230 likes | 393 Views
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?.
E N D
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? • 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, GCNCirc. 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
Short duration GRB • Duration of T90 less than 2 seconds • No counterparts • A separate class of GRBs • Possible Distant (< 30 Mpc) SGR?
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 time BATSE: DISCSC+PREB – 64ms, To-2.048, To+ ~150 s
BATSE 2514 (930905)Power spectrum, Periodogram Power Reduced 2 Frequency, Hz
Anomalous X-ray Pulsars(V. M. Kaspi., F. P. Gavriil, 2004), HXMB
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