1. Early and Late Prompt emission Gabriele Ghisellini INAF-Osservatorio Astronomico di Brera - Italy + UHECRs and Magnetars with the help of D. Burlon, A. Celotti, C. Firmani, F. Fraternali, G. Ghirlanda, D. Lazzati, L. Nava, M. Nardini, F. Tavecchio

2. Very early prompt: Precursors Study of all Swift GRBs with z Initial pulse, weaker and separated from the prompt (i.e. BAT flux below bkg level) Precursors in 15% Burlon+ astro-ph/0806.3076

3. “Precursors” Very long  t Double Burlon+ 2008, astro-ph/0806.3076

4. Not softer, not harder than the rest of prompt Very energetic (factor ~3 less than total) No correlation with delay time >40s15-40s<15s Slope Main Prompt Slope Precursor Energy Main Prompt Energy Precursor They look like the first pulse of the prompt, not a separated component. Why  t so long?

5. Late activity

6. X-ray and optical often behave differently ~same spectrum TATATATA Is this “real” afterglow? i.e. external shock? X-ray

7. Nardini et al., in prep. Optical X-rays TATATATA TA?TA?TA?TA? W h a t i s T A ?

8. Early (normal) prompt: Early (normal) prompt:  >>1 /  j Late prompt: Late prompt:  >1 /  j Late prompt: Late prompt:  =1 /  j Late prompt: Late prompt:  <1 /  j ”real” after- glow Ghisellini et al. 2007 Strong, erratic Smooth After the early prompt, the central engine decreases energy and decreases  monotonically R~10 13 cm

9. Early (normal) prompt: Early (normal) prompt:  >>1 /  j Late prompt: Late prompt:  >1 /  j Late prompt: Late prompt:  =1 /  j Late prompt: Late prompt:  <1 /  j ”real” after- glow Ghisellini et al. 2007 R~10 13 cm TATATATA T jet

10.  ~ t -   /2 t-2t-2t-2t-2 t-3t-3t-3t-3 Time Flux M out ~ t -(      ) /2 TATATATA L   M out ~ t -  

11.  ~ t -   /2 t-2t-2t-2t-2 t-3t-3t-3t-3 Time Flux M out ~ t -(      ) /2 Long lasting engine with two-phase accretion? 1: Very dense torus, large B-field, erratic. 2: Less dense material, smaller B-field, smoother accretion – Fallback? TATATATA L   M out ~ t -   L~ M accr ? Very cheap

12. MacFadyen+ 2001 t -5/3 M from fallback

13. Zhang Woosley Heger 2008 10 6 10 5 10 4 10 3 Time [s] Fallback lasts for quite a long time M from fallback

14. Lazzati+ 2008 t -5/3 From averaging the luminosity of flares in different GRBs

15. Lazzati+ 2008 t -5/4 From averaging the luminosity of flares in different GRBs

16. ~70 Swift GRBs with z

17. t -5/3

18. t -5/4

19. SEDs vs light curvesSEDs vs light curves Tests Log F Log F Log Log optical X-rays

20. SEDs vs light curvesSEDs vs light curves Some GRBs with no plateau: achromatic breaks?Some GRBs with no plateau: achromatic breaks? Tests

21. SEDs vs light curvesSEDs vs light curves Some GRBs with no plateau: achromatic breaks?Some GRBs with no plateau: achromatic breaks? Late ‘jump’ in X-ray light-curves revealing real X-ray afterglowLate ‘jump’ in X-ray light-curves revealing real X-ray afterglow Tests TATATATA Jump=end of late prompt Time X-ray Flux

22. UHECRs, Spiral Galaxies and Magnetars with Ghirlanda, Tavecchio, Fraternali, Pareschi astro—ph/0806.2393

23. 27 Auger Events >57 EeV Auger events 1 EeV=10 18 eV The Auger collaboration, 2007, Science

24. CenA Virgo AGNs from VC-V catalogue If the Galactic plane is excluded, 19 out of 21 events do correlate Auger events The Auger collaboration, 2007, Science

25. HIPASS: ~5000 HI emitting galaxies (21 cm) GG+, 2008

26. Weight for flux and Auger exposure

27. ~72%

29. Cut in distance

30. Cut in luminosity

31. Virgo Centaurus

32. It is not Cen A, it is the Centaurus cluster (>40 Mpc)

33. 100 Mpc

35. F Auger ~ 10 -11 erg cm 2 s -1 Flux for E>57 EeV Easy for AGNs (but they are radio-quiet… no  ) Long `BATSE’ GRBs (too distant) Short `BATSE’ GRBs (flux not enough) Giant Flares of Magnetars (flux not enough) Newly born, fastly spinning Magnetars (!!!, but went unobserved by BATSE) Progenitors

36. Campana et al. 2006 BB Flux Opt-UV GRB 060218 ???

37. Very long, soft, underluminous, nearby (145 Mpc)Very long, soft, underluminous, nearby (145 Mpc) It could not have triggered BATSEIt could not have triggered BATSE Proposed to be a newborn magnetar (Soderberg+ 2007; Toma+ 2007)Proposed to be a newborn magnetar (Soderberg+ 2007; Toma+ 2007) Right rateRight rate

38. Conclusions Precursors? Same as prompt  just first pulse. Why so long quiescent times?Precursors? Same as prompt  just first pulse. Why so long quiescent times? Late prompt with decreasing power and Late prompt with decreasing power and  T A is very easily explainedT A is very easily explained Fallback is long  late prompt “forever”Fallback is long  late prompt “forever” UHECRs correlate with spirals  newly born magnetars? If so, new class of GRBs (2 per yr all sky): similar to GRB 060218: soft, very long, underluminous+SNUHECRs correlate with spirals  newly born magnetars? If so, new class of GRBs (2 per yr all sky): similar to GRB 060218: soft, very long, underluminous+SN

46. Very energetic

47. Nardini et al., in prep. X-rays Optical