2 - 13 july 2004, erice1 the performance of magic telescope for observation of gamma ray bursts...
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2 - 13 July 2004, Erice 1
The performance of MAGIC Telescope for observation of
Gamma Ray Bursts
Satoko Mizobuchi for MAGIC collaboration
Max-Planck-Institute for physics(Werner-Heisenberg-Institute)
Muenchen
2 - 13 July 2004, Erice 2
Low Energy Threshold
•GRBs originate in cosmological distances•High energy γ-rays are absorbed through the
interaction with infrared photon•Energy cutoff is expected
from 50GeV to 100GeV•Need a detector with low energy threshold!!
MAGIC Effective collection area 103m2~ 105m2 (10GeV-100GeV)
•Need a fast slewing telescope•GRB Duration time: few seconds - several minutes•SWIFT : 5 arc-minutes accuracy within 10 seconds
Fast slewing time
MAGIC Slewing time < 20s
Gamma-Ray Bursts detection by MAGIC
40GeV
10GeV
2 - 13 July 2004, Erice 3
The MAGIC sensitivity and expected prompt GRB spectra
10-10
10-11
MAGIC
10-6
10-7
10-8
10-9
Ref : Prompt GRB spectra : detailed calculations and the effect of pair production
Asaf Pe’er and Eli Waxman astro-ph/0311252 11 Nov 2003
ConditionL = 1052erg εe= εB = 10-0.5, p=3
∆t = 10-2s, Γ= 300 (l´ = 2.5)∆t = 10-3s, Γ= 600 (l´ = 0.8)∆t = 10-4s, Γ= 1000 (l´ = 0.6)
AssumptionLuminosity distance dL = (1+Z) r = 2×1
028
z = 1
10s
100s
2 - 13 July 2004, Erice 4
Epeak
α
β
Energy
Flu
x
BATSE GRB Current Catalog (2702 GRBs)- fluence - duration- light curve (64ms resolutio
n)The spectral catalog (95 bursts)
- amplitude(A), low-energy spectral index (α),high-energy spectral index (β),peak energy (Epeak)
Ref : http://www.batse.msfc.nasa.gov/batse/grb/catalog/current/ , http://cossc.gsfc.nasa.gov/batse/batseburst/sixtyfour_ms/,
Preece R.D., ApJ 496: 849- 862, April 1998, Preece R.D., ApJ Supp., 126, 19-36, Jan 2000
Epeak
β
Information of GRBs detected by BATSE
2 - 13 July 2004, Erice 5
300keV
α
β
Energy
Flu
x Normalize
90
)()300@(
T
FluenceCkeVflux
T90
Fluence
Expected spectrum of GRBs
2 - 13 July 2004, Erice 6
MAGIC (PMT)Index -2.2
10GeV – 20GeV 10.7σ20GeV – 40GeV 16.3σ
BG40Hz
MAGIC observation time
BG20Hz
Observation Start time
Significance > 5 σ Observation start time 15sec – 30sec
10GeV-20GeV
20GeV-40GeV
-2.5 2.0% 3.0%
-2.2 24% 29%
-1.9 41% 42%
Detection capability with MAGIC Telescope
BATSE
2 - 13 July 2004, Erice 7
•With HPD Advanced CameraLarger observable sky x1.7Higher Detection efficiency x1.3
•Predicted number of GRBs by SWIFT Satellite : ~ 200 bursts/year
•Duty Cycle of observation time by MAGIC 14%•Observable sky by MAGIC 15% (zenith angle <45˚)•GRB detection efficiency by MAGIC: >24%
≥1.0 bursts/year
Number of observable GRBs with MAGIC
Preliminary
2 - 13 July 2004, Erice 9
1. BATSE GRB Current Catalogue (2702 bursts)-Fluence -Duration time-Light curve (Time Profile)
2. Assume Power law index -1.9,-2.2 and -2.5 between 300keV and 40GeV energy, estimate Gamma Ray flux at 10-20 GeV, 20-40 GeV energy bins.
3. Convolute MAGIC acceptance with Gamma Ray flux at 10-20GeV, and 20-40GeV
4. Add Expected Hadron shower rates 40Hz, and 80Hz in 10-20GeV and 20-40GeV energy bin.
Estimation of gamma-ray rate at MAGIC energy
Gamma Ray flux at 300keV
Toy Simulation
2 - 13 July 2004, Erice 10
MAGIC
HETE2(2000-)SWIFT(2004.09-)
XMM(1999-)ASTRO-E (2005.02-)Ⅱ
ASCA(1993-2000)ROSAT(1990-1999)
RXTE(1995-)
BeppoSAX(1996-2002)Chandra(1999-)
CGRO(1991-2000)
GLAST(2007.02-)INTEGRAL(2002-)
MAGIC
The energy rangeINTEGRAL
HETE2
SWIFT
2 - 13 July 2004, Erice 11
Shock plasma conditions (6 free parameters)1. Related to the underlying source
• Total luminosity L [erg]• Lorentz factor of the shock plasma Γ• Variability time t∆ [s]
( assumption : thickness of shells is c t )∆2. Related to the microphysics
• Ratio of the magnetic field energy density to the total th
ermal energy• The fraction of the total thermal energy E
which goes into random motions of the electrons
• Power law index d log ne / d log εe = -p
E
UBB
E
Uee
Comoving compactness
∆R : comoving width :comoving number photon density : Thomson cross section
15 tLnRl eT
n
T
Plasma parameters
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