1. GReat Bu ’ s GRB 2004 / 11 2 GRB GRB

2. Early Mission History 1960s, the Vela series Burst And Transient Source Experiment (on the CGRO, launched in 1991) BeppoSAX (launched in 1996/4/30)– provide a much more accurate location HETE– failed in 1996

3. GRB910421

4. 1967/7/2 the first observation 1973 publish “Model burst” Distance: 1)galactic disc ~10 2 pc 2)halo~10 4 pc 3)cosmological~Mpc For now 1)isotropic distribution 2)redshift determination(~30 now) 3)Angular distrubution  strong suggest a cosmological origion!!

5. Z-known GRBs

6. So…. Huge energy E iso ~10 51-54 erg Rapid temporal variability on time scales of ms  compact object However, due to γ+γ  e+ + e- optical depth should be >> 1, non-thermal spectrum  optical thin Compactness problem

7. The “fire ball” Large concentration of electromagnetic radiation in small region of space with small fraction of baryons Sudden release of high intensity gamma- rays produces e + e - pairs which create an opaque photon-lepton “fireball”

8. The solution?? The relativistic motion ( with Γ ≧ 100 ) of the emitting region GRB are produced when an UR energy flow is converted to radiation in an optically thin region

9. GRB all star GRB970228 Afterglow, x-ray,optical counterpart, XT RT (a breakthrough) GRB970508 Redshift,absorption lines (FeII MgII), radio counterpart GRB971214 Host galaxy GRB980425 SN association(SN1998bw) (z=0.0085, the “closet”) GRB990123 most energetic ( E iso ~3 X 10 54 erg ) optical counterpart (by ROTSE) GRB030325 polarzation GRB030329 SN association(SN2003dh)

11. Adopt from SCIENCE@NASA

12. Summary of observation

13. Observation (I) --GRB E iso Burst rate in 1991-2000 (CGRO operation period) 1/day (~1/10 6-7 yr/galaxy) Duration T 90 :5%~95% in the 50-300keV

14. Observation (II) --GRB Spectrum Non-thermal No clear observational evidence for the existence of spectral lines

15. Observation (III) - afterglow Lightcurves Well fitted by power-laws ~5 GRB has line features in the early X- ray afterglow Some of them “Break” (low energy poewer index ~2) Offset from the center of the hot galaxy Host galaxy (025~Z~4.5): are typically low mass, faint galaxies (R~25) with active star formation region

17. several re-brightenings, varying power law indices

18. Observation (IV) - afterglow GRB/SN connection red excess,”SN bump”: GRB980326, GRB011121 GRB980425 / SN1998bw : within the error box GRB030329 / SN2003dh: very similar spectrum with that in SN1998bw case “super” Type Ic

19. Types of SNe according to the spectrum with H = SN II without H = SN I with Si = SN Ia without Si but with He = SN Ib without Si and without He = SN Ic The energy source for SN Ia is nuclear; for the others is gravitational

21. The lack of a measured redsift SNIc Best fit : Z~0.95

23. Spectral evolution

24. Observation (V) - afterglow Polarization MNRAS 309,L7 1999 Consider a magnetic field completely tangled in the plane of the shock front, but with a high degree of coherence in the orthogonal direction

25. Γ >>1, no polarization Γ ~ 1/(θ c + θ 0 ) Γ <1/(θ c - θ 0 ) see only part of the circle centred on θ 0 Γ  1 light aberration vanishes, The observe magnetic field is Completed tangled and Polarization disappears Two maxima in the polarization light curve, the first for The horizontial component and the second for the vertical one!!

26. GRB030325

27. Oh, Theory

28. Model forest SGRs as a hint ?? Relativistic dust crash energetically into the solar wind Comets falling onto NSs Precessing jets from pulsars Canonballs from supernovae Jet-disk in a binary system Magnetar bubble collapse NS collapse to a strange star Collapse to a BH caused by accretion Supermassive BH formation Evaporating BHs

29. The “ fireball ” again GRBs occur through the dissipation of the kinetic energy of a relativistic expanding fire ball γ-ray emission mechanisms

30. The shape of things Time variability (~milliesecond) R~ CΓ∆T  compact object Duration 10 -2 s ~ 10 3 s Energy Eiso~10 51-54 (for z-known GRBs) Beaming Rates, R~1/10 6-7 yr/galaxy if beamed…..

31. The internal-external model Time-varying outflow makes different Γ(>100) shells

32. When a faster shell catch up with a slower one: Kinetic energy  internal energy (internal shock )  radiation (accelerated electrons interact with the ambient magnetic field ) internal shock  GRB external forward shock  afterglow

35. The “inner engine” Binary NS merge WD-NS, NS-BH merge failed supernova (Collapsar)

36. Collapsar – a BH is born 1993, by Woosley et al. “Failed supernova” Iron core collapse  BH MHD jet

37. ApJ 524:262 1999

39. The jet is erupting through the surface of the star. Blue represents regions of low mass concentration, red and yellow are denser. Note the blue and red striations behind the head of the jet. These are bounded by internal shocks. Adopted from GSFC, NASA

40. Make story complete — asymmetric supernova 2000, by wheeler et al. The generation of jets

41. Make story more complete — Wolf-Reyet star Wolf-Rayet stars are hot (25-50,000+ degrees K), massive stars (20+ solar mass) with a high rate of mass loss. Strong, broad emission lines (with equivalent widths up to 1000Å!) arise from the winds of material being blown off the stars. Wolf-Rayets stars are divided into 3 classes based on their spectra, WN stars (nitrogen dominant, some carbon), WC stars (carbon dominant, no nitrogen), WO stars with C/O < 1.

42. The whole story…. To make a collapsar need three essential components: 1)Wolf-Rayet star 2)A rotating stellar core 3)A core collapse that failed to produce a successful supernova

43. Summary

44. Conclusion Multi-origion MHD Gravitational wave Polarization TeV photon observation GRB 970828 no OT, “dark burst”  be obscured by dust in their host galaxy  associated with massive sar formation??

45. The unified model?? astro-ph/0410728

46. Reference and Special Thanks Many of content are adopted from “Jochen Greiner Homepage” ( http://www.mpe.mpg.de/~jcg/ )http://www.mpe.mpg.de/~jcg/ Romanian Report in Phisics, Vol.56 No.2 P204, 2004 Valeriu Tudose et al. ASTRONOMY, October 2004 Others….