Ryo Tsutsui, JGRG 22(2012) Measuring distance with gamma-ray bursts RESCEU SYMPOSIUM ON GENERAL RELATIVITY AND GRAVITATION JGRG 22

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1 Ryo Tsutsui, JGRG 22(2012) Measuring distance with gamma-ray bursts RESCEU SYMPOSIUM ON GENERAL RELATIVITY AND GRAVITATION JGRG 22 November Koshiba Hall, The University of Tokyo, Hongo, Tokyo, Japan

2 Distance measurement with (long) gamma-ray bursts Ryo Tsutsui (RESCEU) on behalf of GRB Cosmology Project and Hi-Z GUNDAM Project JGRG /11/13

3 Table of Contents Brief introduction of gamma-ray bursts previous works and problems for distance measurements with gamma-ray bursts Their improvements and future prospects

4 Table of Contents Brief introduction of gamma-ray bursts previous works and problems for distance measurements with gamma-ray bursts Their improvements and future prospects

5 The simplest picture of long gamma-ray bursts Meszaros 2002 Meszaros 2001 Energy release form central engine Radiation from relativistic jet Lorents factor ~ 100 interaction between shell and interstellar medium

6 Time scale of GRBs 20 sec 40 sec short long 100 sec 400 sec Complex time profile 2 sec Two population Long: core collapse Short: merger?

7 Energy and distance of GRBs Butler & Kocevski 2007

8 Spectra - Luminosity correlation E α Yonetoku et. al., 2004 E β νf ν GRB z<1.7 Peak energy(ep) GRBs are standardizable candles

9 Luminosity of objects in the sky Sun erg/s Type Ia Supernovae erg/s Gamma ray bursts erg/s

10 Table of Contents Brief introduction of gamma-ray bursts previous works and problems for distance measurements with gamma-ray bursts Their improvements and future prospects

11 Distance measurement with GRBs Kodama, RT (Ω m, Ω Λ ) = (0, 1) (0.3, 0.7) Luminosity distance (cm) GRB (z<1.4) GRB (z>1.4) Type Ia SNe Redshift z = (1, 0)

12 Kodama, RT

13 Major origin of error 4(1σ) The upper dashed line is 4 times brighter than the lower one. This means that we have two times uncertainty in distance measurement with Ep-Lp relation.

14 What means Four times 4(1σ) The difference between two P-L relations for Cepheid is comparable with dispersion of the Ep-Lp relation for long GRBs.

15 Result of the classification of Cepheid variable Discovery of two populations result in accurate determination of H0

16 Clues for the existence of sub-classes of long GRBs I Some long GRB are associated with Type Ic SN, but some does not. These events may result in sub structure in the Ep-Lp relation.

17 Clues for the existence of sub-classes for long GRBs II X-ray Count rate The most difficult problem which GRB study is facing. This suggests that there are some populations of long GRB. Diversity of X-ray AG light curve (t~ sec)

18 Table of Contents Brief introduction of gamma-ray bursts previous works and problems for distance measurements with gamma-ray bursts Their improvements and future prospects

19 Toward accurate candles The use of accurate data. Redefinition of Lp in GRB rest frame time. The use of robust statistics and outlier rejection The second parameter : TL=Eiso/Lp Yonetoku, RT, + PASJ, 2010 RT, + PASJ, 2011

20 Two separate populations of long GRBs RT. PASJ in press TL=Eiso/Lp

21 Prompt-afterglow connection no breaks Preliminary steep-shallow normal slow-shallow normal

22 A new scaling law of Type II long GRBs Preliminary Division into sub classes reveals a beautiful scaling law of Type II long GRBs. This relation implies a universal mechanism which governing both of prompt and afterglow emissions.

23 Two separate populations of long GRBs RT. PASJ in press TL=Eiso/Lp

24 Hubble diagram for Type I long GRBs (Ω m, Ω Λ ) = (0, 1) µ,grbs =0.31 µ,sneia =0.26 SNe Ia GRBs outliers The error of LGRBs becomes as small as those of SNe Ia.

25 preliminary Constraint from Type I long GRBs

26 Future mission HiZ-GUNDAM (High-z Gamma-ray bursts for Unraveling the Dark Ages Mission) X-ray Imager (4-100keV) Gamma-ray spectrometer ( keV) Opt-NearIR Telescope ( μm) 80 events/year (40 events for cosmology?)

27 Hubble diagram for Type I long GRBs σωm 0.01 for 100 Type I long GRBs.

28 ODAIBA Hi-Z GUNDAM Project has nothing to do with a famous japanese animation GUMDAM If you go to Odedo-onsen by subway and monorail, you can find big gundam from monorail.

29 Summary We have found sub classes of long GRBs. Division into two classes drastically improve accuracy of distance measurement.

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32 Two distinct spectral model BAND model Cut off power law model CPL Ep is alway higher than Band Ep

33 How to define Lp 1 sec in observer frame 2.7 sec in GRB rest fram τ 2.7 sec is the best resolution for Lp

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