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New Views of Compact Object Mergers Via Short Gamma-Ray Bursts

New Views of Compact Object Mergers Via Short Gamma-Ray Bursts. Derek B. Fox Astronomy & Astrophysics Penn State University. New Views of the Universe –  KICP December 11, 2005. Four Afterglows: 050509B : Swift BAT+XRT 050709 : HETE, Chandra , Ground, HST

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New Views of Compact Object Mergers Via Short Gamma-Ray Bursts

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  1. New Views of Compact Object Mergers Via Short Gamma-Ray Bursts Derek B. Fox Astronomy & Astrophysics Penn State University New Views of the Universe – KICP December 11, 2005

  2. Four Afterglows: 050509B: Swift BAT+XRT 050709: HETE, Chandra, Ground, HST 050724: Swift BAT+XRT, Ground, VLA, Chandra 050813: Swift BAT+XRT Nature - 6 Oct 2005

  3. 5 Four Afterglows: 050509B: Swift BAT+XRT 050709: HETE, Chandra, Ground, HST 050724: Swift BAT+XRT, Ground, VLA, Chandra 050813: Swift BAT+XRT +051210 – Swift BAT+XRT+… Nature - 6 Oct 2005

  4. Eichler, Livio, Piran & Schramm 1991: • Well-known GW wave source • Known GRB model, but: • Short bursts • Featureless spectra • R-process elements • Associated neutrino burst

  5. Short Bursts as Compact Object Mergers

  6. Evidence for mergers Circumstantial: • Old stellar populations • No associated supernovae • Energetics • 100x less than long burst / collapsar (but see: 050813) • 1000x greater than the magnetar giant flare (27 Dec 2004) • Afterglow energy comparable • Okay for NS-NS, NS-BH And possibly: • Offsets from host galaxies • Very old population GRB 050509B (HST)

  7. Evidence for mergers Circumstantial: • Old stellar populations • No associated supernovae • Energetics • 100x less than long burst / collapsar (but see: 050813) • 1000x greater than the magnetar giant flare (27 Dec 2004) • Afterglow energy comparable • Okay for NS-NS, NS-BH And possibly: • Offsets from host galaxies • Very old population GRB 050509B (HST)

  8. GRB 050509B: Keck/Subaru Kulkarni et al. 2005 Error radius = 9.3 arcsec

  9. GRB 050509B: HST Imaging Host galaxy: • Giant elliptical (one of 2 cD galaxies in cluster) • Member of z=0.225 cluster • L = 1.5 L* • SFR < 0.1 M yr-1 GRB 050509B (HST)

  10. GRB 050509B Host Galaxy z=0.225 SFR < 0.1 M yr-1 Bloom et al. 2005

  11. GRB 050724: Radio, NIR, Chandra Berger et al. 2005

  12. Red elliptical z=0.258 L=1.6 L* SFR<0.03 M yr-1 Kulkarni & Cameron

  13. GRB 050724: Gemini Spectra z=0.257 Berger et al. 2005

  14. GRB 050813 Host Cluster Error circle is original XRT localization

  15. GRB 050813 Imaging • Galaxies “B” and “C” are at z=0.72 (Prochaska et al. 2005) • BUT! • Galaxy cluster in vicinity has z~1.8 (Gladders et al., in prep.) • One likely cluster member is found in XRT circle • No spectra as yet XRT B C 10”

  16. GRB 051210 Host Cluster (?) During meeting! • APM cluster at ~8’ distance (Berger & Fox, GCN 4316) • z~0.114 (Dalton et al. 1997) • Optical/radio searches ongoing Cluster X-ray BAT

  17. Evidence for mergers Circumstantial: • Old stellar populations • No associated supernovae • Energetics • 100x less than long burst / collapsar (but see: 050813) • 1000x greater than the magnetar giant flare (27 Dec 2004) • Afterglow energy comparable • Okay for NS-NS, NS-BH And possibly: • Offsets from host galaxies • Very old population GRB 050509B (HST)

  18. GRB 050709: HST Movie 4 epochs 6-35 days F814W Exp=6360 s Blue dwarf irregular galaxy z=0.16 L=0.1 L* SFR > 0.2 M yr-1 Fox et al. 2005

  19. No SN / 050709 Fox et al. 2005 & Hjorth et al. 2005b

  20. Hjorth et al. 2005a (Ground) No SN / 050509B HST Kulkarni et al. 2005 (HST) IAB > 27.7 mag

  21. Evidence for mergers Circumstantial: • Old stellar populations • No associated supernovae • Energetics • 100x less than long burst / collapsar (but see: 050813) • 1000x greater than the magnetar giant flare (27 Dec 2004) • Afterglow energy comparable • Okay for NS-NS, NS-BH And possibly: • Offsets from host galaxies • Very old population GRB 050509B (HST)

  22. Adapted from Fox et al. 2005

  23. Evidence for mergers Circumstantial: • Old stellar populations • No associated supernovae • Energetics • 100x less than long burst / collapsar (but see: 050813) • 1000x greater than the magnetar giant flare (27 Dec 2004) • Afterglow energy comparable • Okay for NS-NS, NS-BH And possibly: • Offsets from host galaxies • Very old population GRB 050509B (HST)

  24. Merger alternatives Collapsar and All-Magnetar models are in trouble. What about: • Multiple source populations • Generic product of BH+Disk • Magnetars present at some level • GRB 050709 in a blue dwarf star-forming galaxy • Varieties of compact-object merger • NS-NS vs. NS-BH • BH-BH (Blandford) • New ideas • Accretion-Induced collapse of NS to BH (MacFadyen, Ramirez-Ruiz & Zhang 2005) – accomodates 100-s long X-ray flares MacFadyen et al. 2005

  25. From Bursts to Rates Nakar, Gal-Yam & Fox astro-ph/0511254 Guetta & Piran astro-ph/0511239

  26. Limiting distances for LIGO K.Thorne / NSF Review

  27. Binary NS Lifetimes • 8 relativistic pulsar binary systems • 2 discovered since 2003: • PSR J0737-3039A @ 87 Myr • PSR J1906+0746 @ ~300 Myr • Merger rate dominated by short-lived systems • Lifetime distribution like –1 (flat in log-space) 1/H0 Champion et al. 2004 + PSR J1906+0746

  28. Binary NS Lifetimes Kalogera et al. 2004: • Minimal rate is 7 LIGO-I events kyr–1 • Maximal rate is very sensitive to new discoveries (e.g. PSR J1906+0746) • Estimated range: 7 to 122 kyr–1 (95% c.l.) • Max. one event per 8 years for LIGO-I Kalogera et al. 2004

  29. SHB Rates & Lifetimes • Start with: • Cosmic SFR(z) • BATSE catalog of burst fluences • Guesses at luminosity and lifetime distributions • Add: 1. SHB redshifts (Swift, HETE, IPN) 2. Or matched SHB redshifts + luminosities at a fixed threshold (Swift) 3. Estimate of burst beaming Guetta & Piran 2005

  30. BATSE SHB Fluences Guetta & Piran 2005

  31. SHBs Old and New Old error boxes: 1 cluster (z=0.09), one bright galaxy (z=0.14), and two empty error boxes (z>0.25) – Gal-Yam et al. 2005

  32. Jet Break / 050709 30:1 beaming Fox et al. 2005 & Hjorth et al. 2005b

  33. Progenitor lifetimes • Begin with star-formation rate SFR(z) • Single power-law luminosity function allows use of all redshifts • Test various progenitor lifetime distributions •  ~ 6 Gyr for narrow log-normal distributions • Inconsistent with –1 distribution (red line) Nakar, Gal-Yam & Fox 2005

  34. Progenitor lifetimes • Begin with star-formation rate SFR(z) • Single power-law luminosity function allows use of all redshifts • Test various progenitor lifetime distributions •  ~ 6 Gyr for narrow log-normal distributions • Inconsistent with –1 distribution (red line) Guetta & Piran 2005

  35. Lifetimes & Luminosities Nakar, Gal-Yam & Fox 2005

  36. Lifetimes & Luminosities Nakar, Gal-Yam & Fox 2005

  37. Lifetimes & Luminosities z=0.72 -> 1.8 • z=0.114 Nakar, Gal-Yam & Fox 2005

  38. Lifetimes & Luminosities z=0.72 -> 1.8 • z=0.114 Nakar, Gal-Yam & Fox 2005

  39. SHBs and LIGO • Long progenitor lifetimes and a high local rate • R ≈ 10 Gpc-3 yr-1 for NS-NS with no beaming and no extrapolation to lower fluxes • R > 300 Gpc-3 yr-1 with 30:1 beaming • At limit of 1047 erg s-1 (Tanvir et al. 2005): R=105 Gpc-3 yr-1 • Max. 3 LIGO-I events yr–1; 0.3 yr–1 more likely • Compare: 0.007–0.122 yr–1 from pulsars • NS-BH or BH-BH models result in even higher rates GRB 050709

  40. New Views of Compact Object Mergers

  41. New Views of Compact Object Mergers • Do compact object mergers produce a strong EM signal? • What is the local rate? • GW detection: LIGO, Virgo… • r-process elements • Where & when are they happening? • Host types & host offsets • Progenitor lifetimes & systemic velocities • Are the explosions beamed? • Do they expel significant quantities of nucleon-rich ejecta? • X-ray flaring • SN-like signal • Nakar, Gal-Yam & Fox 2005

  42. New Views of Compact Object Mergers • Do compact object mergers produce a strong EM signal? • What is the local rate? • GW detection: LIGO, Virgo… • r-process elements • Where & when are they happening? • Host types & host offsets • Progenitor lifetimes & systemic velocities • Are the explosions beamed? • Do they expel significant quantities of nucleon-rich ejecta? • X-ray flaring • SN-like signal  Short bursts  LIGO-I detections feasible  Majority elliptical + clusters  > 3 Gyr  1/fb ~ 30 ?Theory still young (Kulkarni 2005) • Nakar, Gal-Yam & Fox 2005

  43. New Views of Compact Object Mergers Progress will require: • More Swift redshifts, host galaxies, host clusters • More beaming constraints • Evaluation of Swift BAT thresholds or: • LIGO-I Science Run 5 – in progress • Nakar, Gal-Yam & Fox 2005

  44. Caltech-NRAO GRB Collaboration S.R. Kulkarni, S.B. Cenko, A.M. Soderberg, P.B. Cameron, A. Gal-Yam, E. Nakar, D.-S. Moon, M.M. Kasliwal, F.A. Harrison at Caltech D.A. Frail (NRAO), P.A. Price (UH IfA), T. Piran (Hebrew U.), B. Schmidt (ANU), B. Penprase (Pomona), H.-S. Park (LLNL) Carnegie Observatories E. Berger, M. Gladders, E. Persson Swift Team Penn State: J. Racusin, D.N. Burrows, J. Nousek, P. Mészáros, L. Gou GSFC: C. Markwardt, T. Sakamoto UCL: A. Blustin, M. Page SHBs with HST P. Kumar (UT), A. Panaitescu (LANL), R. Chevalier (UVA), A. MacFadyen (IAS) Collaborators

  45. M. Roth, Carnegie D. J. Sand, Caltech S. Shectman, Carnegie M. Takada, Tohuku U. T. Totani, Kyoto U. W. T. Vestrand, LANL D. Watson, Copenhagen R. White, LANL P. Wozniak, LANL J. Wren, LANL B. L. Lee, U. Toronto P. J. McCarthy, Carnegie D. C. Murphy, Carnegie S. E. Persson, Carnegie B. A. Peterson, ANU M. M. Phillips, Carnegie J. Rich, ANU M. Rauch, Carnegie K. Roth, Gemini Obs & Coauthors K. Aoki, NAOJ L. L. Cowie, UH IfA A. Dey, NOAO S. Evans, LANL H. Furusawa, TIT K. C. Hurley, Berkeley N. Kawai, TIT G. Kosugi, NAOJ W. Krzeminski, Carnegie D. C. Leonard, Caltech

  46. The End

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