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Simona Gallerani

Constraining cosmic reionization models with QSOs, GRBs and LAEs observational data. Simona Gallerani. Astronomical Observatory of Rome. In collaboration with: A. Ferrara, X. Fan, T. Choudhury, R. Salvaterra , P. Dayal.

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Simona Gallerani

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  1. Constraining cosmic reionization models with QSOs, GRBs and LAEs observational data Simona Gallerani Astronomical Observatoryof Rome In collaboration with: A. Ferrara, X. Fan,T. Choudhury, R. Salvaterra, P. Dayal

  2. What is the epochof reionization (EOR)? Reionization: a phase transition in the early Universe ~500 kyr ~100 Myr ≤1 Gyr Dark ages z~1000 z~20 z~6 Overlap stage Post-overlap stage Pre-overlap stage

  3. CMB Page et al. (2007) Quasars Ly Emitters Gamma Ray Bursts Reionization process: observational constraints Komatsu et al. (2009)

  4. Fan et al. (2005) QSOs constraints on cosmic reionization SDSS ~20 QSOs @ 5.7<z<6.4 Becker et al. (2003)

  5. { DLA system Transmission feature around the Ly line MODELLING Neutral IGM GRBs constraints on cosmic reionization SUBARU TELESCOPE GRB 050904 @ z = 6.3 (Tagliaferri et al. 2005)  (Totani et al. 2005)

  6. No evolution LFLyα for 3<z<6 No evolution LFUV for 5.7<z<6.6 LAEs constraints on cosmic reionization SUBARU DEEP FIELD LAEs @ z=6.6 VS LAEs @ z=5.7 (Kashikawa et al. 2006)

  7. Log-Normal model QSOs, PopII, PopIII Modeling reionization Free parameters: Choudhury & Ferrara (2005/2006); Choudhury, Ferrara & SG (2008)

  8. ERM LRM Early Reionization (ERM) Highly ionized IGM at z=6 Late Reionization (LRM) Two-phase IGM at z>6 Reionization models Photo-Ionization Rate Data from McDonald & Miralda-Escude’(2001); Bolton et al. (2007); Fan et al.(2006)

  9. Density field Log-Normal model (ΛCDM) Coles & Jones (1991) Neutral hydrogen Reionization model (TIGM; UVB) Choudhury & Ferrara (2006) Simulating the Ly forest Optical depth (Voigt profile) SG, Choudhury & Ferrara (2006)

  10. ERM LRM Fan et al. (2006) Songaila (2004) GAPS Simulated spectra Optical depth evolution SG, Choudhury & Ferrara (2006)

  11. ERM ERM LRM LRM Largest gap width distribution Observations vs Simulations Low Redshift (zem<6) High Redshift (zem>6) SG, Ferrara, Fan, Choudhury (2007) xHI<0.36 @ z=6.3

  12. GRBs absorption spectra 52 Å GRB050904 @ z=6.3 Kawai et al. (2006) Tagliaferri et al. (2005)

  13. GRBs absorption spectra 142 Å GRB050904 @ z=6.3 Kawai et al. (2006) Tagliaferri et al. (2005)

  14. GRBs absorption spectra 190 Å GRB050904 @ z=6.3 Kawai et al. (2006) Tagliaferri et al. (2005)

  15. Largest gap probability isocontours: GRBs 5% 5% 10% 10% SG, Salvaterra, Ferrara, Choudhury (2007) 40% 40% The ERM is twice more probable wrt the LRM The gap sizes are consistent with xHI=6.410-3.

  16. Shimazaku et al 06 -2.5 Kashikawa et al 06 14 Dawson et al 07 xHI=1e-3 xHI=0.05 xHI=0.1 12 -3.5 10 Log N (>Lα) [Mpc-3] 8 -4.5 Lα[1042erg/sec] fesc=0.1; SFR=113 Msun/yr; t*=1.e8 yr 6 4 -5.5 2 42 42.5 43 43.5 0 Log Lα[erg/sec] 9040 9120 9180 obs LAEs constraints on cosmic reionization Dayal, Ferrara, SG (2008)

  17. An Early Reionization Model (ERM) • The analysis of dark regions (gaps) in QSO absorption spectra favors a highly ionized IGM @ z~6. • The gap size along the LOS towards the GRB050904 @ z=6.3 • is consistent with xHI ~10-3. • The evolution of the Lyα luminosity function @ 5.7<z<6.6 • is well fitted by a reionization model with zrei ≥ 7. The overall result points towards an extended reionization process which starts atz>=11 and completes atz>=7, in agreement with WMAP5 data.

  18. HR Fan et al. (2006 This work Largest gap width distribution Observations vs Simulations Low Redshift (zem<6) High Redshift (zem>6) SG, Ferrara, Fan, Choudhury (2007) ERM LRM LRM ERM

  19. 14 xHI=1e-3 xHI=0.05 xHI=0.1 12 10 8 Lα[1042erg/sec] 6 4 2 0 9040 9120 9180 obs Lyα emitting galaxies fesc fraction of ionizing photons that escape the galaxy fαfraction of Lyα photons that escape the galaxy fesc=0.1; SFR=113 Msun/yr; t*=1.e8 yr Q ionizing photons rate f* fraction of baryonic matter which forms stars over a timescale t*=εDCtH

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