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Gamma-Ray Bursts & High Energy Astrophysics Kunihito Ioka (KEK) 井岡 邦仁.

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Presentation on theme: "Gamma-Ray Bursts & High Energy Astrophysics Kunihito Ioka (KEK) 井岡 邦仁."— Presentation transcript:

1 Gamma-Ray Bursts & High Energy Astrophysics Kunihito Ioka (KEK) 井岡 邦仁

2 Universe Quantum mechanics  x  p ≥ ℏ General relativity R BH =2GM/c 2 Various scales ⇒ Order estimate Ultimate goal of Astrophysics is to reveal all cosmic phenomena based on physics g/cm 3 cm Atom  =ћ/cL 4 Uncertainty limit Black hole limit  =c 2 /2GL 2 Solar system Sun Galaxy Universe Neutron star Human Quark Nucleon White dwarf Cluster

3 Cosmic jet L~10 51 erg/s~10 44 W » 10 6 W (man-made) AGN ( Active Galactic Nuclei ) Microquasar Pulsar GRB Big Puzzle ~ M ☉ BH ~10M ☉ BH Neutron star Current Energy Man-made accelerator BH formation?

4 Cosmic ray High energy particles (proton, heavy nuclei) pervade the universe Origin is unknown Up to ~10 20 eV » eV (man-made) If 1g matter turns into eV cosmic ray, we can supply our electric power for 10 5 yr! 1 particle/km 2 /century Bhattacharjee&Sigl 00 LHC Cosmic ray spectrum eVGeV Flux

5 GRB = = Sun ~10 33 g GRB ~10 52 erg Atomic bomb In ~sec, GRB release energy Sun emit over lifetime GRB is the most luminous object E=mc 2 (by Einstein) ~1kg

6 Astronomical observation Light curve Spectrum Sky position Too small size Observation+Physics ⇒ We understand cosmic phenomena Photon (  ) Multi-wavelength: Optical (eV) + Radio (  eV), Microwave (meV), Infrared (eV), X-ray (keV),  -ray (MeV)

7 GRB observation >msec Luminosity Time ~ 1000 events/yr Isotropic sky distribution ~ 200 keV, nonthermal s ~ 10 3 s : Short, Long GRB Afterglow X Opt Radio Cosmological distance Redshift Supernova ~1day ~10sec The most luminous ~10 51 erg/s Distance unknown ⇒ True energy unknown

8 Paradox? msec x c ~ 300km erg/s x msec ~ erg MeV  -ray number density > cm -3 Interaction length ~( x10 29 ) -1 cm ~10 -4 cm < 300km  -ray can not escape?  e+e+ e-e-

9 99.99% of light speed Lorentz factor Unique solution

10 Blue-shift  1MeV 10keV MeV=10 6 eV keV=10 3 eV m e c 2 ~MeV Comoving frame Observer frame Similar to the Dopplar effect for a crossing silen Low energy  can not produce e ±

11 Standard model Central Engine Massive star SN Internal shock ? Inter stellar medium External shock v>99.99%c 光度 GRB 時間 Afterglow Kinetic energy ↓ Shock dissipation

12 GRB ≈ BH formation GRB jet breaks out of massive stellar envelope msec x c ~ 300km ~ BH radius Why BH launches relativistic jet? ?

13 Multi-messenger Light curve Spectrum Sky position Too small size Photon (  ) + Other particles Photon (meV-MeV) + High energy  (MeV-100TeV) Cosmic ray (GeV eV) Neutrino (MeV eV) Gravitational wave (nHz-kHz)

14 Fermi has launched! 11 Jun 2008, GLAST→Fermi GBM: MeV, 8sr, 1 o res LAT: GeV, 2.5sr, 5 o -5’res LAT first all-sky map Only 4day data = 1 yr data by previous mission

15 GBM First GRBs 31 GRBs per 1 st month ( ⇒ 372/yr) Slightly more than predicted Within a few degrees of Swift calculations

16 Blue-shift  1MeV 10keV MeV=10 6 eV keV=10 3 eV m e c 2 ~MeV Comoving frame Observer frame Similar to the Dopplar effect for a crossing silen Low energy  can not produce e ±

17 Blue-shift  1GeV MeV=10 6 eV keV=10 3 eV m e c 2 ~MeV Comoving frame Observer frame High energy  can produce e ± ⇒  flux is suppressed 10MeV

18 e ± cutoff and line Photon spectrum KI+ 07 Murase&KI e ± cutoff energy ⇒ Jet velocity 2. e ± line ⇒ e ± abundance (⇒ Jet properties ⇒ Central engine) energy Luminosity

19 High energy proton Jet likely contains (proton, heavy nuclei) + ( , e ± ) cutoff Photon spectrum Luminosity ~GeV (10 9 eV) Energy >10 20 eV Proton spectrum cutoff Proton interacts with  more weakly than  Pion (  ) mass > e mass ⇒ Higher energy cutoff

20 Cosmic ray from GRB 1 particle/km 2 /century Bhattacharjee&Sigl 00 GRB could be the origin of eV cosmic ray! Cosmic ray composition ⇒ Jet composition (p, Fe?) ⇒ Central engine GRB energy generation rate ~ CR energy generation rate

21 High energy neutrino Murase,KI+(06) Neutrino spectrum proton n  ++ ++ e+e+  e ⇒ High energy (~5% x  proton ) ⇒ Proton fraction ⇒ Central engine Strong penetration Not delayed CR origin  appearance Limitting speed Equivalence principle

22 IceCube On-going Completion by pole V~km 3

23 Gravitational wave GW can directly “see” the central engine Transparent for GW Short GRB: origin unknown Amplitude Time Long GRB Charge motion ⇒ Photon Mass motion ⇒ GW (v=c) (ripple of the space-time) Waveform ⇔ Mass, Radius, …

24 Direct detection Free mass separation changes GW  x/x~GM/r~ GR test: Novel prize Short GRB origin Nuclear physics Laser interferometers TAMA LIGO VIRGO GEO ~km

25 Summary GRB: Most luminous object Multi-wavelength obs. ⇒ Massive star, Relativistic jet, BH/NS Multi-messenger obs. High energy  Cosmic Ray Neutrino Gravitational wave ⇒ Central engine (BH formation), Jet, … High Energy Astrophysics Unexpected may be waiting

26 Livingston plot Planck scale in ~190 yr (J/ ,  ) (gluon) (N =3) (W ±,Z) (top) Man-made accelerator is already saturating Cosmic accelerator could expand the energy frontier Center-of-Mass Energy Year ?


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