gamma-ray bursts & high energy astrophysics
DESCRIPTION
Gamma-Ray Bursts & High Energy Astrophysics. Kunihito Ioka (KEK) 井岡 邦仁. Universe. g/cm 3. 10 20. Quark Nucleon. Neutron star. Quantum mechanics D x D p ≥ ℏ General relativity R BH =2GM/c 2 Various scales ⇒ Order estimate. 10 10. White dwarf. Atom. Sun. 10 0. - PowerPoint PPT PresentationTRANSCRIPT
Gamma-Ray Bursts &High Energy Astrophysics
Kunihito Ioka (KEK)井岡 邦仁
UniverseQuantum mechanics Dx Dp ≥ ℏGeneral relativity RBH=2GM/c2
Various scales ⇒ Order estimate
Ultimate goal ofAstrophysics is to reveal all cosmic phenomena based on physics
10301020101010010-1010-30
10-20
10-10
100
1010
1020
g/cm3
cm
Atom
r=ћ/cL4
Uncertainty lim
it
Black hole limit
r=c 2/2GL 2
Solar system
Sun
Galaxy
Universe
Neutron star
Human
QuarkNucleon
White dwarf
Cluster
Cosmic jet
L~1051erg/s~1044W» 106W (man-made)
AGN ( Active Galactic Nuclei )
Microquasar
Pulsar
GRB
Big Puzzle
~106-9M☉BH
~10M☉BH
Neutron starC
urre
ntEnergy
Man-made accelerator
BH formation?
Cosmic rayHigh energy particles(proton, heavy nuclei)pervade the universe
Origin is unknown
Up to ~1020eV » 1013eV (man-made)
If 1g matter turns into 1020eV cosmic ray, we can supply our electric power for 105yr!
1 particle/km2/century
Bhattacharjee&Sigl 00
LHC
Cosmic rayspectrum
1020eVGeV
Flux
GRB
= =Sun~1033g
GRB~1052ergAtomic bomb
In ~sec, GRB release energy Sun emit over lifetime
GRB is the most luminous object
E=mc2 (by Einstein)
~1kg
Astronomical observationLight curve
SpectrumSky
position
Too small size
Observation+Physics ⇒ We understand cosmic phenomena
Photon (g)
Multi-wavelength: Optical (eV)
+ Radio (meV), Microwave (meV),Infrared (eV), X-ray (keV), g-ray (MeV)
GRB observation>msecLuminosity
Time
~ 1000 events/yrIsotropic sky distribution~ 200 keV, nonthermal10-3s ~ 103s : Short, Long
GRBAfterglow
XOptRadio
Cosmologicaldistance
Redshift
Supernova
~1day~10sec
The mostluminous
~1051 erg/s
Distance unknown True energy unknown⇒
Paradox?msec x c ~ 300km
1051erg/sx msec~ 1048erg
e egg
MeV g-ray numberdensity > 1029cm-3
Interaction length~(10-25x1029)-1cm~10-4cm < 300km
g-ray can not escape?g g
e+ e-
99.99% of light speed
2
1 1001 v c
Lorentz factor
Unique solution
Blue-shift
~100
1MeV10keVMeV=106eVkeV=103eVmec2~MeV
Comoving frame Observer frame
Similar to the Dopplar effect for a crossing silenLow energy g can not produce e±
Standard model
Central Engine
Massive star
SN
Internal shock
? Inter stellarmedium
Externalshock
v>99.99%c光度
GRB時間
AfterglowKinetic energy↓
Shock dissipation
GRB ≈ BH formationGRB jet breaks out of massive stellar envelope
msec x c ~ 300km ~ BH radius
Why BH launches relativistic jet?
?
Multi-messengerLight curve
SpectrumSky
position
Too small size
Photon (g)
+ Other particles
Photon (meV-MeV) +High energy g (MeV-100TeV)Cosmic ray (GeV-1020eV)Neutrino (MeV-1019eV)Gravitational wave (nHz-kHz)
Fermi has launched!11 Jun 2008, GLAST→FermiGBM: 0.01-30MeV, 8sr, 1oresLAT: 0.02-300GeV, 2.5sr, 5o-5’res
LAT first all-sky map
Only 4day data = 1 yr data by previous mission
GBM First GRBs
31 GRBs per 1st month ( 372/yr)⇒Slightly more than predictedWithin a few degrees of Swift calculations
Blue-shift
~100
1MeV10keVMeV=106eVkeV=103eVmec2~MeV
Comoving frame Observer frame
Similar to the Dopplar effect for a crossing silenLow energy g can not produce e±
e egg
Blue-shift
~100
1GeVMeV=106eVkeV=103eVmec2~MeV
Comoving frame Observer frame
High energy g can produce e±
⇒ g flux is suppressed
10MeV
e egg
e± cutoff and line
Photon spectrum
KI+ 07Murase&KI 08
1. e± cutoff energy ⇒ Jet velocity2. e± line ⇒ e± abundance
(⇒ Jet properties ⇒ Central engine)
energy
Luminosityggee
High energy protonJet likely contains (proton, heavy nuclei) + (g, e±)
eegg cutoff
Photonspectrum
Luminosity
~GeV (109eV)Energy
>1020eV
Protonspectrum
0, g pnp cutoff
Proton interacts with g more weakly than gPion () mass > e mass ⇒ Higher energy cutoff
Cosmic ray from GRB
1 particle/km2/century
Bhattacharjee&Sigl 00
GRB could be the originof 1020eV cosmic ray!
Cosmic ray composition⇒ Jet composition (p, Fe?)⇒ Central engine
GRB energy generation rate~ CR energy generation rate
High energy neutrino
Murase,KI+(06)
Neutrino spectrum
protonn
g + m+ e+
nm ne mn ⇒ High energy n(~5% x eproton)⇒ Proton fraction⇒ Central engineStrong penetrationNot delayedCR originn interaction@>TeVt appearanceLimitting n speedEquivalence principle
IceCube
On-goingCompletion by 2011
@South pole
V~km3
Gravitational waveGW can directly “see” the central engine
Transparentfor 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, …
Direct detection
Free mass separation changes
GW
Dx/x~GM/r~10-22
GR test: Novel prizeShort GRB originNuclear physics
Laser interferometers
TAMALIGOVIRGOGEO
~km
SummaryGRB: Most luminous objectMulti-wavelength obs.
⇒ Massive star, Relativistic jet, BH/NS
Multi-messenger obs. High energy g Cosmic Ray Neutrino Gravitational wave
⇒ Central engine (BH formation), Jet, …
High Energy AstrophysicsUnexpected may
be waiting
Livingston plotPlanck scalein ~190 yr
(J/y, t)
(gluon)
(Nn=3)(W±,Z)
(top) Man-made acceleratoris already saturating
Cosmic acceleratorcould expand theenergy frontierC
ente
r-of
-Mas
s E
nerg
y
Year
?