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SN-GRB Connection: Observations and Questions

Massimo Della Valle INAF-Osservatorio Astrofisico di Arcetri, Firenze Bologna, 1 Giugno, 2006. SN-GRB Connection: Observations and Questions. Outline. Introduction. Outline. Introduction SN 1998bw/GRB 980425, SN 2003dh/GRB 030329, SN 2003lw/GRB 031203. Outline. Introduction

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SN-GRB Connection: Observations and Questions

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  1. Massimo Della Valle INAF-Osservatorio Astrofisico di Arcetri, Firenze Bologna, 1 Giugno, 2006 SN-GRB Connection: Observations and Questions

  2. Outline • Introduction

  3. Outline • Introduction • SN 1998bw/GRB 980425, SN 2003dh/GRB 030329, SN 2003lw/GRB 031203

  4. Outline • Introduction • SN 1998bw/GRB 980425, SN 2003dh/GRB 030329, SN 2003lw/GRB 031203 • Bumps (SN 2002lt & SN 2005nc)

  5. Outline • Introduction • SN 1998bw/GRB 980425, SN 2003dh/GRB 030329, SN 2003lw/GRB 031203 • Bumps (SN 2002lt & SN 2005nc) • SNe-Ibc & Hypernova & GRBs rates

  6. Outline • Introduction • SN 1998bw/GRB 980425, SN 2003dh/GRB 030329, SN 2003lw/GRB 031203 • Bumps (SN 2002lt & SN 2005nc) • SNe-Ibc & Hypernova & GRBs rates • Time lag SN-GRBs

  7. Outline • Introduction • SN 1998bw/GRB 980425, SN 2003dh/GRB 030329, SN 2003lw/GRB 031203 • Bumps (SN 2002lt & SN 2005nc) • SNe-Ibc & Hypernova & GRBs rates • Time lag SN-GRBs • GRB hosts

  8. Outline • Introduction • SN 1998bw/GRB 980425, SN 2003dh/GRB 030329, SN 2003lw/GRB 031203 • Bumps (SN 2002lt & SN 2005nc) • SNe-Ibc & Hypernova & GRBs rates • Time lag SN-GRBs • GRB hosts • Discussion & Conclusions

  9. Outline • Introduction • SN 1998bw/GRB 980425, SN 2003dh/GRB 030329, SN 2003lw/GRB 031203 • Bumps (SN 2002lt & SN 2005nc) • SNe-Ibc & Hypernova & GRBs rates • Time lag SN-GRBs • GRB hosts • Discussion & Conclusions • Recent (exciting) Results

  10. Gamma-ray bursts: prompt emission “Brief (< 100 sec) and intense (~10-6 erg/cm2/s) flashes ofsoft (~100 keV) gamma-ray radiation” Temporal beahviour:wide variety dt << T Highly structured Single pulse

  11. Long and short GRBs GRBs duration:(0.01 ÷ 100) s The distribution isbimodal Hardness/duration correlation: short bursts are harder Paciesas et al. 2000 All the results I will presentconcern thelong-durationclass of GRBs!

  12. Afterglows Long-lived counterparts at X-ray, optical, IR and radio wavelengths Discovery: GRB 970228 by the BeppoSAX satellite Costa et al. 1997 Optical counterpartssoon after van Paradijs et al. 1999

  13. Jakobsson et al. 2005

  14. Clues about progenitors The distance is ~a few Gpc  3.11015 cm Observed flux105/-6 erg cm2 s1 g-luminosity: 1051-54 erg

  15. Energetic Scale: Jets or Sphere • GRB 990123 has been detected by the robotic telescope ROTSE, 22s and 47s after the g-ray trigger at V~11.7 and 8.9, respectively. At z=1.6, the isotropic energy release implies MV ~-35 and a global energetic budget comparable to >Mc2 • All GRBs could be collimated events, with opening angles q~ 5-10 degrees (break in the power law decay of the afterglows, polarization)

  16. Jet break time tbreak Jet opening angle  And in fact the jet effect on the light curve was observed in several GRBs. Here is an example. Due to its nature the jet break time measured from the observations (i.e. monitoring) of the burst afterglow allows to estimate the physical aperture of the GRB jet. “Jet break”

  17. “True” energetics: correcting the energyes derived with the assumption that GRBs are isotropic the energy crisis is relaxed. Moreover the typical energetics clusters around a similar value of 10^51 erg which is by far more standard also in comparison to other astro sources. Isotropic equivalent energy Etrue = Eiso (1 – cos ) Frail et al. 2001

  18. X-ray Flashes

  19. Probable Sequence of GRB Events • The central engine emits a large amount of energy. • Most of that energy accelerates a small mass (~10-5 M) to speeds > 99.99% of lightspeed (G~100/500) • Collisions between different shells of ejected debris creates the gamma rays. • Collisions between ejected debris and interstellar gas create the afterglow.

  20. observer The energy escapes in the form of jets… Dense cloud Kinetic Energy …and the colliding shells give rise to the GRB GRB location <1014 cm Shock dissipation The progenitors collapses or coalesceces, forming a spinning BH Progenitor location:<108 cm Afterglow Afterglow location <1018 cm

  21. SNe & GRBs Facts • ‘Early Gamma-Rays from Supernovae’ (Colgate 1968 & 1974) • GRB 980425 SN 1998bw (Galama et al. 1998)

  22. SN 1998bw was discovered on NTT images of ESO 184 G82 at z=0.0085 • The GRB and the SN appeared spatially (P~10-4/-5) and temporally coincident Dt=+0.7d -2.0d (Iwamoto et al. 1998) • SN 1998bw rivalswith SN 1991T: MB =-19.5 To achieve such a luminosity about 0.5-0.7 M of Ni have to be synthesized in the explosion. This is unprecedented for Core Collapse events (less than 0.1 M ) • The radio emitting shell was expanding at (mildly) relativistic velocities G~1.8 (Kulkarni et al. 1998; Weiler et al. 1999)

  23. Patat et al. 2001

  24. Patat et al. 2001 Mg I [Ca II] Na I [O I] Ca II O I

  25. Patat et al. 2001

  26. Pec Type Ic SNe • Broad lines • Large Kinetic Energy • “Hypernovae” (only SN1998bw was associated with a GRB) Narrow lines • “normal” KE (1051) • Normal SN Ic

  27. Pec Type Ic SNe = Hypernovae • Broad lines • Large Kinetic Energy • “Hypernovae” (only SN1998bw was associated with a GRB) Narrow lines • “normal” KE (1051) • Normal SN Ic

  28. Light Curves of Supernovae & Hypernovae Brightness alone should not be used to define a hypernova, whose main characteristic is the high Ek~1052 ergs (see broad spectral feautures)

  29. E ~ 30×1051ergs E ~ 1×1051ergs SN 1998bw SN 1987A =

  30. Circumstantial evidence: The Bumps 1999-2003(Bloom et al. 1999) Della Valle et al. 2006 Della Valle et al. 2003 (MISTICI Collaboration)

  31. Are the bumps representative of signatures of incipient SNe? Or they can be produced by different phenomena as dust echoes or thermal re-emission of the afterglow or thermal radiation from a pre-existing SN remnant(e.g. Esin & Blandfors 2000; Waxman & Draine 2000; Dermer 2003)

  32. Ca The spectrum of the afterglow associated with GRB 021211, obtained during the bump, reveals the presence of a broad absorption feature (FWHM~150 A), blueshifted by ~15000 km/s, which has been identified with CaII H+K  SUPERNOVA 2002lt Della Valle et al. 2003

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