Simona Gallerani

Constraining reionization through quasar and gamma ray burst absorption spectra

In collaboration with:

T. Roy Choudhury, P. Dayal, X. Fan, A. Ferrara, A. Maselli, R. Salvaterra

COSMOLOGICAL REIONIZATION CONFERENCEHarish-Chandra Research Institute, Allahabad, 16 February 2010

Astronomical Observatory of Rome

DAVID The Dark Ages VIrtual Departmenthttp://wiki.arcetri.astro.it/bin/view/DAVID/WebHome

S. BianchiINAF/Arcetri

B. CiardiMPA

P. DayalSISSA

C. EvoliSISSA

A. FerraraSNS Pisa

S. GalleraniINAF/Roma

F. IoccoIAP

F. KitauraSNS Pisa

A. MaselliINAF/Arcetri

R. SalvaterraINAF/Milano

S. SalvadoriKAI Groningen

R. SchneiderINAF/Arcetri

M. ValdesIPMU

R. ValianteUniv. Firenze

QSOs constraints on cosmic reionization

SDSS +CFHQS

~40 QSOs

@ 5.7<z<6.4

€

zrei ~ 6Fan et al. (2005)

€

zrei ~ 11in contrast with WMAP

Komatsu et al. (2009 / 2010)

Becker et al. (2003)

Modeling reionization

Choudhury &

Ferrara (2005/2006)

Free parameters:SFPopIII

SFPopII ,

escPopIII

escPopII ff ,

Log-Normal model QSOs, PopII, PopIII

Reionization models

EARLY REIONIZATION (ERM) LATE REIONIZATION (LRM)

6reionz 6reionz

VolumeFillingFactor

Photo-Ionization

Rate

ERM

LRM

Data from McDonald & Miralda-Escude’(2001); Bolton etal. (2005/2007); Fan etal.(2006)

Highly ionized IGM at z=6 Two-phase IGM at z >6€

PopIISF = 0.08

fPopIIesc = 0.04

€

PopIISF = 0.1

fPopIIesc = 0.07

Statistics of the transmitted flux

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

ERM

LRM

Fan et al. (2006)

Songaila (2004)

Gaps in the Lyα forest3.67.5 zERM

LRM

GAPSGAPS

SG, Choudhury, Ferrara (2006)

Largest gap width distribution

€

z > 6

Largest gap width distribution

Comparison with 20 QSOs at 5.7 < z < 6.4 (Fan et al. 2006)

ERM

LRM

SG, Ferrara, Fan, Choudhury 2008

€

z < 6

Largest gap width distributionERM

LRM

5104 HIx3.5z

LR

SG, Ferrara, Fan, Choudhury (2008)

@ 3.6z36.0HIx

€

z > 6

Comparison with 20 QSOs at 5.7 < z < 6.4 (Fan et al. 2006)

Transverse proximity effect

Proximity effectalong the line of sight

Transverse proximity effect

Gunn-Peterson through

foreground QSO

background QSO

First-ever detection of the Transverse Proximity Effect in the HI Lyα forestM

ahab

al e

t al.

(200

5)

Fan et al. (2006)

QSO1

QSO2

RD J1148+5252

7.0R

3.24BM

Mpc

OUTIN PSDPSD 4

€

=dN peaks

dλPeak Spectral Density

See also Worseck et al. 2007

TPE

SG, Ferrara, Fan, Choudhury (2008)

€

zem = 5.7

Observed absorption spectrum of GRB050904 @ z=6.3K

awai et al. (2006)

52 Å

Observed absorption spectrum of GRB050904 @ z=6.3K

awai et al. (2006)

142 Å

Observed absorption spectrum of GRB050904 @ z=6.3K

awai et al. (2006)190 Å

DLA Totani et al. (2006)

Largest gap probability isocontours: GRBs SG

, Sal

vate

rra,

Fer

rara

, Cho

udhu

ry (

2008

)

The ERM is 10 times more probable wrt the LRM

The gap sizes are consistent with xHI~10-4.

5%10%

40%

5%

10%

40%

In agreement with Totani et al. (2006)

Conclusions: An Early Reionization Model

First-ever detection of the transverse proximity effect in the HI Lyα forest along the line of sight towards the highest–z QSO known.

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 sightis consistent with xHI ~10-4.

Current observational data of QSO absorption spectrado not require any sudden change in the IGM ionization state @ z~6, instead favour a highly ionized IGM at these epochs.

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 overall result points towards an extended reionization process which starts at z>=11 and completes at z>=7,

in agreement with WMAP data.

Transverse proximity effect: observations vs simulations

€

tQ >Rτ − R⊥

c≈11Myr

OUTIN PSDPSD 4€

=dN peaks

dλPeak Spectral Density

PEAKSPEAKS

Conclusions

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 MyrtQ 18

Log-Normal model: observational confirmation

2

2

2

)(lnexp

2

1)(

P

2'

2'

' 2

)(lnexp

2

1)(

P

€

∝2

Aln;2

''

Log-Normal model: observational confirmation

(Becker et al. 2006)

Miralda-Escude’ et al (2000)

Log-Normal model vs MHR00 at z=6

Miralda-Escude’ et al (2000)

Log-Normal model vs MHR00

Miralda-Escude’ et al (2000)

Gap width distribution

SG, Choudhury, Ferrara (2006)

LARGEST Gap width distribution

SG, Choudhury, Ferrara (2006)

Gap width distribution: LogNormal vs HYDROPM simulations

SG, Choudhury, Ferrara (2006)

Modelling a late reionization scenario

LRMrandom distribution

of neutral regions

LRMcclustering

of neutral pixels

redshift redshift

Largest dark gap distribution

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

2D Maps of neutral hydrogen distribution (Ciardi, Ferrara & White 2003)

Should the distribution of neutral regions depend on the clustering of ionizing sources?

Clustering of ionizing sources might not be correlated significantly with neutral regions in the case of a very high filling factor.

Ionizingsources

Left over by reionization

Transmissivity windows from HII regions

PEAKFREQUENCY & SIZE

MASS OF DM HALOS HOSTING

THE IONIZING SOURCES

Size

Frequency

Hints on the mass of DM halos hosting high-z QSOs

3/1

4

3

HHI

QHII nx

tNR

Discrepancy It is unlikely that QSOs HII regions produce peaks consistent with data, unless they reside in highly overdense regions.

MMh810

yrtQ710

5105 HIx

Mo & White (2002)

MMh1312 1010

5.5z

LOShhHII LMnR )(2

Observations

5.99 J1306-0356

5.95

5.93

J1335+3533

J1411+1217

5.85 J0005-0006

5.82 J0836+0054

5.80

5.79

5.74

J0002-2550

J0927+2001

J1044-0125

emz QSO

6.42 J1148+5251

6.28 J1030+0524

6.25 J1623+3112

6.20 J1048+4637

6.13

6.07

J1250+3130

J1602+4228

6.01

6.00

J1137+3549

J0818+1722

emz QSO

Fan et al. (2006)

Low Redshift (LR) High Redshift (HR)

Dark gaps statistics

Dark gapsDark gaps: “contiguous regions of the : “contiguous regions of the spectrum with spectrum with > 2.5 over rest frame > 2.5 over rest frame wavelength intervals greater then 1wavelength intervals greater then 1Å”.Å”.

Data from Songaila & Cowie (2002)

Simulated spectra Observed spectra

GAP

GAP

Transverse proximity effect: observationsM

ahab

al e

t al.

(200

5)F

an e

t al.

(200

6)

QSO1

QSO2

RD J1148+5252

7.0R

3.24BM

Mpc

Transverse proximity effect: observationsM

ahab

al e

t al.

(200

5)F

an e

t al.

(200

6)

QSO1

QSO2

RD J1148+5252

7.0R

3.24BM

Mpc

Yu (2005)Shapiro et al. (2006)

White et al. (2003)Wyithe et al. (2005)

Transverse proximity effect: simulations

QSObkgTOT

HII Regions(case B)

Underdense Regions(case A)

Peaks origin:

SG, Ferrara, Fan, Choudhury (2007)

Peak Spectral Density

OUTIN PSDPSD 4d

dNPSD peaks

Transverse proximity effect: observations vs simulations

0R

R

MpcR 2

c

RRtQ

Myr11

R