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Radiation-SPH Simulations on the Radiative Feedback of POPIII Stars

Radiation-SPH Simulations on the Radiative Feedback of POPIII Stars. Hajime Susa (Rikkyo,JPN) Collaborator: Masayuki Umemura (Tsukuba). Radiative Feedback. Processes photoionization photoevaporation enhance H2 formation H2 dissociation by Lyman-Werner (LW) Band photons H2 destruction

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Radiation-SPH Simulations on the Radiative Feedback of POPIII Stars

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  1. Radiation-SPH Simulations on the Radiative Feedback of POPIII Stars Hajime Susa (Rikkyo,JPN) Collaborator: Masayuki Umemura (Tsukuba) EANAM2006(大田)

  2. Radiative Feedback • Processes • photoionization • photoevaporation • enhance H2 formation • H2 dissociation by Lyman-Werner (LW) Band photons • H2 destruction • H2+, H- destruction • Outcome • self-regulation of SF in the early universe • Source of reionization Abel et al. 2006 EANAM2006(大田)

  3. Three phases of Radiative feedbackfrom dark to luminous ages • Phase I: local feedback from single POPIII（ionization+dissociation） e.g. Omukai & Nishi 1999; Glover & Brand 2001;Susa & Umemura 2006; Ahn & Shapiro 2006; Yoshida et al.(2006) • Phase II: diffuse LW background (built up by many stars) e.g. Haiman et al. 1997; Ciardi et al. 2000; Oh & Haiman 2003 ; Mesinger ,Bryan, Haiman 2006 • PhaseIII: diffuse ionizing photon background →Reionization of the univ. e.g. Barkana & Loeb 2000; Kitayama et al. 2000,2001; Susa & Umemrua 2004ab EANAM2006(大田)

  4. Local H2 photodissociation feedback in uniform gas cloud Uniform low mass host clouds are totally Photodissociated by single POPIII star. Omukai & Nishi 1999 EANAM2006(大田)

  5. H2 photodissociation feedback on clumpy cloud Glover & Brand 2001 Dense clouds are able to survive the photodissociation feedback by another nearby star. • Dynamically collapsing cloud ? • Photoionization? Radiation hydrodynamics simulations EANAM2006(大田)

  6. Numerical Methods H. Susa, PASJ 58, 445 (2006) • Tree • SPH • RT of Ionizing photons by Ray Tracing • RT of Lyman-Werner photons by Ray Tracing ( Self-Shielding function) • Implicit solver for reactions and energy equation • H2 (no He) • Everything parallelized utilizing MPI EANAM2006(大田)

  7. FIRST 240 nodes 480 CPU ＋ 240 Blade-GRAPE 480 Xeon : 2.9 Tflops Blade-GRAPE:8.7 Tflops Memory:512GB Now available EANAM2006(大田)

  8. Uniform dense clump Run-away collapsing Core Turn on the nearby star Setup SPH particles Uniformly Distributed EANAM2006(大田)

  9. Parameters Property of the Source Star c.f. size of the first star forming halos are several ×10pc EANAM2006(大田)

  10. LW feedback (without ionization) Susa 2006 in prep. EANAM2006(大田)

  11. Failed Collapse ( H2 fraction ) LW photons sweep the dense core and prevent the cloud from collapsing. Core bounce EANAM2006(大田)

  12. Survived prestellar core (H2 fraction) H2 is self-shielded Collapsed core EANAM2006(大田)

  13. Time evolution of Central density collapse bounce Turn-on EANAM2006(大田)

  14. H2 reformation Evolution of central density & tempetarute Three different initial Tof collapsing cloud collapse Bounce EANAM2006(大田)

  15. Analytic cooling condition Once the collapsing core satisfy above condition, the collapse cannot be stopped. EANAM2006(大田)

  16. D=20pc RUN AWAY REGION Bounce collapse Susa, in preparation (2006) EANAM2006(大田)

  17. Comparison with the condition tdis > tff ( Glover & Brand 2001) Importance of dynamical effect (H2 recovery) EANAM2006(大田)

  18. LW + Ionizing photons Susa & Umemura (2006) Susa & Umumura in prep. EANAM2006(大田)

  19. Photoevaporation (less dense core) • All of the gas is • photoevaorated and • the dense clump disappers • The I-front propagates as • R-type. EANAM2006(大田)

  20. Self-shielding condition for Static Core EANAM2006(大田)

  21. Disrupted Core by shock M-type IF induce shock, that destroy the core. EANAM2006(大田)

  22. H2 shell formation&Enhancement of H2 in the core Bounce EANAM2006(大田)

  23. Competition of various effects • H2 dissociation • Photoevaporation (thermal pressure / shock) • Self-shielding (LW / ionizing photons) • Enhanced H2 formation in the core (→Ahn) • H2 shell formation EANAM2006(大田)

  24. Summary of Runs (non-D plane) LW only LW + ION Effects of photoionization alleviates the negative feedback of photodissociation EANAM2006(大田)

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