1 / 24

Astroparticle Physics: Primordial Black Holes Quantum Gravity

Astroparticle Physics: Primordial Black Holes Quantum Gravity. Frank Krennrich, Iowa State University. Outline. Primordial Black Holes: - Hawking Radiation - formation scenarios - observational limits

locke
Download Presentation

Astroparticle Physics: Primordial Black Holes Quantum Gravity

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Astroparticle Physics: Primordial Black Holes Quantum Gravity Frank Krennrich, Iowa State University Colloquium, Iowa State University

  2. Outline • Primordial Black Holes: - Hawking Radiation - formation scenarios - observational limits - air Cerenkov burst technique - prospects with more glas • Quantum Gravity: - motivation - observational limits - prospects with large collection area Ground-based -ray Astronomy Towards the Future

  3. dM/dt ~ Lifetime t ~ M3 Hawking Radiation Temperature T: Lifetime t: Mass loss rate: X-ray emission: -) Shift in Peak Energy -) synchrotron cooling  depends on # of particle+resonance states available --> depends on particle physics S. W. Hawking, Nature, 248, 31 (1974) Ground-based -ray Astronomy Towards the Future

  4. dM/dt ~ Lifetime t ~ M3 Hawking Radiation Final burst: - STANDARD MODEL --> t ~ seconds --> Epeak ~ TeV - HAGEDORN MODEL --> t ~ 100 ns --> Epeak ~ 250 MeV THE HAGEDORN MODEL X-ray emission: -) Shift in Peak Energy -) synchrotron cooling R. Hagedorn, A&A, 5, 184 (1970) Porter & Weekes, MNRS, 183, 205 (1978) Ground-based -ray Astronomy Towards the Future

  5. PBH formation Gravit. collapse from local overdensity Particle horizon mass at formation epoch: --> bursts constrain ~ 10-23 s --> diffuse -ray background from 10-43 s …10-23 s density perturbations: - scale invariant fluctuations --> power law  phase transitions: - temporary softening of equation of state --> narrow mass range spectrum Ground-based -ray Astronomy Towards the Future

  6. Limits to PBHs present explosion rate (dn/dM ~ power law) -ray background: 30 MeV … 120 GeV Sreekumar et al., , ApJ, 494, 523 (1998) but clustering likely --> galactic halo anisotropy expected, see also Wright, ApJ, 459, 487 (1996) Antiprotons flux: - from PBHs - C.R. spallation Ground-based -ray Astronomy Towards the Future Krennrich et al. 2005, preliminary

  7. Microsecond burst detection technique Background reduction: • 0.1 – 100 s burst profile:  long Cerenkov pulse • Imaging:  characteristic shape  extremely smooth • No parallax:  VERITAS, large array Krennrich, Le Bohec & Weekes, ApJ, 529, 506 (2000) Ground-based -ray Astronomy Towards the Future

  8. Microsecond burst detection technique S.G.A.R.F.A.C.E. Short GAmma Ray Front Air Cherenkov Experiment Background reduction: • 0.1 – 100 s burst profile:  long Cerenkov pulse • Imaging:  characteristic shape  extremely smooth • No parallax:  VERITAS, large array TeV Electronics 379 379 Signal Splitter 55 FPGA-based trigger - reliable, tunable - 1,800 h data taken - use for future ACT FADCs & XILINX-FPGA 60 ns… 35s XILINX-FPGA based pattern trigger 55 Le Bohec, Krennrich & Sleege, Astropart. Phys., 23, 235 (2005) Ground-based -ray Astronomy Towards the Future

  9. Microsecond burst detection technique S.G.A.R.F.A.C.E. Short GAmma Ray Front Air Cherenkov Experiment Background reduction: • 0.1 – 100 s burst profile:  long Cerenkov pulse • Imaging:  characteristic shape  extremely smooth • No parallax:  VERITAS, large array TeV Electronics 379 379 Signal Splitter 55 FPGA-based trigger - reliable, tunable - 1,800 h data taken - use for future ACT FADCs & XILINX-FPGA 60 ns… 35s XILINX-FPGA based pattern trigger 55 Le Bohec, Krennrich & Sleege, Astropart. Phys., 23, 235 (2005) Ground-based -ray Astronomy Towards the Future

  10. Sensitivity to PBHs Ground-based -ray Astronomy Towards the Future

  11. Fluence Sensitivity to Bursts: 100 ns burst of 250 MeV -rays Min. photon density: ~ 0.1 ’s/m2 Ground-based -ray Astronomy Towards the Future

  12. SGARFACE III with more glas (ACT): • Fluence sensitivity S: - array trigger with all telescopes - probe scales 100 ns … 0.5 ms - 5 years, glas 70 m2 --> 5,000 m2 - FOV 5 degree ---> PBH~ 10-5 pc-3 y-1 • Probe microsecond burst phenomena: - counterparts to giant pulses from radio pulsars? - millisecond pulsars? - GRBs? Ground-based -ray Astronomy Towards the Future

  13. Quantum Gravity Effects I • Dispersion relation for photons Model dependent function effective QG energy scale • Vacuum as a quantum gravitational medium • vacuum responds differently to the propagation of • particles at different energies! • medium contains quantum fluctuations occuring on the • size scale of the Planck length: Ground-based -ray Astronomy Towards the Future

  14. Quantum Gravity Effects II • Dispersion relation for photons For small energies:  series expansion Sign ambiguity • Time delay between photons of different energy Ground-based -ray Astronomy Towards the Future

  15. Quantum Gravity Effects III • Time delay Most noticable: Amelino-Camelia et al, Nature, 393, 763 (1998) • Constraints from GRBs: GRB 930131 (Schaefer, PRL, 82, 4964, 1999) GRB 021206 (Boggs et al., astro-ph0310307)  EQG> 8.3 x 1016 GeV  EQG> 1.8 x 1017 GeV Ground-based -ray Astronomy Towards the Future

  16. Quantum Gravity Effects IV • Constraint from TeV blazars (Mrk 421 flare)  EQG> 4 x 1016 GeV Biller et al. 1999, Phys. Rev. Lett., 83, 2108 Gaidos et al. 1996, Nature, 383, 319 Ground-based -ray Astronomy Towards the Future

  17. Sensitivity beyond VERITAS 10s 1s 0.1s 10ms 1ms 0.1ms Ground-based -ray Astronomy Towards the Future

  18. Sensitivity beyond VERITAS 10s 1s 0.1s 10ms 1ms 0.1ms Ground-based -ray Astronomy Towards the Future

  19. Sensitivity beyond VERITAS 10s 1s 0.1s 10ms 1ms 0.1ms Ground-based -ray Astronomy Towards the Future

  20. Sensitivity beyond VERITAS 10s • Mrk 421, rate~10 Crab • 7 phot./s (VERITAS) • 70 phot./s (Beyond) • 100 ms possible @100 GeV • blazar variability time scale? 1s 0.1s 10ms 1ms 0.1ms Ground-based -ray Astronomy Towards the Future

  21. Sensitivity beyond VERITAS • H1426, rate~0.65 Crab • 0.4 phot./s (VERITAS) • 4 phot./s (Beyond) • few s possible @ 100 GeV 10s • Mrk 421, rate~10 Crab • 7 phot./s (VERITAS) • 70 phot./s (Beyond) • 100 ms possible @ 100 GeV 1s 0.1s 10ms 1ms 0.1ms Ground-based -ray Astronomy Towards the Future

  22. Sensitivity beyond VERITAS GRB021206: - 15 ms, but photon starved 10s 1s 0.1s 10ms 1ms 0.1ms Ground-based -ray Astronomy Towards the Future

  23. Sensitivity beyond VERITAS • GRB021206: • 15 ms, • but photon starved • GRB050904: • z=6.3 10s 1s 0.1s 10ms 1ms 0.1ms Ground-based -ray Astronomy Towards the Future

  24. Summary • PBHs: - particle astrophysics & Cosmology or U.L. ~ 10-5 pc-3 y-1 - ACT burst technique highly sensitive at 200 MeV @ ~ s • Quantum Gravity: - difficult to get much better (EQG > 1017 GeV) with blazar flares - need sources with sub-second variability at 100 GeV at z ~ 0.1 - GRBs at MeV energies photon starved for better constraints • Both topics discovery potential and we should consider them in design e.g., B. Carr: “PBHs are important for Cosmology, even if they do not exist” Ground-based -ray Astronomy Towards the Future

More Related