The greatest flare of a Soft Gamma Repeater On December 27 2004 the greatest flare from SGR 1806-20 was detected by many satellites: Swift, RHESSI, Konus-Wind, Coronas-F, Integral, HEND, … 100 times brighter than ever! Palmer et al. Astro-ph/0503030

Подборку оригинальных статей можно найти здесь: http://xray. sai. msu Подборку оригинальных статей можно найти здесь: http://xray.sai.msu.ru/~polar/sci_rev/05_02_15-28.html

Magnetars in the Galaxy 4 SGRs, 8 AXPs, plus candidates, plus radio pulsars with high magnetic fields … Young objects (about 104 yrs). Probably about 10% of all NSs.

Alternative theory Fossil disk Mereghetti, Stella 1995 Van Paradijs et al.1995 Alpar 2001 Marsden et al. 2001 Problems ….. How to generate strong bursts?

Why “magnetars”? dE/dt > dErot/dt By definition: magnetically-powered NSs P-Pdot Direct field measurements (Ibrahim et al.)

Known magnetars AXPs SGRs CXOU 010043.1-72 0526-66 4U 0142+61 1627-41 1 RXS J170849-40 XTE J1810-197 1E 1841-045 AX J1844-0258 1E 2259+586 SGRs 0526-66 1627-41 1806-20 1900+14 +candidates

Magnetic field measurements Direct measurement of the magnetic field of the SGR Spin-down Long periods Ibrahim et al. 2002

Are SGRs and AXPs relatives? SGR-like bursts from AXPs Spectral properties Quiet periods of SGRs (0525-66 since 1983) Gavriil et al. 2002

Historical notes 05 March 1979. Cone experiment. Venera-11,12 (Mazets et al.) Event in LMC. SGR 0520-66. Fluence: about 10-3 erg/cm2 Mazets et al. 1979

Main types of activity of SGRs Weak burst. L<1041 erg/s Intermed. bursts.L=1041–1043 erg/s Giant bursts. L<1045 erg/s Hyperflares. L>1046 erg/s See a review in Woods, Thompson astro-ph/0406133

Common (weak) bursts from SGRS and AXPs Typical burst from SGR 1806-29, SGR 1900+14 and from AXP 1E 2259+586 observed by RXTE (from Woods, Thompson, 2004, astro-ph/0406133) (from Woods, Thompson 2004)

Intermediate SGR bursts Four intermediate bursts. However, the forth is sometimes considered as a giant one (from Woods, Thompson) (from Woods, Thompson 2004)

Giant flare from SGR 1900+14 (27 Aug 1998) Data from Ulysses (figure from Hurley et al. 1999a) Spike 0.35 sec P=5.16 sec L>3 1044 erg/s ETOTAL>1044 erg Influenced the Earth ionosphere Hurley et al. 1999

27 Dec 2004 giant outburst of SGR 1806-20 Spike 0.2 sec Fluence 1 erg/cm2 E(spike)3.5 1046 erg L(spike)1.8 1047 erg/s Long tail (400 s) P=7.65 s E(tail) 1.6 1044 erg Distance 15 kpc

Konus-Wind data om SGR 1806-20 27 Dec 2004 flare Mazets et al. 2005

SGR giant flares vs. GRBs Woods et al.

SGRs and starformation Possibility of a SGR detection outside the Local group of galaxies Starforming galaxies are the best sites for a search <5 Mpc. M82, M83, NGC 253 About 40 Mpc. Arp 299, NGC 3256 Possible candidates in the BATSE catalogue of short GRBs (Popov, Stern 2005)

Theory of magnetars Thompson, Duncan ApJ 408, 194 (1993) Entropy-driven convection in young NSs generate strong magnetic field Twist of magnetic field lines

Magnetars origin (a speculative discussion) Fast rotation is necessary (Thompson, Duncan) Spin-up of a progenitor star in a binary via accretion or synchronization Coalescence About 10% of NSs (Popov, Prokhorov 2005)