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Gamma-ray Bursts and Supernovae

Explore the connection between Gamma-ray Bursts (GRBs) and supernovae (SNe) in this research study. Investigate whether all cosmological GRBs have underlying SNe and if nearby Ib/c SNe have gamma-ray emission. Discover the implications of these findings.

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Gamma-ray Bursts and Supernovae

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  1. Gamma-ray Bursts and Supernovae S. R. Kulkarni California Institute of Technology

  2. Do all cosmological GRBs have an underlying SN? Do all nearby (Ib/c) supernovae have gamma-ray emission? TWO BIG QUESTIONS

  3. Thanks to D. Frail (NRAO) E. Berger, D. Djorgovski, D. Fox, F. Harrison, P. Price, R. Sari, A. Soderberg, S. Yost (Caltech) P. Price & B. Schmidt (ANU) H. S. Park (LLNL) C. Baltay & P. van Dokkum (Yale) R. Chevalier (UVa)

  4. Afterglow Emission: Fireball Model Supernovae: Point Explosion in r-n medium Energy E ~ 1051 erg = 1 FOE Mejecta ~ 1-10 Msun, Lorentz factor ~ 1.01 Sedov solution (non-radiative phase) Supernova remnant (radiative phase) GRBs: Point Explosion in r-n medium Energy E ~ 1-10 FOE Mejecta ~ 10-4 Msun, Lorentz factor ~ 100 Relativistic Sedov solution (Blandford-McKee)

  5. Jet Signatures: Optical/X-ray Piran, Science, 08 Feb 2002

  6. Jet Opening Angles Angles obtained from epoch of breaks in light curves in the homogeneous conical jet framework (Caveat: Structured Jets) • Narrow Opening Angles! only a few degrees wide • Incomplete Statistics for narrow jets

  7. Gamma-ray Energy Release Frail et al. (2001) “Infamous” Frail et al. relation

  8. Kinetic Energy of Fireballs X-ray Afterglow: L_x(t=8hr)*8hr traces E_Kinetic Freedman & Waxman Kumar Application Piro et al. Berger et al. Curiously E_gamma ~ E_Kinetic Berger et al. 2003

  9. GRB host galaxies are star-forming galaxies Bloom PhD 2002 High column density/extincted bursts Galama & Wijers, Djorgovski et al., Piro et al. Circumburst medium: Wind-fed (011121) talks by Frail, Chevalier Most direct evidence comes from associated SNe GRB 980326 Bloom et al. 1999 GRB 970828 Galama et al. 2000, Reichart et al. 1999 GRB 011121 Garnavich et al. 2002, Bloom et al. 2002 GRB 021211 Della Valle et al. 2003 GRB 030329 Stanek et al. 2003 Long Duration GRBs: Massive Stars

  10. Do all cosmological GRBs (c-GRBs) have underlying SNe? • Some c-GRBs have associated bright supernovae • Many either do not have an associated SNe or else V > -19 mag • A wind circumburst medium may not be present around all GRBs

  11. Do all nearby (Ib/c) supernovae have gamma-ray emission? Once upon a time (25-April-1998), a non-descript burst of gamma-rays occurred in the Southern hemisphere. Both GRB astronomers and SN astronomers who held each other in contempt were excited and this is how our story begins…

  12. GRB 980425 & SN 1998bw • GRB 980425, a routine GRB, identified by BeppoSAX Pian et al. 1999 • Identified with bright optical SN with very wide absorption lines Galama et al. 1998 • Identified with super-bright radio SN Kulkarni et al. 1998 Host Galaxy, distance 44 Mpc E_gamma ~ 1048 erg (isotropic)

  13. Relativistic Ejecta! High Brightness Temperature for first 3 weeks requires Gamma ~2 to 4 Kulkarni et al. 1998

  14. Synchrotron Emission: Fast Primer Basic Parameters: fm, num, nua, spectral index (p) Example: GRB 030329 (nearest c-GRB) Compute brightness TB and if TB > Teq (1011 K) then pay either in energy or in size. (For 1998bw, the parametric fit of Weiler et al. violates the above limit)

  15. SN 1998bw: Underlying Engine! Chevalier & Li

  16. What is SN 1998bw? • A c-GRB but viewed at an angle. Unlikely. Nakamura; Iwamoto; Granot et al.; Ioka; Salmonson • A supernova with large E_K (and thus relativistic ejecta via whip mechanism) Energetically Challenged ModelMatzner, Tan & McKee • An engine-driven supernova i.e. a low-luminosity GRB Kulkarni et al; Bloom et al; Li & Chevalier We term such nearby SN with gamma-ray emission as supernova-GRBs or s-GRBs

  17. s-GRBs and c-GRBs: Cousins? Berger et al. 2003

  18. f-GRBs: a new sub-class of c-GRBs? Afterglow of GRB 980327 and GRB 980519 were already fading rapidly (t^-2). We term such GRBs as “f-GRBs” (for GRBs with rapidly fading afterglow) Bloom, Frail & Kulkarni 2003

  19. GRB 030329: an f-GRB? Price et al. (2003, submitted to Nature)

  20. GRB 991216: Narrow & Wide Jets? • Differing decay index(X-ray, optical & radio) • Optical data shows t_jet~1day (Halpern et al) • A narrow angle jet (X-ray and optical) + A wide angle jet (radio) Frail et al. 1999

  21. Our Working Hypothesis • Major observational difference between ordinary SN and GRBs is the presence of relativistic ejecta. • We suggest that only an underlying ENGINE can drive significant relativistic ejecta. DIRECT TRACERS: synchrotron emission strong afterglow emission INDIRECT (reliable?) TRACERS: broad optical lines large inferred SN energy release

  22. f-GRBs and wide+narrow jetted GRBs • f-GRBs appear to be systematically possess low E_gamma but much larger energy in the afterglow • The gamma-ray energy release in GRB 991216 is small compared to that inferred for low-Gamma ejecta (from radio observations) • The gamma-ray energy release of GRB 980425 is only 1% of that inferred from radio observations  The energy in relativistic ejecta can vary enormously.

  23. In Summary : c-GRBs, s-GRBs and f-GRBs • A very small fraction (1%) of the local Ib/Ic SNe can be expected to host c-GRBs. • f-GRBs (fast fading afterglows) may constitute a significant fraction of c-GRBs • “s-GRBs” (GRB 980425/1998bw) are arguably a new of Ib/Ic SNe. However, our VLA search for s-GRBs show that these objects are rare, <10%(Berger et al. 2003) • The primary parameter differentiating c-GRGBs, f-GRBs and s-GRBs is the amount of ejecta with large Lorentz factor (relativistic ejecta). • The sum total of local c-GRBs, s-GRBs and f-GRBs is less than 10% of the local Ib/Ic sample (Berger et al.) (Norris 2003 estimate appears too optimistic)

  24. The story is just beginning ….. X-ray Flashes Short hard bursts SWIFT is expected to be launched in December 2003

  25. Backup Slides

  26. Underlying Supernovae Indepth discussion by J. Bloom and T. Matheson

  27. Wind or ISM? • In most afterglows no CLEAR signature for a wind circumstellar medium • Clear case for GRB 021121 (Price et al. 2002)

  28. Sari, Piran, & Narayan 1998 Berger et al. 2000 External Shocks – Afterglows GRB 000301C

  29. Major Clue: Circumstellar Medium • Density ~ r0 (“Interstellar Medium”) Expected if GRBs result from coalescence • Density ~ r-2 (“Wind Medium”) Expected if GRBs arise result from massive stars  Chevalier and Frail talk Note: For GRBs, length ~ 2 * c * t * gamma* gamma . In contrast, for SNRs, length ~ v * t ~ 0.03 * c * t

  30. Diversity in Cosmological High Energy Transients Gamma-ray bursts (GRB) -- peak luminosity in the range 50 to 500 keV -- Short duration (T < 1 second) -- Long Duration (T > a few seconds) X-ray Flashes (XRF) -- peak luminosity in the range below 50 keV

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