1. The Exceptional GRB/XRF 060218 and its Associated SN 2006aj Jinsong Deng National Astronomical Observatories of China

2. Why is it Exceptional? extremely long duration T 90 ~ 2100 sec (typical GRB ~ 10 – 100 sec) dominated by soft X-ray photons E peak ~ 5 keV  X-ray Flash (typical GRB > 100 keV) under-luminous E iso ~ 6 x 10 49 erg (typical GRB > 10 52 erg) a UV LC bump peaking at ~ 30,000 sec associated with SN 2006aj the 1st clear XRF-SN connection

3. SWIFT Prompt BAT/XRT/UVOT Obs. Campana et al. Nature 06 Aug 31

4. Swift Long-term XRT / UVOT LCs Campana et al. Nature 06 Aug 31 SN 2006aj ?

5. A Low-redshift Drawf Host Galaxy z ~ 0.033 the 2nd closet GRB drawf (fainter than SMC) M(B) ~ -16  ~ 0.01 L *, ~ 10 8 M ⊙ SRF ~ 0.05 M ⊙ yr -1 Mirabal et al. 06 GCN Pian et al. Nature 06 Aug 31 Sollerman et al. 06 A&A Modjaz et al. 06 ApJL Mirabal et al. 06 ApJL SDSS-2 pre-burst

6. The Emergence of SN 2006aj “A Heavenly Gift for the KITP GRB06 Program” –– Alicia Soderberg 2006 No H/He lines  type Ic earliest spectra for any Ibc Masetti et al. VLT Feb 21.05UT, Soderberg et al. Gemini Feb 21.02UT Fugazza et al. TNG Feb 20.93UT, Mirabal et al. MDM Feb 20.10UT, etc

7. Models of  -ray and X-ray Obs. a thermal X-ray comp.+ UV LC bump Campana et al. Nature 06  “Shock break-out” of dense WR wind ? Liang et al. 06: double themal comps. Butler 06: no thermal comp., but Fe emi. lines Li 06: requiring progenitor > 80 R ⊙ too large for WR Ghisellini et al. 06: UV/opt SED consistent with non- thermal X-ray comp., but not the thermal one Fan et al. 06: non-thermal comp due to central engine thermal comp due to jet-cocoon Models for prompt  -ray emi. Dai et al. 06: inverse-Compton scattering of “shock break-out”thermal photons Wang et al. 06: bulk-Compton scattering of “shock break-out” themal photons

8. VLT SN Spectra and LCs Pian al. 2006 Nature submitted Pian et al. Nature 06 Aug 31

9. NAOC SN LCs and Spectra photometry: 80cm TNT spectroscopy: 2.16m consistent with VLT but of low S/N Deng et al. 06 in prep.

10. Spec. Comp. with Other Ibc SNe Mazzali, Deng et al. 2006 Nature submitted Mazzali, Deng et al. Nature 06 Aug 31

11. LC Comp. with Other Ibc SNe Mazzali, Deng et al. 2006 Nature submitted Pian et al. Nature 06 Aug 31

12. Modeling the VLT Spectra much less M & KE than other GRB-SNe M ~ 2 M ⊙, KE ~ 2 x 10 51 erg SNe 1998bw, 2003dh, 2003lw ~ 8 – 13 M ⊙, ~ 30 – 70 x 10 51 erg  hypernovae Mazzali, Deng et al. Nature 06 Aug 31

13. V ph Comp. With other Ibc SNe

14. Modelling the LC Mazzali, Deng et al. 2006 Nature submitted using the same model as for spectra M ~ 2 M ⊙, KE ~ 2 x 10 51 erg M( 56 Ni) ~ 0.2 M ⊙ Mazzali, Deng et al. Nature 06 Aug 31

15. Modelling the Nebular Spectrum obtained on Jul 26 with Keck by Foley et al. our modelling is going on M ~ 2 M ⊙, M( 56 Ni) ~ 0.2 M ⊙ M(O) ~ 1.4 M ⊙

16. KE ~ M MS of SNe and HNe NS BH

17. M( 56 Ni) ~ M MS of SNe and HNe NS BH

18. Radio Comp. with Other Ibc SNe Soderberg al. 2006 in prep. 1000 x less luminous than 030329 10 x less luminous than 980425 early turn-on  on-axis mildly- elativistic (  ) material Soderberg et al. Nature 06 Aug 31

19. Amati E p ~ E iso Correlation 980425 031203 060218 030329 020903 050416a Amati 06 MNRAS, Amati et al. 06 E p ~ E iso 0.5 XRFs 060218, 020903, 050416a & GRB 030329 outliers: GRBs 980425, 031203

20. Different Origins of GRBs and XRFs GRB-connected SNe display heterogeneity SN 98bw-like (large M, large KE) M MS ~ 35 - 50 M ⊙  BH formation  collapsar   large  in relativistic jets  GRB SN 06aj-like (low M, low KE) M MS ~ 20 M ⊙  NS formation  ms magnetar activity   small  in relativistic jets  XRF newborn ms magnetar B > 3 x 10 15 G, P ~ 1 ms  L dipole > 10 50 erg s -1 Usov 92 Nature, Thompson 94 MNRAS, Nakamura 98 P. Theo. Phys., Wheeler 00 ApJ

21. Local Sub-luminous GRBs in all the 7 GRBs with z<0.2, at least 5 are sub-luminous GRB z E iso (erg) SN connction 980425 0.008 1E48 X-ray rich SN 1998bw 060218 0.033 6E49 XRF SN 2006aj 051109B 0.080 4E48 060505 0.089(?) 1.2E49 SN excluded !? 031203 0.105 1E50 X-ray rich SN 2003lw 060614 0.125(?) 8.9E50 SN excluded !? 030329 0.168 1.7E52 X-ray rich SN 2003dh 020903 0.251 2.8E49 XRF possible SN over-population of local sub-luminous GRBs a rate hundrends times that of cosmological GRBs the Sino-French GRB mission Eclair/SVOM will do better in exploring this population than Swift Pian et al. 06 Nature, Soderberg et al. 06 Nature 06, Liang et al. 06, Cobb et al. 06 ApJL