variability of cosmic gamma-ray burst (ii)
DESCRIPTION
Variability of cosmic Gamma-Ray Burst (II). Pozanenko*, V. Loznikov* , R. Preece # *Space Research Institute (IKI) # Dept. of Physics, Univ. of Alabama in Huntsville. Aperiodic variability (I) Coherent variability (II). Short duration GRB connection with SGR?. - PowerPoint PPT PresentationTRANSCRIPT
Variability of cosmic Gamma-Ray Burst (II)
A. Pozanenko*, V. Loznikov* , R. Preece#
*Space Research Institute (IKI)
#Dept. of Physics, Univ. of Alabama in Huntsville
• Aperiodic variability (I)
Coherent variability (II)
Short duration GRB connection with SGR?
• 1982: Mazets, E. P., et al., Ap&SS, 84, 173• 1982 …….. -- ……… 2004• 2004: Boggs, S. et al. SGR1806-20, RHESSI
observations of the 041227 giant flare, GCN Circ. No. 2936
Soft Gamma-ray Repeaters
• Sporadic activity in soft gamma-rays
• 4 SGRs are known (SGR 0526-66, SGR 1900+14, SGR 1627-41, SGR 1806-20)
• Giant Flashes followed long pulsating tail (period 5 – 8 seconds)
• Magnetars = Neutron star with intense magnetic field (> 1014 G)
• Close to the Earth (6-55 Kpc)
Dec.27 2004 Giant Flash of SGR1806-20
• RHESSI, INTEGRAL, Konus-Wind, Swift, Geotail, Helicon-Coronas-F …
Dec.27 2004 Giant Flash of SGR1806-20
RHESSI, K.Hurley et al.
Dec.27 2004 GF of SGR1806-20
Konus-Wind, E.Mazets, et al. Swift, D. Palmer, at al
Dec.27 2004 Giant Flash of SGR1806-20
Short duration GRB
• Duration of T90 less than 2 seconds
• No counterparts
• A separate class of GRBs
• Possible Distant (< 30 Mpc) SGR?
Short duration GRB …
Short GRB time profilesin different energy bands…
Before start:
• Can be Giant Flash from SGR detected from distance about 30 Mpc?
• Is it enough SGRs within 30 Mpc?
• Can be detected Pulsating Tail of distant SGR?
Before start:
• Can be Giant Flash from SGR detected from distance about 30 Mpc? YES
• Is it enough SGRs within 30 Mpc? YES
Can be detected Pulsating Tail of distant SGR???
• The tail energy is the same for all Giant Flashes from SGRs registered
• The ratio of Main Spike of Giant Flashes to the amplitude of pulsation in the tail is varying between 40 and 600
• The amplitude of pulsation depends on geometry, and does not depend on Main Spike
For bright short GRB of BATSE the tail may be detected!
Burst Choice
BATSE:
• Short GRBs (T90 < 2 s)
• Bright GRBs (F64 > 25 phot/cm^2/s)
• 64 ms data • Chan1 ( ~ 25 – 50 keV)• Chan2 ( ~ 50 – 100 keV)• Chan3 ( ~ 100 – 300 keV)• Chan4 ( > 300 keV)
BATSE GRB time profile:Resolution, data types and coverage
To – trigger timeBATSE:DISCSC+PREB – 64ms, To-2.048, To+ ~150 s
BATSE Short GRB F64 > 25 phot/cm^2/s
Id Name comments
0298 910609
0444 910626
2514 930905
3152 94090
3412 950211
3736 950805
6293 970704-
6668 980330 telemetry errors
BATSE 2514 (930905)time profile
Time
0 50 100 150 200
Cou
nts
per0.
064s
Time
0 50 100 150 200
Cou
nts
per0.
064s
102
103
104
BATSE 2514 (930905)Power spectrum, Periodogram
0.01 0.1 1 100
5
10
15
20
#3
0.1 0.2 0.3 0.40
1
2
3
4
5
#3
Pow
erR
educ
ed
2
Frequency, Hz
BATSE 2514 (930905)Phase profile in 100-300 keV
P = 6.425 s
Phase
0.0 0.5 1.0 1.5 2.0 2.5
Cou
nts
perbi
n
57500
58000
58500
59000
59500
60000
Anomalous X-ray Pulsars(V. M. Kaspi., F. P. Gavriil, 2004), HXMB
BATSE Short GRB F64 > 25 phot/cm^2/s
Id Name Possible period
0298 910609 -
0444 910626 1.66 +- 0.05 ?
2514 930905 6.425 +- 0.160
3152 94090 4.00 +- 0.11 ?
3412 950211 6.79 +- 0.17 ?
3736 950805 -
6293 970704- -
6668 980330 Data corrupted in telemetry
Conclusions
• First direct connection of SGR and Short GRB
• Bright galaxy with intensive star formation should be searched within error-box of GRB with (pulsating) tail
• One can estimate distances to Short GRBs which manifest the pulsating tail
• Swift will be able to detect pulsating tale of Short GRB >~ three times more efficiently