantiello Long GRB Progenitors UCSB 2012 Matteo Cantiello MESA School Rotation lifts the degeneracy in the azimuthal order m of non-radial oscillation modes. This results in (2l + 1) frequency peaks in the power spectrum for each mode. The frequency spacings between these peaks are called rotational splittings and are directly related to the angular velocity and the properties of the modes in their propagation regions inside the star. Eggenberger et al .2012
19. NS & GRBs 2009 (ﺓةﻱيﺭرﺩدﻥنﻙكﺱسﺇإﻝلﺍا - Alexandria) Matteo Cantiello Long GRB Progenitors Fireworks 2009 (Bonn) Matteo Cantiello Long GRB Progenitors Leicester 2009 Matteo Cantiello Long GRB Progenitors Stockholm 2009 Matteo Cantiello Long GRB Progenitors Sedgwick 2011 Matteo Cantiello Long GRB Progenitors CfA 2012 Matteo Cantiello Long GRB Progenitors UCSB 2012 Matteo Cantiello MESA School Rotation & Asteroseismology
20. NS & GRBs 2009 (ﺓةﻱيﺭرﺩدﻥنﻙكﺱسﺇإﻝلﺍا - Alexandria) Matteo Cantiello Long GRB Progenitors Fireworks 2009 (Bonn) Matteo Cantiello Long GRB Progenitors Leicester 2009 Matteo Cantiello Long GRB Progenitors Stockholm 2009 Matteo Cantiello Long GRB Progenitors Sedgwick 2011 Matteo Cantiello Long GRB Progenitors CfA 2012 Matteo Cantiello Long GRB Progenitors UCSB 2012 Matteo Cantiello MESA School Asteroseismology
21. Surface Abundances NS & GRBs 2009 (ﺓةﻱيﺭرﺩدﻥنﻙكﺱسﺇإﻝلﺍا - Alexandria) Matteo Cantiello Long GRB Progenitors Fireworks 2009 (Bonn) Matteo Cantiello Long GRB Progenitors Leicester 2009 Matteo Cantiello Long GRB Progenitors Stockholm 2009 Matteo Cantiello Long GRB Progenitors Sedgwick 2011 Matteo Cantiello Long GRB Progenitors CfA 2012 Matteo Cantiello Long GRB Progenitors UCSB 2012 Matteo Cantiello MESA School Brott et al. 2011
22. Calibration: Hunter Diagram NS & GRBs 2009 (ﺓةﻱيﺭرﺩدﻥنﻙكﺱسﺇإﻝلﺍا - Alexandria) Matteo Cantiello Long GRB Progenitors Fireworks 2009 (Bonn) Matteo Cantiello Long GRB Progenitors Leicester 2009 Matteo Cantiello Long GRB Progenitors Stockholm 2009 Matteo Cantiello Long GRB Progenitors Sedgwick 2011 Matteo Cantiello Long GRB Progenitors CfA 2012 Matteo Cantiello Long GRB Progenitors UCSB 2012 Matteo Cantiello MESA School Brott et al. 2011
23. Calibration
24. NS & GRBs 2009 (ﺓةﻱيﺭرﺩدﻥنﻙكﺱسﺇإﻝلﺍا - Alexandria) Matteo Cantiello Long GRB Progenitors Fireworks 2009 (Bonn) Matteo Cantiello Long GRB Progenitors Leicester 2009 Matteo Cantiello Long GRB Progenitors Stockholm 2009 Matteo Cantiello Long GRB Progenitors Sedgwick 2011 Matteo Cantiello Long GRB Progenitors CfA 2012 Matteo Cantiello Long GRB Progenitors UCSB 2012 Matteo Cantiello MESA School Calibration: Hunter Diagram Brott et al. 2011
25. NS & GRBs 2009 (ﺓةﻱيﺭرﺩدﻥنﻙكﺱسﺇإﻝلﺍا - Alexandria) Matteo Cantiello Long GRB Progenitors Fireworks 2009 (Bonn) Matteo Cantiello Long GRB Progenitors Leicester 2009 Matteo Cantiello Long GRB Progenitors Stockholm 2009 Matteo Cantiello Long GRB Progenitors Sedgwick 2011 Matteo Cantiello Long GRB Progenitors CfA 2012 Matteo Cantiello Long GRB Progenitors UCSB 2012 Matteo Cantiello MESA School Calibration: Hunter Diagram Brott et al. 2011
26. NS & GRBs 2009 (ﺓةﻱيﺭرﺩدﻥنﻙكﺱسﺇإﻝلﺍا - Alexandria) Matteo Cantiello Long GRB Progenitors Fireworks 2009 (Bonn) Matteo Cantiello Long GRB Progenitors Leicester 2009 Matteo Cantiello Long GRB Progenitors Stockholm 2009 Matteo Cantiello Long GRB Progenitors Sedgwick 2011 Matteo Cantiello Long GRB Progenitors CfA 2012 Matteo Cantiello Long GRB Progenitors UCSB 2012 Matteo Cantiello MESA School Calibration: Hunter Diagram Brott et al. 2011
27. Magnetic Braking
28. Fossil Fields and Magnetic Braking § Magnetic fields can increase wind angular momentum loss (Weber & Davis 1967, ud-Doula & Owocki 2002) § Spin-down time measured in Sigma Ori matches theoretical predictions (Townsend et al. 2010) § Potentially important for stellar evolution models (e.g. Meynet et al. 2011) Tau Sco, Jardin & Donati UCSB 2012 Matteo Cantiello MESA School
29. Fossil Fields and Magnetic Braking § Magnetic fields can increase wind angular momentum loss (Weber & Davis 1967, ud-Doula & Owocki 2002) § Spin-down time measured in Sigma Ori matches theoretical predictions (Townsend et al. 2010) § Potentially important for stellar evolution models (e.g. Meynet et al. 2011) § Magnetic Braking could be implemented in MESA... Tau Sco, Jardin & Donati UCSB 2012 Matteo Cantiello MESA School
30. Wind Confinement Parameter (ud-Doula & Owocki 2002) For a magnetic monopole For an aligned dipole UCSB 2012 Matteo Cantiello MESA School Fossil Fields and Magnetic Braking
31. § Magnetic fields can increase wind angular momentum loss (Weber & Davis 1967, ud-Doula & Owocki 2002) Wind Confinement Parameter (ud-Doula & Owocki 2002) For a magnetic monopole For an aligned dipole UCSB 2012 Matteo Cantiello MESA School Fossil Fields and Magnetic Braking
32. § Magnetic fields can increase wind angular momentum loss (Weber & Davis 1967, ud-Doula & Owocki 2002) Wind Confinement Parameter (ud-Doula & Owocki 2002) For a magnetic monopole For an aligned dipole UCSB 2012 Matteo Cantiello MESA School Fossil Fields and Magnetic Braking
33. UCSB 2012 Matteo Cantiello MESA School Fossil Fields and Magnetic Braking § Where to extract J? § Down in the star, until you run out of it § Uniformly through out the star § Just at the surface § ... §Remember to account for the fact that MESA already removed same J through a non-magnetic wind
34. Calibration NS & GRBs 2009 (ﺓةﻱيﺭرﺩدﻥنﻙكﺱسﺇإﻝلﺍا - Alexandria) Matteo Cantiello Long GRB Progenitors Fireworks 2009 (Bonn) Matteo Cantiello Long GRB Progenitors Leicester 2009 Matteo Cantiello Long GRB Progenitors Stockholm 2009 Matteo Cantiello Long GRB Progenitors Sedgwick 2011 Matteo Cantiello Long GRB Progenitors CfA 2012 Matteo Cantiello Long GRB Progenitors UCSB 2012 Matteo Cantiello MESA School
35. UCSB 2012 Matteo Cantiello MESA School Fossil Fields and Magnetic Braking
36. UCSB 2012 Matteo Cantiello MESA School Fossil Fields and Magnetic Braking
37. § Magnetic fields can increase wind angular momentum loss (Weber & Davis 1967, ud-Doula & Owocki 2002) § Spin-down time measured in Sigma Ori matches theoretical predictions (Townsend et al. 2010) § Potentially important for stellar evolution models (e.g. Meynet et al. 2011) § Magnetic Braking could be implemented in MESA Mini=10MSun, Vini=200 km/s (Meynet et al. 2011) UCSB 2012 Matteo Cantiello MESA School Fossil Fields and Magnetic Braking
38. UCSB 2012 Matteo Cantiello MESA School Fossil Fields and Magnetic Braking N
39. Mini Lab UCSB 2012 Matteo Cantiello MESA School
40. Mini Lab
41. Mini Lab ASSIGNMENT 2
42. /mesa/star /work Run_star ../data /private MESA Star /public Inlist prole_columns log_columns run_star_extra.f sub other_* extra_jdot