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GRB_Fermi-WAM-Kanata_2009May.ppt X X (Exploring (Exploring

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SLIDE 1

GRB_Fermi-WAM-Kanata_2009May.ppt

可視 可視 X線 γ線同時観測で探 線同時観測で探 可視・ 可視・X線・ 線・γ線同時観測で探 線同時観測で探 るγ線バースト 線バースト (Exploring (Exploring GRBs through Optical, X GRBs through Optical, X- GRBs through Optical, X GRBs through Optical, X ray and Gamma ray and Gamma-

  • ray

ray Observations) Observations)

Tsunefumi Tsunefumi Mizuno Mizuno Hiroshima Univ Hiroshima Univ Hiroshima Univ. Hiroshima Univ.

7 May 2009, Tokyo Tech, Japan 7 May 2009, Tokyo Tech, Japan

Tsunefumi Mizuno

1

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GRB_Fermi-WAM-Kanata_2009May.ppt

Outline Outline

  • Fermi Gamma-ray Space Telescope

F i LAT d GBM Fermi LAT and GBM Burst Advocator

  • GRBs seen by Fermi

Overview GRB080916C GRB080916C GRB081024B

  • Kanata Telescope for GRB

Tsunefumi Mizuno

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GRB_Fermi-WAM-Kanata_2009May.ppt

The Fermi Gamma The Fermi Gamma-

  • ray Space Telescope

ray Space Telescope y p p y p p

Launch on 11 June 2008

  • Launch on 11 June 2008
  • LAT (Large Area Telescope)

Energy range: 20 MeV-300 GeV Effective Area: ~8000 cm2 Effective Area: 8000 cm FOV: 2.4 sr (EGRET 0.5 sr) Dead time: 26.5 μs (EGRET 100 ms)

  • GBM (GLAST Burst Monitor)

Consists of 12 NaI and 2 BGO detectors. Energy range: 8 keV – 30 MeV Energy range: 8 keV – 30 MeV Field of view: 9.5 str Initial localization: <15 deg in 2s

Tsunefumi Mizuno

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Spectrum more than 7 energy decades!!

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GRB_Fermi-WAM-Kanata_2009May.ppt

Burst Advocator Burst Advocator

Scientists serve as “Burst Advocator” and cover 24

hrs/day and 7 dyas/week

Japanese B/A consists of young members from 3

institutes; institutes;

Masanori Ohno, Rie Sato (ISAS/JAXA), Yoshitaka Hanabata, Takeshi Uehara and Hiromitsu

Takahashi (Hiroshima Univ ) Takahashi (Hiroshima Univ.),

Takeshi Nakamori, Takashi Shimokawabe (Tokyo

Tech.)

Report on the LAT visibility and check the LAT data Tsunefumi Mizuno

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Successfully issued GCN circular for GRB 090217 and

GRB090323 which occurred during Japanese shift.

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SLIDE 5

GRB_Fermi-WAM-Kanata_2009May.ppt

Fermi Detection of GRBs Fermi Detection of GRBs

  • GBM : GRB detection rate is ~200/yr. (08/11/2008 –

03/10/2009 116 GCN Circulars) 03/10/2009 116 GCN Circulars)

  • LAT : 7 GRBs detected until May 2009 and notified to GCN
  • Circulars. Detection rate is ~10/yr.

GRB080825C (GCN8183, Bouvier et al.) GRB080916C* (GCN8246, Tajima et al.) (Abdo et al. 2009 Sci, 323, 1688)

  • Circulars. Detection rate is 10/yr.

( , j ) (

, , )

GRB081024B (GCN8407, Omodei et al.) (short GRB w/ GeV photons) GRB081215A (GCN8684, McEnery et al.) GRB090217 (GCN8903 Ohno et al ) GRB090217 (GCN8903, Ohno et al.) GRB090323* (GCN9021, Ohno et al.) GRB090328* (GCN9044, McEnery et al.; GCN9077, Cutini et al.)

2 LAT GRBs w/ WAM detection

Tsunefumi Mizuno

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4 GRBs w/ GeV photons 3 GRBs w/ redshift (*) 2 GRBs w/ GCN by Japanease BA

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GRB_Fermi-WAM-Kanata_2009May.ppt

GRB080916C GRB080916C

  • z=4.35 +/- 0.15

(GROND; GCN8257)

8-260 keV

(GROND; GCN8257)

  • More than 3000

LAT photons 145

260 keV-5 MeV

LAT photons, 145 above 100 MeV and 14 above 1 GeV.

LAT (all)

Eh=13.2 GeV

  • Delayed &

>100 MeV

Delayed & temporary extended (t>200s) HE emission

>1 GeV

Tsunefumi Mizuno

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emission

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GRB_Fermi-WAM-Kanata_2009May.ppt

Implications from GR080916C Implications from GR080916C

  • Delayed & Extended HE emissions
  • Fitted by a single Band function.

Eiso ~ 8.3 x 1054 ergs, highest ever

  • bserved. No conclusive evidence
  • f extra component
  • Minimum bulk Lorentz factor

840±40 (from opacity in bin-’b’)

  • EBL effect not included
  • Lorentz invariance violation

– 13.2 GeV @ T0+16.5 s

i M

Pulsar GRB GRB AGN AGN

GRB080916C Planck mass

– MQG> (1.5±0.2) x 1018 GeV/c2, 1/10 of the Plank mass

Tsunefumi Mizuno

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min MQG (GeV)

Pulsar (Kaaret 99) GRB (Ellis 06) GRB (Boggs 04) AGN (Biller 98) AGN (Aharonian 08)

1015 1016 1017 1018 1019

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SLIDE 8

GRB_Fermi-WAM-Kanata_2009May.ppt

GRB081024B GRB081024B

NaI 8 – 260 keV

  • The first non-controversial

short GRB w/ GeV photons

BGO

  • 11 photons above 100 MeV,

Eh=3 GeV no redshift

260 keV – 5 MeV

  • no redshift
  • Single Band function,

delayed HE onset &

LAT all events

delayed HE onset & temporary extended HE emission (common feature among LAT GRBs?)

LAT > 100 MeV

among LAT GRBs?)

  • Γmin~100 (z=0.1), ~700

(z=3.0) (from opacity in bin-

Tsunefumi Mizuno

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  • 4 -2 0 2 4 6 8 10

”b”)

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GRB_Fermi-WAM-Kanata_2009May.ppt

HOWPol HOWPol on Kanata Telescope

  • n Kanata Telescope (1)

(1)

(Hiroshima One-shot Wide-field Polarimeter) ( )

Focus adj. stage Focal mask Filter exchanger Prism exchanger

１露出型偏光撮像（広視野 7’×7’、狭 視野 1’×15’）

Focal mask exchanger CCD dewer Collimator lens Camera lens Shutter and pupil Polarmetric unit exchanger

  • 2008年7月28-31日 ファーストライト

検出効率： B: 8%, V: 20%, R: 30%, I: 28% (望遠鏡、大気込み)

  • 2008年11月4日～ 定常試験観測開始
  • 2008年11月4日～ 定常試験観測開始

器械偏光 ~4% （第三鏡による偏光面回転のみの補正で0.6%精度 が達成） 試験観測 超新星観測が主（GRBアラート対応観測はTRISPECで）

Tsunefumi Mizuno

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試験観測、超新星観測が主（GRBアラ ト対応観測はTRISPECで）

  • 2009年5月3日～ GRBアラート対応自動観測開始
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GRB_Fermi-WAM-Kanata_2009May.ppt

HOWPol HOWPol on Kanata Telescope (2)

  • n Kanata Telescope (2)
  • 2008年度中はHOWPolでのGRB観測は間に合わず

TRISPECでのGRB観測は9例、うち2例でdetected

GRB t_start –t_end Satel. ⊿t comment

  • 080426 13:30:31-13:50:15 Swift, 428 s, Non-detection, shortburst

080506 17:49:26 19:22:30 S ift 185 R 17 5 19 3 (U h i ) 080506 17:49:26-19:22:30 Swift, 185 s, R=17.5-19.3 (Uehara+ in prep) 080810 13:16:23-19:39:17 Swift, 371 s, R=13.9-18.7 (Uehara+ in prep) 080905 12:01:32-12:58:06 Swift, 157 s, Non-detection 081012 13:16:17-14:06:13 Swift, 353 s, Non-detection 081211 15:22:22 15:40:37 S ift 3 6 h N d t ti 081211 15:22:22-15:40:37 Swift, 3.6 hr, Non-detection 081211B 15:47:29-15:49:02 Swift, 14.5 hr, Non-detection 081222 13:09:15-13:21:14 Swift, 8.3 hr, Non-detection 090217 14:20:13-16:00:17 Fermi, 9.4 hr, Cloudy, non-detection 090404 16:02:44-16:21:13 Swift, 374 s, Cloudy, non-detection 090410 18:48:50-19:01:18 Swift, 1.8 hr, Low-altitude, non-detection 090417B 15:31:49-15:38:18 Swift, 706 s, Non-detection 090418 12:35:35 12:38:19 Swift 1 5 hr Cloudy non detection

Tsunefumi Mizuno

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090418 12:35:35-12:38:19 Swift, 1.5 hr, Cloudy, non-detection 090426 12:54:09-13:28:22 Swift, 322 s, non-detection z=2.609 ⊿t は衛星のトリガーから露出開始（t_start）までの経過時間

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SLIDE 11

GRB_Fermi-WAM-Kanata_2009May.ppt

HOWPol HOWPol on Kanata Telescope (3)

  • n Kanata Telescope (3)

GRB 080506：X線フレアと相関し ない可視残光 GRB 080810：ゆっくりと青くなっ ていく可視残光

外 Ｘ線 Ｘ線 可視・近赤外 緑 可視Ｖ 青 近赤Ｊ 水 近赤Ｋｓ

  • 2009年5月3日からGRB対応観測（但し狭視野モード用のウォラ

ト プリズムを視野 ク無し 使用するため背景 カイが ストンプリズムを視野マスク無しで使用するため背景スカイが4 倍高くなり観測限界は悪い）

  • 2009-2010年度 公募研究「明るいガンマ線バースト初期残光の

Tsunefumi Mizuno

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年度 募研究 明 線 初期 光 偏光分光測光同時モニター」にて広視野モード用のウォラスト ンプリズムを導入予定 (川端の講演)

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GRB_Fermi-WAM-Kanata_2009May.ppt

Summary Summary

  • Fermi GBM detects ~0.5GRB/day and LAT ~10 GRBs/year
  • 7 LAT GRBs above 100 MeV

4 GRB / G V h t h t (GRB081024B) 4 GRBs w/ GeV photons, one short (GRB081024B) 2 GRBs w/ WAM detection, 3 w/ redshift

  • GRB080916C w/ maximum E

ever observed

  • GRB080916C w/ maximum Eiso ever observed

14 photons > GeV, Γmin>=900, MQG>1.3x1018 GeV/c2

  • GRB081024B is the first short GRB with photons above 1 GeV.

GRB081024B is the first short GRB with photons above 1 GeV. Γmin=100 (for z=0.1) and 700 (for z=3.0) Single Band function, delayed HE onset and extended HE emission => common feature?

  • HOWPol on Kanata Telescope is now ready (on May 3, 2009)

9 GRBs observed, 2 GRBs detected in 2008/4-2009/3 by TRISPEC

Tsunefumi Mizuno

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GRB_Fermi-WAM-Kanata_2009May.ppt

B k Slid Backup Slides

Tsunefumi Mizuno

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GRB_Fermi-WAM-Kanata_2009May.ppt

Spectral Analysis Spectral Analysis

Spectrum at T0+0.1 – T0+0.8s GBM 2nd pulse (including i h t f maximum energy photon of 3.0 GeV) can be fitted by a Band Function. α= -0.9053 ± 0.203 β= -1.993 ± 0.0768 β Ep = 819.2 ± 547.0 keV No strong evidence of additional high energy component.

Tsunefumi Mizuno

14

g gy p

103 106 (keV) (1GeV) 104 105 102 10 (1MeV)

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SLIDE 15

GRB_Fermi-WAM-Kanata_2009May.ppt

Minimum Lorentz Factor Minimum Lorentz Factor

Use interval b to derive Gamma minimum as described in GRB080916C paper (Abdo et al, 2009) and Asano-san’s talk.

) 1 ( 2 1 4 2 1 1 ) 1 ( 2 1 2 min

) ( ) 1 ( )] ( ) ( ) ) ( ( [

− + − + −

+ Δ = Γ ≥

β β β β β

β σ E E z F E f E z d

c c c L T

Γ

p p ( , )

4 2 min

) ( ) ( )] ( ) ( ) ( [ Δ β c m f t c

e c c T

3 1 1 1 ) 1 ( 2 2

) ( ) ( ) 1 (

−

Δ Δ Γ

β β

β 1 993 0 0768

3 1 ) 1 ( 2 min

) ( ) ( ) 1 (

− −

Δ ≈ Δ = Δ ∝ Γ t t t

β β

β= -1.993 ± 0.0768 Δt : The variability time scale = duration/2 = 0.35sec

Although z is uncertain,

E0 : The maximum photon energy = 3.0GeV. y

Tsunefumi Mizuno

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Although z is uncertain,

Γmin(z=0.1) 100, Γmin(z=3.0) 700

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GRB_Fermi-WAM-Kanata_2009May.ppt

HOWPol on Kanata Telescope (2) HOWPol on Kanata Telescope (2)

  • 2008年12月～ ＧＲＢアラート対応観測開始
  • バーストから100秒以内の偏光観測開始めざす
  • Akerlof & Heather (2007) Statistics of 108 Swift GRBs

40%で光学残光 うちt=1000秒換算での等級が14等,16等,18 等より明るいもの0.9%,4.6%,16.7%

10

990123 060117 061007

1000秒

  • 4年間観測を続けると

1000秒後でも16等より明るいサ ンプルを１個/4年(100-1000sの間

Δp=0.2%

200秒

050922C

15

(V or R or r')

Polarimetry 1min limit Polarimetry 060607A 030329 050525A 050801 060111B

( で偏光の変化を追う) 200sで16等より明るいサンプル を3-4個(10分露出で偏光測定)

1分露出時 分露出時 Δp 0.2% 偏光測定 限界

050820A

20

Magnitude (

y 10min limit Photometry 10min limit 021211

( 露 ) =>年1個程度の偏光観測を期待

仮定： 10分露出時 Tsunefumi Mizuno

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101 102 103 104

Time after burst (sec)

10min limit

発見レート100個/年 高度係数 0.33 (>20度） 夜間係数0.4 晴天係数0.4