ionized
DESCRIPTION
Narrow-Band Imaging surveys at z=7.7 with WIRCam (CFHT) and HAWK-I (VLT) J.-G. Cuby (LAM) Collaborators : B. Cl ément (LAM), P. Hibon (KIAS) J.Willis (Univ. Victoria), C.Lidman (ESO), S.Arnouts (CFHT), JP.Kneib (LAM), C.Willott (CADC),. Ionized. Neutral. Reionized. - PowerPoint PPT PresentationTRANSCRIPT
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Narrow-Band Imaging Narrow-Band Imaging surveys at z=7.7 with WIRCam surveys at z=7.7 with WIRCam
(CFHT) and HAWK-I (VLT)(CFHT) and HAWK-I (VLT)
J.-G. CubyJ.-G. Cuby(LAM)(LAM)
Collaborators : B. Cl Collaborators : B. Clémentément (LAM), P. Hibon (KIAS) J.Willis (Univ. (LAM), P. Hibon (KIAS) J.Willis (Univ. Victoria), C.Lidman (ESO), S.Arnouts (CFHT), JP.Kneib (LAM), Victoria), C.Lidman (ESO), S.Arnouts (CFHT), JP.Kneib (LAM),
C.Willott (CADC), ...C.Willott (CADC), ...
Ionized
Neutral
Reionized
From Carilli
Dark Ages
Age of Enlightenment
Epoch of Reionization
•last phase of cosmic evolution to be tested
•bench-mark in cosmic structure formation indicating the first luminous structures
From Carilli
Re-ionizationRe-ionization
44
When did it start ?When did it start ? When did it end ?When did it end ? What sources caused it, …What sources caused it, …
Gunn-Peterson trough in QSOsGunn-Peterson trough in QSOs GRBsGRBs UVLF & LyUVLF & Ly LF of Ly LF of Ly Emitters (LAEs) Emitters (LAEs) CMBCMB HI 21-cmHI 21-cm
GP trough with QSOsGP trough with QSOs
55
Only traceable until neutral Only traceable until neutral fraction (HI / H) fraction (HI / H) < 10< 10−3−3
Re-ionization with GRBsRe-ionization with GRBs
Totani et al. 2005
DLA model with z=6.295, log NHI = 21.62
From Totani
UVLF & LyUVLF & Ly LF of Ly LF of Ly Emitters (LAEs) Emitters (LAEs)
Current statusCurrent status
77
Lyα LF ( Observed )z=5.7Phot■z=6.6Phot●z=6.6Spec▲z=7.0Spec◆
Lyα Luminosity log[L(Lyα) erg/s]
Nu
mb
er d
ensi
ty lo
g[n
(>L
) M
pc-
3 ]
Decline in n(>L) ・ galaxy evolution?・ increase in HI?・ both?
z=7LAEdetectionlimit
From Ota
Far-UV Luminosity function of LBGs
Data from SDF
Yoshida et al. 2006, ApJ, in press
Shimasaku et al. 2005, PASJ, 57, 447(z=4, 5)
(z=6)
Bright LBGs decrease in number with redshift(see however Iwata et al. 2003, PASJ, 55, 415)
luminosity functions
From Shimasaku
Lyman α luminosity function of LAEs
Data from SXDF
Ouchi, Murozono et al. 2006In prep
Number density of LAEs unchanged over 3<z<6Fraction of ‘young’ galaxies increases with redshift?
Data from SDF
Shimasaku et al. 2006, PASJ, 58, 313(z=5.7)
luminosity functions
From Shimasaku
… but the number density decreases beyond z=5.7
Ouchi et al. 2006, in press
intrinsic evolution of LAEs?Increase in the neutral fraction of the IGM is more likely,
as the change in the far-UV LF is much milder.
Data for z=6.5 : Kashikawa et al. 2006, ApJ, 648, 7 (SDF)
Data for z=5.7 : Shimasaku et al. 2006, PASJ, 58, 313 (SDF) Ouchi et al. in prep (SXDF)
Data for z=7.0 : Iye et al. 2006, Nature, 443, 186 (SDF)
From Shimasaku
Fan et al.2006 ARAARedshift z
Reionization HistoryN
eutr
al F
ract
ion
XH
I
z=7z=6.6Lyα Emitters
Going beyond z = 7Going beyond z = 7
1313
1414
1060 nm 1190 nm
Sky Spectra in Emission and Transmission
z = 7.7 survey with WIRCAMz = 7.7 survey with WIRCAM
The DATAThe DATA
NB 1.06 NB 1.06 m, 40 hrsm, 40 hrs u*, g’, r’, i’, z’u*, g’, r’, i’, z’
CFHT-LS data (D1)CFHT-LS data (D1) J & KsJ & Ks
5 hrs WIRCAM5 hrs WIRCAM 3.6, 4.5 3.6, 4.5 mm
SWIRE (IRAC)SWIRE (IRAC)
1515
1616
Candidate selectionCandidate selectionInstrumentInstrument BandBand Int. time Int. time
(hrs)(hrs)Lim. Mag.Lim. Mag.””
MegaCamMegaCam u*u* 1010 27.427.4
MegaCamMegaCam gg’’ 11.511.5 27.827.8
MegaCamMegaCam rr’’ 2727 27.527.5
MegaCamMegaCam ii’’ 5555 27.327.3
MegaCamMegaCam zz’’ 2626 26.226.2
WIRCamWIRCam NB 1st epochNB 1st epoch 2020 24.824.8
WIRCamWIRCam NB 2nd epochNB 2nd epoch 2020 24.924.9
WIRCamWIRCam NB combinedNB combined 4040 25.225.2
WIRCamWIRCam JJ 4.54.5 24.724.7
WIRCamWIRCam KsKs 5.65.6 24.324.3
IRACIRAC 3.6 µm3.6 µm 33 22.222.2
IRACIRAC 4.5 µm4.5 µm 33 21.521.5Optical – NB > 3Optical – NB > 4 for the brightest objects
Criteria:Criteria: DDetection inetection in NB1, NB2, NB1, NB2,
NB1+2.NB1+2. Non-detection in optical Non-detection in optical
bands (u,g, r, i, z)bands (u,g, r, i, z) u* - NB1.06 > 2.2u* - NB1.06 > 2.2 g’ - NB1.06 > 2.6g’ - NB1.06 > 2.6 r’ - NB1.06 > 2.3r’ - NB1.06 > 2.3 i’ - NB1.06 > 2.1i’ - NB1.06 > 2.1 z’ - NB1.06 > 1.0z’ - NB1.06 > 1.0
J - NB1.06 > -0.5J - NB1.06 > -0.5 A Posteriori Rejection of A Posteriori Rejection of
the contaminantsthe contaminants
1717
A WIRCam candidateA WIRCam candidate
u Chi2 z
NB1+2 J Ks
7 LAE at 7 LAE at z = 7.7 z = 7.7 candidatescandidates
1 LBG at 1 LBG at z > 7 z > 7 candidatecandidate
1818
1919
LF of z = 7.7 LyLF of z = 7.7 Ly LAE LAE
Assumes that the 7 Assumes that the 7 candidates are realcandidates are real
Most serious Most serious candidates build up the candidates build up the bright end of the z=7.7 bright end of the z=7.7 LFLF
-> bright end robust-> bright end robust
Hibon et al. submittedHibon et al. submitted
Possible sources of contaminationPossible sources of contamination
Electronic crosstalkElectronic crosstalk Guide windowsGuide windows
PersistencePersistence NoiseNoise
TransientsTransients 2 epoch data2 epoch data
T-dwarfsT-dwarfs
2020
EROsEROs K band rejectionK band rejection
Low z interlopersLow z interlopers Ha at z = 0.61Ha at z = 0.61 [OIII] at z = 1.1[OIII] at z = 1.1 [OII] at z = 1.8[OII] at z = 1.8
High z (> 7) LBGsHigh z (> 7) LBGs
2121
Example of electronic cross-talk Example of electronic cross-talk on WIRCamon WIRCam
Possible LFs if contaminationPossible LFs if contamination
Samples of 4 objects out of Samples of 4 objects out of 7, assuming 3 contaminants7, assuming 3 contaminants 20 ‘Bright’ samples w two 20 ‘Bright’ samples w two
brightest objectsbrightest objects 10 ‘Intermediate’ samples w/o 10 ‘Intermediate’ samples w/o
brightest but w second brightest but w second brightestbrightest
5 ‘Faint’ samples w/o the two 5 ‘Faint’ samples w/o the two brightest objectsbrightest objects
More evolution in density More evolution in density than in luminosity for ‘Full’, than in luminosity for ‘Full’, ‘Bright’ and ‘Intermediate’ ‘Bright’ and ‘Intermediate’ samplessamples
2222
Bright
IntermediateFaint
Iye et al., z = 6.96
ImplicationsImplications
Using model from Using model from Kobayashi, we Kobayashi, we derive a neutral derive a neutral hydrogen fraction:hydrogen fraction: xxHIHI = 0.4 for the = 0.4 for the
‘Full’ sample‘Full’ sample xxHIHI = 0.6 for the = 0.6 for the
‘Faint’ sample‘Faint’ sample
2323
Lyα Luminosity log[L(Lyα) erg/s]
LAE evolution model (Kobayashi et al.2007)
Num
ber
dens
ity
log[
n(>
L) M
pc-3]
Increase in HI
Lyα LF ( Model vs. Observation )
On going program with HAWK-I (I) On going program with HAWK-I (I) z = 7.7z = 7.7 100 hrs LP100 hrs LP
2008-20092008-2009
4 fields4 fields 2 empty fields2 empty fields 2 clusters2 clusters
2424
2525
On going program with HAWK-I (II)On going program with HAWK-I (II)
Field: Cluster :
4 pointings more efficient in number of targets than a single pointing for texp ~ 100 hrs.
A few 10s of LAEs expected
2626
ConclusionsConclusions
Spectroscopic follow-up (badly needed...)Spectroscopic follow-up (badly needed...) MOIRCS, x-shooterMOIRCS, x-shooter
If bright objects are confirmed, more evolution in density If bright objects are confirmed, more evolution in density than in luminosity (within the Schechter formalism)than in luminosity (within the Schechter formalism)
Future work:Future work: 2008 : HAWK-I2008 : HAWK-I 2009 : VISTA2009 : VISTA
One NB1190 program in UltraVista (5-yr LP)One NB1190 program in UltraVista (5-yr LP)
2013 : JWST2013 : JWST 2018 : ELT (EAGLE)2018 : ELT (EAGLE)