GRB多波長放射で切り開く暗黒の宇宙
SKA
GRBs for UNravelling the Dark Ages Mission
井上進(京大理)
ALMA
分子
ダスト
SPICA
TMT
再電離
(磁場)
金属
CTA ASTRO-H
high-z GRB afterglows: expectations
z measurement
from Ly break:
JANUS z~<13
GUNDAM z~<?
Subaru z~<20
TMT z~<40
天文月報
102, 248 (2009)
first star epoch
z~100-10 未知との遭遇
Pop 3 =metal/dust-free, H2+HD-cooling
assume: no metal/dust, B field, CR, turbulence, DM heating
1st HII region -> IGM reionization
1st SN -> 1st metal/dust (+CR+B)
1st BH -> 1st QSO
Pop 2 =metal/dust-cooling
1st sun -> 1st planet, life, human!
観測ほとんど皆無 (WMAPのみ)
1st gen.はわかったとされている
2nd gen.研究に移行
Yoshida, Omukai & Hernquist 08
cosmic star formation rate deduced from GRB rate
from GRB rate
Kistler+ 09
from HUDF
JANUS/GUNDAMでよりhigh-zへ
直接観測と相補的
cosmic reionization epoch
z>7 現在のフロンティア
When? early? late? two-epoch?
How?
topology?
What? Pop III? Pop II?
mini-QSOs?
dark matter decay?
So what?
suppression of
dwarf galaxy
formation
Madau 07
reionization: IGM HI (+ HII) from Lyprofile
z=6.295
McQuinn+ 08
Ly damping wing profile
mean IGM HI + host galaxy HI + host HII
宇宙再電離
すばる、TMTで各成分を分離
よりhigh-zへ(WMAP, Planckと重なる時期)
UV background from gamma-ray absorption
g + g → e+ + eE e
e.g. TeV + 1eV (IR)
100 GeV + 10 eV (UV)
high-z UV背景放射:ガンマ線吸収で識別
SI+ 10 MN 404, 1938
CTA(Fermiの後継)でz~20 GRBまで観測可能 Y. Inoue, SI+, in prep.
gamma-ray opacity
cosmic star formation rate
high-z UV background
below Ly edge e<13.6 eV
- does not ionize HI, weakly absorbed
- reasonably uniform
- important for gg absorption
- direct measure of UV emissivity
(indep. of escape fraction,
IGM clumping factor)
above Ly edge
e>13.6 eV
- ionizes HI, strongly absorbed
- highly non-uniform
- negligible for gg absorption
metal abundances
GRB 050904 z=6.295
Kawai+ 06, Totani+ 06
母銀河の金属組成、運動学
よりhigh-zへ
kinematics
D’Elia+ 09
GRB 080319B z=0.937
- multiple velocity components
- variable line ratio (UV pumping)
VLT/UVES res. ~4 km/s @4500A
- 1.9km/s @9000A
metal abundances GRB 090926A z=2.1071
ground
D’Elia+ arXiv:1007.5357
VLT/X-shooter 0.3-2.5um R=10000
FeII
fine struc.
X/H~3x10-3-10-2
SiII
X-ray absorption lines/edges
Campana+ 06
星生成領域スケールの組成
遠方まで観測可能?
ダストの影響なし
がH, Heの情報なし
<-> 光赤外と相補的
EDGE/XENIA
E~0.2-2 keV E~3 eV Seff~1000 cm2
z=1 GRB
Piro+ 07
-> more from D. Hartmann
z=7 GRB
E=0.3-10 keV E=7 eV Seff=210 cm2
simulations by Bamba (see also Kawai, Yonetoku+, Kyoto conf.)
ASTRO-H
log NH=22 (Zsolar)
Si
log NH=23
Si
S
Fe
z=1
bright [email protected]=10ks
5e-10 erg/cm2/s
integ. 10ks
スザクとは違うのだよ、スザクとは!
ASTRO-H
E=0.3-10 keV E=7 eV Seff=210 cm2
see also Kawai, Yonetoku+, Kyoto conf.
log NH=22 (Zsolar)
z=6
bright [email protected]=10ks
4e-11 erg/cm2/s
integ. 10ks
Fe
log NH=23
z measurement
for dark bursts
<- JANUS alert
E~0.2-2 keV E~3 eV Seff~1000 cm2
XENIA
z=1
early [email protected]=1ks
1e-9 erg/cm2/s
integ. 1ks
Ne
Fe
Mg
Si
log NH=22 (Zsolar)
S
O
log NH=23
O
E~0.2-2 keV E~3 eV Seff~1000 cm2
XENIA
log NH=22 (Zsolar)
Si
z=6
early [email protected]=1ks
5e-10 erg/cm2/s
integ. 1ks
log NH=23
Fe
metal abundances at low metallicity
nucleosynthesis by low metal. SN/HN
Kobayashi+ 06
CNO: mass loss
-elements: pair-instability SN
Ti, Zn: entropy in SN core -> explosion physics
Mn: SN Ia contribution
molecules electronic absorption bands
GRB 080607 z=3.063
Prochaska+ 09
Keck/LRIS R=1000-4000
log NHI=22.70
log NH2=21.2
log NCO=16.5
分子=星形成の原材料
よりhigh-zへ?
collapse of zero/low-metallicity star forming clouds
collapsing zero/low-metal. protostellar clouds
T minimum -> fragmentation
H2
Omukai+ 05 model
dust
H2+HD
[Z/H]<-6: Mfrag~103MQ Pop 3
-3<[Z/H]<-5: Mfrag~0.1-100MQ Pop 2
[Z/H]crit=-5+-1
HD molecules Q 1232+082 z=2.3377 Ivanchik+ arXiv:1002.2107
VLT/UVES R=45000
N(HD)/N(H2)
=7.1(+3.2 -2.2)x10-5
primordial molecules
electronic absorption bands
cold H2:
912-1110A (11.2-13.6 eV)
vib. excited H2:
1110-1650 A (7.5-11.2 eV)
c.f. ambient H2 excited by GRB UV
Draine 00, Draine & Hao 02
similar for HD?
N~1018-1020 cm-2
foreground massive star
UV pumped H2
excited H2
massive
star
GRB
rdiss
probe individual Pop III
newly-born massive stars?
atomic/molecular absorption lines
SI, Omukai & Ciardi
2007 MNRAS 380, 1715
• CO (low) SKA
probe physical
conditions (different J)
• HD
• CO (high)
• [OI]
ALMA
probe Pop III
Pop III->II transition
回転順位線
より高柱密度領域
TMTと相補的
チャレンジングだろうが
やってみよう
dust
GRB 071025 z~5
Perley+ 10
- extinction feature
- best fit with high-z
QSO extinc. curve
(Maiolino+ 04)
ダスト:
Pop II星形成への
遷移に本質的?
TMTでよりhigh-zへ
Pop III ダストの性質も?
absorption by first dust
(optical depth at fragmentation)
pair instability
SN
based on first dust models of Schneider+ 06
TMT (+SPICA)で
Pop 3 -> Pop 2 遷移を探れる?
ダストの性質も?
zero-metal SN II
intergalactic/interstellar magnetic fields at high-z
B fields in Pop III star forming regions
B~10-16-10-14 G on pc scales
IGM B generation at high-z
cosmic reionization fronts
B~10-20-10-16 G
B profile
nHI
B
ngas
T
Xu+ 08
mean B vs z
Gnedin+ 00
also Langer+ 05
“pair echos” (delayed secondary emission)
probe of intergalactic magnetic fields
Plaga 95 (original idea)
sensitive to very weak
intergalactic magnetic fields
GRB
MeV
g ~TeV
B~10-20-10-16 G
e-
IR
e+
CMB
B
g ~GeV
CMB
g
delay
MeV
evolving echo flux
CTA sens.
fix Eiso=1054 erg, z=10, Emax=10 TeV
B=10-15G
assume low EBL
(0.1x CF model)
observationally challenging, but marginally detectable by CTA
Takahashi, SI, Ichiki & Nakamura arXiv:1007.5363
Pop 3 HII regions
- large r~<100 pc
- low density n~0.1 cm-3
- flat profile
Can be probed through
afterglow evolution?
Whalen+ 04
also Kitayama+ 04
まとめ
GRBは宇宙で最も明るい多色光源 有効利用しよう
特にz>10 first star epochは未開拓 GRBで切り拓く
調べられる/られそうなこと:
z 測定、星形成史、再電離史、
金属組成、運動学、分子、ダスト、磁場…
課題:Pop III GRB? その兆候は?
多波長のシナジー:
SKA, ALMA, SPICA, ASTRO-H, CTA…
JANUS and/or GUNDAMを上げよう
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GRB多波長放射で切り開く暗黒の宇宙