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Constraining Reionization through Quasar and Gamma Ray Burst Absorption Spectra

Explore constraints on cosmic reionization using quasar and gamma-ray burst absorption spectra data, discussing early and late reionization models, transverse proximity effect, and peak spectral density.

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Constraining Reionization through Quasar and Gamma Ray Burst Absorption Spectra

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  1. Constraining reionization through quasar and gamma ray burst absorption spectra Simona Gallerani Astronomical Observatory of Rome In collaboration with: T. Roy Choudhury, P. Dayal, X. Fan, A. Ferrara, A. Maselli, R. Salvaterra COSMOLOGICAL REIONIZATION CONFERENCE Harish-Chandra Research Institute, Allahabad, 16 February 2010

  2. DAVID The Dark Ages VIrtual Department http://wiki.arcetri.astro.it/bin/view/DAVID/WebHome S. Bianchi INAF/Arcetri B. Ciardi MPA P. Dayal SISSA C. Evoli SISSA A. Ferrara SNS Pisa S. Gallerani INAF/Roma F. Iocco IAP F. Kitaura SNS Pisa • Maselli • INAF/Arcetri R. Salvaterra INAF/Milano S. Salvadori KAI Groningen R. Schneider INAF/Arcetri R. Valiante Univ. Firenze M. Valdes IPMU

  3. Fan et al. (2005) QSOs constraints on cosmic reionization SDSS +CFHQS ~40 QSOs Becker et al. (2003) @ 5.7<z<6.4 in contrast with WMAP Komatsu et al. (2009 / 2010)

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

  5. ERM LRM Reionizationmodels EARLY REIONIZATION (ERM) LATE REIONIZATION (LRM) Highly ionizedIGM at z=6 Two-phaseIGM at z >6 Volume Filling Factor Photo- Ionization Rate Data from McDonald & Miralda-Escude’(2001); Bolton etal. (2005/2007); Fan etal.(2006)

  6. ERM LRM Statistics of the transmitted flux Fan et al. (2006) Songaila (2004) Data from Fan etal. (2002); Songaila (2004); Fan etal.(2006)

  7. ERM LRM GAPS Gaps in the Lyα forest Largest gap width distribution SG, Choudhury, Ferrara (2006)

  8. ERM LRM Largest gap width distribution Comparison with 20 QSOs at 5.7 < z < 6.4 (Fan et al. 2006) SG, Ferrara, Fan, Choudhury 2008

  9. ERM LRM Largest gap width distribution Comparison with 20 QSOs at 5.7 < z < 6.4 (Fan et al. 2006) LR @ SG, Ferrara, Fan, Choudhury (2008)

  10. Transverse proximity effect background QSO foreground QSO Proximity effect along the line of sight Gunn-Peterson through Transverse proximity effect

  11. First-ever detection of the Transverse Proximity Effect in the HI Lyα forest RD J1148+5252 Mpc QSO1 Mahabal et al. (2005) Fan et al. (2006) QSO2 TPE Peak Spectral Density See also Worseck et al. 2007 SG, Ferrara, Fan, Choudhury (2008)

  12. Observed absorption spectrum of GRB050904 @ z=6.3 Kawai et al. (2006) 52 Å

  13. Observed absorption spectrum of GRB050904 @ z=6.3 Kawai et al. (2006) 142 Å

  14. Observed absorption spectrum of GRB050904 @ z=6.3 Kawai et al. (2006) 190 Å DLA Totani et al. (2006)

  15. Largest gap probability isocontours: GRBs 5% 40% 5% 10% SG, Salvaterra, Ferrara, Choudhury (2008) 10% 40% The ERM is 10 times more probable wrt the LRM The gap sizes are consistent with xHI~10-4. In agreement with Totani et al. (2006)

  16. Current observational data of QSO absorption spectra do not require any sudden change in the IGM ionization state @ z~6, instead favour a highly ionized IGM at these epochs.   First-ever detection of the transverse proximity effect in the HI Lyα forest along the line of sight towards the highest–z QSO known. Conclusions: An Early Reionization Model  Further applications of the Early Reionization Model: Quasar HII regions  see Maselli’s talk (in the afternoon) Lyα emitters luminosity function see Dayal’s talk (tomorrow) The analysis of the GRB050904 at z=6.3 confirms the results found in QSO studies. In particular, the gap size along the observed line of sight is consistent with xHI ~10-4.  The overall result points towards an extended reionization process which starts at z>=11 and completes at z>=7, in agreement with WMAP data.

  17. Transverse proximity effect: observations vs simulations Peak Spectral Density

  18. PEAKS  Transverse proximity effect in the LOS towards the highest –z QSO.  Observed peaks are much larger than simulated ones  Lower limit on the foreground QSO lifetime Conclusions

  19. Log-Normal model: observational confirmation

  20. Log-Normal model: observational confirmation (Becker et al. 2006) Miralda-Escude’ et al (2000)

  21. Log-Normal model vs MHR00 at z=6 Miralda-Escude’ et al (2000)

  22. Log-Normal model vs MHR00 Miralda-Escude’ et al (2000)

  23. Gap width distribution SG, Choudhury, Ferrara (2006)

  24. LARGEST Gap width distribution SG, Choudhury, Ferrara (2006)

  25. Gap width distribution: LogNormal vs HYDROPM simulations SG, Choudhury, Ferrara (2006)

  26. redshift redshift Modelling a late reionization scenario LRM random distribution of neutral regions LRMc clustering of neutral pixels

  27. Largest dark gap distribution Gallerani S., Choudhury T., Ferrara A. (2006)

  28. Ionizing sources Left over by reionization Should the distribution of neutral regions depend on the clustering of ionizing sources? 2D Maps of neutral hydrogen distribution (Ciardi, Ferrara & White 2003) Clustering of ionizing sources might not be correlated significantly with neutral regions in the case of a very high filling factor.

  29. MASS OF DM HALOS HOSTING THE IONIZING SOURCES PEAK FREQUENCY & SIZE Transmissivity windows from HII regions

  30. Mo & White (2002) Hints on the mass of DM halos hosting high-z QSOs Frequency Size Discrepancy It is unlikely that QSOs HII regions produce peaks consistent with data, unless they reside in highly overdense regions.

  31. Observations High Redshift (HR) Low Redshift (LR) Fan et al. (2006)

  32. Simulated spectra Observed spectra GAP GAP Dark gaps statistics Dark gaps: “contiguous regions of the spectrum with  > 2.5 over rest frame wavelength intervals greater then 1Å”. Data from Songaila & Cowie (2002)

  33. QSO1 QSO2 Mpc Transverse proximity effect: observations RD J1148+5252 Mahabal et al. (2005) Fan et al. (2006)

  34. QSO1 QSO2 Mpc Transverse proximity effect: observations RD J1148+5252 Mahabal et al. (2005) Fan et al. (2006) White et al. (2003) Wyithe et al. (2005) Yu (2005) Shapiro et al. (2006)

  35. Peaks origin: Underdense Regions (case A) Peak Spectral Density Transverse proximity effect: simulations HII Regions (case B) SG, Ferrara, Fan, Choudhury (2007)

  36. Transverse proximity effect: observations vs simulations

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