Constraining reionization
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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

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Simona gallerani

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


Simona gallerani

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


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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)


Simona gallerani

Log-Normal model

QSOs, PopII, PopIII

Free parameters:

Modeling reionization

Choudhury

&

Ferrara

(2005/2006)


Simona gallerani

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)


Simona gallerani

ERM

LRM

Statistics of the transmitted flux

Fan et al. (2006)

Songaila (2004)

Data from Fan etal. (2002); Songaila (2004); Fan etal.(2006)


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ERM

LRM

GAPS

Gaps in the Lyα forest

Largest gap width distribution

SG, Choudhury, Ferrara (2006)


Simona gallerani

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


Simona gallerani

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)


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Transverse proximity effect

background QSO

foreground QSO

Proximity effect

along the line of sight

Gunn-Peterson

through

Transverse

proximity effect


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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)


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Observed absorption spectrum of GRB050904 @ z=6.3

Kawai et al. (2006)

52 Å


Simona gallerani

Observed absorption spectrum of GRB050904 @ z=6.3

Kawai et al. (2006)

142 Å


Simona gallerani

Observed absorption spectrum of GRB050904 @ z=6.3

Kawai et al. (2006)

190 Å

DLA

Totani et al. (2006)


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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)


Simona gallerani

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.


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Transverse proximity effect: observations vs simulations

Peak Spectral Density


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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


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Log-Normal model: observational confirmation


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Log-Normal model: observational confirmation

(Becker et al. 2006)

Miralda-Escude’ et al (2000)


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Log-Normal model vs MHR00 at z=6

Miralda-Escude’ et al (2000)


Simona gallerani

Log-Normal model vs MHR00

Miralda-Escude’ et al (2000)


Simona gallerani

Gap width distribution

SG, Choudhury, Ferrara (2006)


Simona gallerani

LARGEST Gap width distribution

SG, Choudhury, Ferrara (2006)


Simona gallerani

Gap width distribution:

LogNormal vs HYDROPM simulations

SG, Choudhury, Ferrara (2006)


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redshift

redshift

Modelling a late reionization scenario

LRM

random distribution

of neutral regions

LRMc

clustering

of neutral pixels


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Largest dark gap distribution

Gallerani S., Choudhury T., Ferrara A. (2006)


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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.


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MASS OF DM HALOS

HOSTING

THE IONIZING SOURCES

PEAK

FREQUENCY & SIZE

Transmissivity windows from HII regions


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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.


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Observations

High Redshift (HR)

Low Redshift (LR)

Fan et al. (2006)


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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)


Simona gallerani

QSO1

QSO2

Mpc

Transverse proximity effect: observations

RD J1148+5252

Mahabal et al. (2005)

Fan et al. (2006)


Simona gallerani

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)


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Peaks origin:

Underdense

Regions

(case A)

Peak Spectral Density

Transverse proximity effect: simulations

HII

Regions

(case B)

SG, Ferrara, Fan, Choudhury (2007)


Simona gallerani

Transverse proximity effect: observations vs simulations


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