ガンマ線バーストで読み解く太古の宇宙井岡邦仁(Cosmophysics Group, IPNS, KEK)
E=mc²原子爆弾GRB ~1052erg
太陽が一生かけて出すエネルギーを数秒で放出GRBは宇宙一明るい謎の天体
Luminosity > >msec GRB ～1000 events/yr isotropic ～200 keV, nonthermal 10 -³s～10³s : Short, Long The most luminous objects ~105¹erg/s Afterglow X Opt → Redshift Radio SN Ibc
~1day
Time
optically-thick光度内部衝撃波ISM外部衝撃波[>100 Kinetic energy GRB Shock dissipation Afterglow時間
Bloom+(99)他のモデルもありえる
Broad line Within a few days
GRBのジェットが外層を突き破っているはず
Supernova Short GRB No-SN GRB
Massive star origin ⇒ High redshift GRBs
COSMIC TIME LINE
Like QSO
FROM THE DARK AGES ...
After the emission of the cosmic microwave background radiation (about 400,000 years after the big bang), the universe grew increasingly cold and dark. But cosmic structure gradually Like SN Star formation Reionization Metal Dark energy Larson&Bromm 02 GRBs are useful for probing high z
FIGURE 1.  Cumulative distributions of the limiting redshifts at which the 15 GRBs with well-determined redshifts and published peak photon number fluxes would be detectable by BATSE and HETE-2, and by Swift. Lamb&Reichart 01, Ciardi&Loeb 00
Swift T90~225s中性度xHJ<0.60 (95%CL)母銀河DLA log[Nʰɪ]~21.6重元素[C/H]=-2.4,[O/H]=-2.3, [Si/H]=-2.6,[S/H]=-1.0
πe² f αλα n h ( ζs ) ≈ 6.5×105 xH1 m cH ( z, ) Ω h | || Ωm 0.03 /\ 0.3 ´ 1+ z. 10 Damping Wing ⇒×HIの下限ではなく値が分かる1. GRBは明るい2. No proximity effect (電離領域が小さい) 3.母銀河は暗くてよい(バイアスが少ない) 4.冪的スペクトル将来的には色々な視線方向⇒Topology
ちなみにN(HI) ⇒ Escape fraction ~ 0.02±0.02  Chen+ 07
SKA CO (low) ALMA HD CO (high) [Ol] ⇒Physical conditions in PopIII & early PopII, although challenging log v [Hz]
Potentially High-z ~50% are dark GRBs Bromm&Loeb 06 (Strong chemical feedback - ~10% @z>5 0.1GRB/yr ⇒ z~30 First GRB @z~60 Depend on SFR, L-function, spectrum, efficiency, feedback
3%(4/163) @z>5 Z http://raunvis.hi.is/~pja/GRBsample.html
Bad news: •初期明るいものでも1日後には皆と同じ•No reverse shock? Good news: •Naked-eye burst Extinction corrected. Thin gray: the pre-Swift sample Red: Golden Sample; Blue: Silver Sample; Black: Bronze Sample Vertical lines: time where the optical luminosity was examined
Figure 3: The R-band magnitude of the optical afterglows as a function of the time after the burst at which the spectroscopic observations were ob- tained. Only included are Swift bursts for which we have measured the redshift (using primarily the VLT, but also NOT, WHT and GEMINI). The colour bar at the top indicates the col- our code for the measured redshifts. The dashed line marks a magnitude of R = 20 which is roughly the spectro- scopic limit for 2–4-m telescopes for detecting absorption lines. As seen, most afterglows are fainter than this limit when observable. Fynbo+ 07
Shock emission reverse shock forward shockなぜかあまり受かっていないB dominated? IR flash?
GRB080319B peaked at Vmag~5.3 : Naked-eye GRB (裸眼GRB) Time-dilation+L ∞ t 2 High-zでも明るい7時間後には大きな望遠鏡でもスペクトルが取れなくなった
Typical GRB photon energy Yonetoku+KI(03)
Ep(1+z) [keV]
Liang-Zhang関係1.94 t. -1.24 Luminosity-variability
z>10 GRBs have been detected SFR continues to increase until z～ 10
GRBの母銀河～LMC ~Star formationを担う銀河angles). The symbols are color-coded with the mass ranges as in Fig. 1. The error bars in redshift show the width of the redshift bins used. The error bars in the SFRD combine shot noise and mass-completeness corrections. Both the sampling and the spectroscopic completeness corrections were applied. The squares are the values found locally by Brinchmann et al. (2004) converted according to our assumed IMF and dust correction. The compilation made by Hopkins (2004), where all the values are converted to a (Ω ν = 0.3, Ω ν = 0.7, h = 0.7) cosmology, are overplotted with diamonds. The solid line is the fit derived by Cole et al. (2001) assuming A v = 0.6.
star forming blue faint small irregular low metallicity
GRBは銀河のより明るい所で⇒より重い星(O stars) GRB Hostは小さく暗い⇒低金属?
Low metallicity (⇒ small, faint & irregular) Zcrit~0.15Z。? We are safe the most-right circled point, which is GRB 030 recently claimed by Stanek et al. (2006).  We have done the same analysis, using a much larger sample, and the γ-ray energies E iso provided by Amati (2006) and Amati et al. We are (2007), assuming isotropic emission. (The correlation is not confirmed (Figure 17), not even for the subsample of 5 hosts not safe!? used by Stanek et al. (2006). In fact, this is mainly carried by the metallicity of the GRB 030329 host, for which Stanek et al. (2006) found 12 + log(O/H) = 7.9 using the R23 calibrator.  We derived a more reliable O3N2 metallicity of 12 + log(O/H) = 8.25. Modjaz+(07)
SN Ic ⇒ H, He外層がない外層を星風で飛ばすと回転が落ちるしかし回転はジェット生成に必要(だろう)低金属⇒星風少高速回転⇒子午面対流により全体がCOコアに連星⇒伴星が外層をはがし，合体時に角運動量を与える
Figure 2: The panel on the left shows a schematic x-ray lightcurve with the following four segments: a prompt emission phase, a steep decline phase, a plateau phase, and a post-plateau phase.  For the three GRBs considered in this work, the last phase has a steep and sudden decline. The panel on the right out- lines our proposal for how the different segments in the LC are related to the accretion of corresponding zones in the progenitor star. The radii ( r ) and spin parameters ( f n = Ω/Ω k ) of the various zones are estimated from the x-ray data.
GRBは大質量星団から~400-800pc離れたところ⇒ ~100km/sで飛び出た?
Equivalent width GRB070125 Low Mg II and inferred HI is in typical halos Offset d>27kpc In a compact star-forming cluster? GRB071003 (Perley+ 08)
そもそもZero-metal hostは観測できるのか？金属-質量関係⇒ホストはlow mass ⇒吸収小、しかも暗いz~a fewでもfollow upできない？ Zero-metal host High-density star-forming regionこういう場合がHalo GRB? Hostは暗いZero-metal hostがLAEだった場合も気になる
11 Jun 2008 GBM: 0.008-30MeV, 8sr, 1ºres LAT: 0.02-300GeV, 2.5sr, 5º-5’res
Dermi Gamma-ray Space Telescopeたった4日でEGRET1年分！
Energy Threshold of MAGIC ecker et al. (2006) GRB γ-ray Infra Red Background γ Can measure the amount of IR bg y up to 0.7 cosmological distance
31 GRBs per 1st month (⇒ 372/yr) Sensitivity as predicted (若干多い？) Within a few degrees of Swift calculations
Typical GRB photon energy Yonetoku+KI(03)
Ep(1+z) [keV]

v flux depends on GRB rate
Developments in the Swift era - GRB 050904 @ z=6.3 - z-distribution ⇒ ~10%? @z>5 - Distance indicators - Afterglow (Naked-eye GRB, Few optical flashes) - Low metal host GRB cosmology in the Fermi+Swift era - Star formation rate - Reionization - Chemical evolution (atom, molecule, dust) - Dark energy - IR background - Magnetic field (Faraday rotation, Pair echo), ...