Simona Gallerani

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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. - PowerPoint PPT Presentation

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

  • Pre-overlap stageOverlap stagePost-overlap stageReionization: a phase transition in the early Universe Dark ages~500 kyr~100 Myr1 Gyrz~1000z~6z~20

  • Reionization process: observational constraints Komatsu et al. (2009)

  • Becker et al. (2003)QSOs constraints on cosmic reionizationSDSS~20 QSOs@ 5.7
  • GRBs constraints on cosmic reionization GRB 050904 @ z = 6.3SUBARU TELESCOPE(Totani et al. 2005) (Tagliaferri et al. 2005)

  • (Kashikawa et al. 2006) SUBARU DEEP FIELDLAEs @ z=6.6LAEs constraints on cosmic reionizationLAEs @ z=5.7VS

  • Modeling reionizationChoudhury & Ferrara (2005/2006); Choudhury, Ferrara & SG (2008) Free parameters:

  • Reionization modelsPhoto-Ionization Rate Data from McDonald & Miralda-Escude(2001); Bolton et al. (2007); Fan et al.(2006)

  • Simulating the Ly forest Optical depth(Voigt profile)SG, Choudhury & Ferrara (2006)

  • Simulated spectraOptical depth evolutionSG, Choudhury & Ferrara (2006)

  • Largest gap width distributionObservations vs Simulations xHI
  • GRBs absorption spectraKawai et al. (2006) 52 GRB050904 @ z=6.3 Tagliaferri et al. (2005)

  • 142 GRBs absorption spectraKawai et al. (2006)GRB050904 @ z=6.3 Tagliaferri et al. (2005)

  • 190 GRBs absorption spectraKawai et al. (2006)GRB050904 @ z=6.3 Tagliaferri et al. (2005)

  • Largest gap probability isocontours: GRBs SG, Salvaterra, Ferrara, Choudhury (2007)The ERM is twice more probable wrt the LRMThe gap sizes are consistent with xHI=6.410-3.5%5%10%10%40%40%

  • LAEs constraints on cosmic reionizationDayal, Ferrara, SG (2008)

    zf*/DCfesc,4.53.50.0755.73.50.36.63.50.3

    zMh (Msun)SFR(Msun/yr)4.51011.1-12.56-1605.71010.8-12.33-1036.61010.7-12.02-43

  • 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 Ly luminosity function @ 5.7=7, in agreement with WMAP5 data.

  • Largest gap width distributionObservations vs Simulations Low Redshift (zem6)

    LRMERM

  • Ly emitting galaxies

    fesc fraction of ionizing photons that escape the galaxyf fraction of Ly photons that escape the galaxyQ ionizing photons ratef* fraction of baryonic matter which forms stars over a timescale t*=DCtHfesc=0.1; SFR=113 Msun/yr; t*=1.e8 yr