simona gallerani constraining reionization through quasar and gamma ray burst absorption spectra in...
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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
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