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Konus-Wind 10 years of operating in space 10 years of GRBs observations from the joint Russian-American KONUS-WIND experiment: results and perspectives.

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Presentation on theme: "Konus-Wind 10 years of operating in space 10 years of GRBs observations from the joint Russian-American KONUS-WIND experiment: results and perspectives."— Presentation transcript:

1 Konus-Wind 10 years of operating in space 10 years of GRBs observations from the joint Russian-American KONUS-WIND experiment: results and perspectives E.P.Mazets, R.L.Aptekar, D.D.Frederiks, S.V.Golenetskii, V.N.Il’inskii, V.D.Pal’shin, M.V.Ulanov A.F.Ioffe Physico-Technical Institute, St.Petersburg, Russia T.L.Cline, P.S.Butterworth NASA Goddard Space Flight Center, Greenbelt, Maryland, USA

2 Konus-Wind 10 years of operating in space Main results of the KONUS experiments on the “Venera 11-14” missions (1979-83) A number of types of GRBs with different time history and duration distribution were studied. Short GRBs were indicated as a separate class. Sources of soft repeating bursts were discovered. The energy spectra of GRBs were investigated. A rapid spectral variability was found. Localization of 160 sources of GRBs revealed their isotropic distribution on the celestial sphere.

3 Konus-Wind 10 years of operating in space GRBs bimodal distribution GRBs duration distribution. Data of Konus experiments on Venera 11-14 (1979 – 1983)

4 Konus-Wind 10 years of operating in space GRBs celestial distribution Konus GRBs distributionBATSE GRBs distribution

5 Konus-Wind 10 years of operating in space Wind Instruments

6 Konus-Wind 10 years of operating in space Wind trajectory Wind trajectory during extended mission phase 10: Low-inclination phasing orbit July 2002 to November 2002 XY (ecliptic plane) projection Wind trajectory during extended mission phase 11-13: L1 excursion  L2 excursion  L1 Lissajous orbit (2002-2008+) XY (ecliptic plane) projection

7 Konus-Wind 10 years of operating in space Scientific objectives of Konus-Wind experiment study of GRBs including a determination of their occurence rate above a sensitivity threshold of ~ 10 -7 erg cm -2, detailed measuring of the time histories of bursts with high time resolution of 2 – 64 milliseconds, detailed spectral measurements in the broad energy range of 10 keV – 10 MeV, investigations of a fast spectral variability on a time bin scale of a few milliseconds; precise localization of GRBs by means of an arrival time triangulation method together with other Interplanetary Network (IPN) spacecraft using the Wind s/c as a constant and effective vertex of the IPN; comprehensive study of the Soft Gamma Repeater (SGR) – very rare astrophysical objects in our Galaxy thought to be neutron stars with a huge magnetic field of 10 14 - 10 15 G – including a monitoring of a long-term variations of their activity and waiting for exceptional rare giant flares in SGR’s with energy release up to 10 44 erg; detection and study much more slower gamma-ray transients especially those which are coming from objects believed to contain a black hole.

8 Konus-Wind 10 years of operating in space Konus-Wind Gamma-Ray Burst Experiment on US GGS-Wind spacecraft Two detectors S1 and S2: NaI(Tl) 13 cm diameter, 7.5 cm height, 12.5 cm Be window. Located on opposite faces of spacecraft, observing correspondingly the southern and northern celestial hemispheres Burst mode: Time history analyzer: resolution 2ms – 256 ms, total duration 230s 12 – 50 keV4096 ch 50 – 200 keV4096 ch 200 – 770 keV4096 ch

9 Konus-Wind 10 years of operating in space Instrument description (continue) Pulse Height analyzer: accumulation time 64ms – 8.192 s, duration 79 – 492 s PHA1 12 – 770 keV63 ch quasilog scale PHA2 0.2 – 10 MeV63 ch quasilog scale Background mode: accumulation time 1.47 – 2.94 s Count rate: 12 – 50 keV 50 – 200 keV 200 – 770 keV > 10 MeV

10 Konus-Wind 10 years of operating in space Konus-Wind Summary Joint Russian-American experiment on US GGS-WIND spacecraft Launch: November 1, 1994 Konus-Wind instrument switched on: November 11, 1994 Orbit: beyond the magnetosphere of the Earth Observations: November 11, 1994 –December 18, 2004 ( 3689 days) Gamma ray bursts total2524 Burst mode1419 Background mode1105 Solar flares729

11 Konus-Wind 10 years of operating in space Konus-Wind GRBs GRB 980706a – an example of short hard GRB. E p = 1.6 MeV.

12 Konus-Wind 10 years of operating in space Konus-Wind GRBs GRB 041211 – a recent example of long multipeak hard GRB.

13 Konus-Wind 10 years of operating in space Duration distribution of Konus-Wind trigger GRBs

14 Konus-Wind 10 years of operating in space Fast spectral variability of GRB 991208 KONUS-WIND GRB 991208 T 0 = 16613.263s UT Two pulses with clear spectral evolution

15 Konus-Wind 10 years of operating in space Fast spectral evolution of GRB 991208 Pulse 1Pulse 2

16 Konus-Wind 10 years of operating in space Fast spectral variability of GRB 970828

17 Konus-Wind 10 years of operating in space Konus-Wind-Ulysses-Konus-A localization for GRB 970228 GRB 970228 was localized by BeppoSAX WFC (IAUC 6572) Independent IPN Ulysses/Wind triangulation (IAUC 6593) X-ray and optical transient was found z = 0.695 ± 0.002

18 Konus-Wind 10 years of operating in space Localization of GRB 010109

19 Konus-Wind 10 years of operating in space Konus-Wind observations of Soft Gamma Repeaters Konus-Wind detected more than 150 trigger SGR bursts from 4 SGRs: 1900+14, 1806-20, 1627-41, 1801-23. Numerous SGR bursts were detected in the background mode Giant outbursts were detected from SGR 1900+14 and SGR 1627-41 Series of bursts were detected from SGR 1900+14 and recently from SGR 1806-20 (GCN 2769) Now Konus-Wind continue to register bursts from SGR 1806- 20, which stay in active state

20 Konus-Wind 10 years of operating in space SGR 0526-66 Burst 790306 detected from SGR 0526-66 by Konus on Venera 11

21 Konus-Wind 10 years of operating in space Konus-Wind observations of SGR 1900+14 Burst 790324 - the first burst detected from SGR 1900+14 by Konus on Venera-11 Burst 980902b – a typical burst from SGR 1900+14 detected by Konus- Wind

22 Konus-Wind 10 years of operating in space SGR 1806-20 Burst 040828 – the most intense burst (both in peak flux and fluence) detected by Konus-Wind from this SGR.

23 Konus-Wind 10 years of operating in space SGR 1627-41 An intense burst 980625 from SGR 1627-41 which demonstrates strong spectral evolution typical for this SGR.

24 Konus-Wind 10 years of operating in space Giant outburst on 1998 August 27 (SGR 1900+14) Time and energy characteristics of the August 27 event. Top: Background subtracted light curve of the outburst. Horizontal sections with triangles specify count rates averaged over the period. The sloped dashed line is a plot of exp(-t/  ) for  = 91.5 s. Bottom: Horizontal sections with squares specify kT averaged over the period.

25 Konus-Wind 10 years of operating in space Giant outburst on 1979 March 5 (SGR 0526-66) Time and energy characteristics of the March 5 event. Top: Background subtracted light curve of the outburst. Horizontal sections with triangles specify count rates averaged over the period. The sloped dashed line is a plot of exp(-t/  ) relation for  =100 s. Bottom: Horizontal sections with squares specify kT averaged over the period.

26 Konus-Wind 10 years of operating in space Giant outburst on 1998 June 18 (SGR 1627-41) Time and energy characteristics of the June 18 event. Top: Background subtracted light curve of the outburst. period. The rise time os about 100 ms. Bottom: Spectral evolution during the burst.

27 Konus-Wind 10 years of operating in space New SGR 1801-23 New SGR was discovered by Wind, Kosmos2326, CGRO, and Ulysses Only 2 short bursts from this source were detected up to date Burst 970629b T 0 =23493.221 s UT

28 Konus-Wind 10 years of operating in space Giant outbursts from Gygnus X-1 the Cyg X-1 outburst on 950325 as observed by Konus-Wind The narrow spike at 25,841 s in the beginning of interval B is the GRB that triggered a series of multichannel spectral measurements, covering the entire interval B. The gap after B was caused by the transmission of high- resolution data to the onboard tape recorder. Background levels are indicated by the dashed lines.

29 Konus-Wind 10 years of operating in space Giant outbursts from Gygnus X-1 (continue) Konus F spectrum of the outburst on 950325. The spectrum was accumulated during the decay stage of the flare over 360 s of interval B with moderate statistics. The solid curve is the result of the spectral fit. The spectral shape is consistent with that of the hard state of Cyg X-1.

30 Konus-Wind 10 years of operating in space Giant outbursts from Gygnus X-1 (continue) Konus 15–300 keV photon fluxes (background subtracted) and hardness ratios for the outburst on 020224. The time resolution is 23.552 s.

31 Konus-Wind 10 years of operating in space Konus-Wind observations of GRBs with known redshifts Konus-Wind has been successfully operating since November 1994. Of more than 30 GRBs with known redshifts, Konus- Wind has detected 23 GRBs in the trigger mode and 7 in the background mode. It is the largest subset of GRBs with known redshifts collected by one instrument.

32 Konus-Wind 10 years of operating in space Konus-Wind observations of GRBs with known redshifts: GRB 030329 (z=0.1685) Konus-Wind light curve of the famous GRB 030329. Fluence: (1.74±0.01)×10 -4 erg cm -2. Peak Flux: (2.62±0.04)×10 -5 erg cm -2 s -1 26 high resolution spectra were obtained with E p varies from 30 to 180 keV.

33 Konus-Wind 10 years of operating in space Konus-Wind observations of GRBs with known redshifts Correlation of isotropic equivalent maximal Luminosity with Ep (in the source rest frame) for Konus-Wind GRBs with known redshifts.

34 Konus-Wind 10 years of operating in space Main scientific results of the Konus-Wind experiment in the course of Konus-Wind experiment more than 1400 GRBs were detected in a triggered mode with high time and spectral resolution; Time histories, energy spectra, a fast spectral variability, and inherent correlations in the bursts have been studied; the IPN with Konus-Wind as a basic vertex has precisely localized a large number of GRB sources by triangulation method, producing crucial data for the multiwavelength study of the GRB afterglows with many telescopes, both ground-based and in orbit;

35 Konus-Wind 10 years of operating in space Main scientific results of the Konus-Wind experiment (continue) A comprehensive study of SGRs was carried out. Two new sources, SGR1627-41 and SGR1801-23 were discovered in addition to three known SGRs. The Konus-Wind experiment was succeeded in detailed studying of the huge outburst in SGR1900+14 on August 27, 1998. It was the second observed giant flare in SGRs after the famous March 5, 1979 event in SGR0526-66. Third giant flare was observed from the new SGR1627-41. About more than 300 more common repeating bursts were observed in SGRs at revealed phases of their burst activity; Rare strong and long outbursts from Cygnus X-1 were discovered. Such type of its behavior represents a new feature of gamma-ray emission of binary system contained a black hole.

36 Konus-Wind 10 years of operating in space The Konus-Wind experiment data collection, archiving and dissemination. Obtained information are stored on CD ROM’s at GSFC and at Ioffe Institute. To make it available for scientific community several websites were opened. Time histories of GRB’s given with the time resolution of 64 ms are available though GCN website at GSFC (http://gcn.gsfc.nasa.gov ) immediately after receiving telemetry data on the ground.http://gcn.gsfc.nasa.gov Two complete sets of an accumulated information, “Konus Catalog of Soft Gamma Repeater Activity: 1978 to 2000” and “Konus Catalog of Short GRBs” are presented on the Ioffe Institute websites at http://www.ioffe.rssi.ru/LEA/SGR/Catalog/,and http://www.ioffe.rssi.ru/LEA/shortGRBs/Catalog/, respectively. http://www.ioffe.rssi.ru/LEA/SGR/Catalog/ http://www.ioffe.rssi.ru/LEA/shortGRBs/Catalog/ The complete catalog of all observed GRBs is now in preparation

37 Konus-Wind 10 years of operating in space Perspectives of the Konus-Wind experiment The Konus-Wind experiment remains an important source of time resolved GRB’s spectral data in the wide energy range from 15 keV up to 12 MeV. This information is a real contribution in the GRB’s multiwavelength study as a whole and especially for GRBs detected by SWIFT, since the spectral coverage of the SWIFT BAT instrument is extremely limited (about 20 – 150 keV). Recent developments in our understanding of GRBs suggest that broad-band spectral information about prompt GRB emission can provide important constrains on models.


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