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Unveiling Geminga-like Gamstars: The Future of Neutrino Astronomy

Explore the tantalizing world of Gamstars, particularly Geminga, which hold the key to a new era in neutrino astronomy. Discover how these neutron stars emit gamma rays and neutrinos, and how groundbreaking discoveries by Fermi and Ice Cube are revolutionizing our understanding of the cosmos.

margaret-emerson
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Unveiling Geminga-like Gamstars: The Future of Neutrino Astronomy

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  1. Neutrinos from Gamstars G.F. Bignami, IUSS Pavia M. Roncadelli, INFN Pavia

  2. GAMSTAR? = Gamma-Ray (Neutron) Star! Why now ? 1- Geminga-like Gamstars can bridge gap e.m.astronomy  n astronomy

  3. ’00s

  4. GAMSTAR? = Gamma-Ray (Neutron) Star! Why now ? 1- Geminga-like Gamstars can bridge gap e.m.astronomy  n astronomy 2- Fermi Discovers tens of new Gemingas

  5. LAT discovers a radio-quiet pulsar! P ~ 317 ms Pdot ~ 3.6E-13 Characteristic age ~ 10,000 yrs

  6. The Pulsing Sky Pulses at 1/10th true rate

  7. GAMSTAR? = Gamma-Ray (Neutron) Star! Why now ? 1- Geminga-like Gamstars can bridge gap e.m.astronomy  n astronomy 2- Fermi Discovers tens of new Gemingas 3- Ice Cube 40 is now coming of age

  8. Starting point: ns via p photoproduction p + g n + p+  n + ap+ + b (p+ + p-) •  m + n  e + nenm N.B. pion photoproduction kinematically possible if Ep Eg > 0.3 GeV2 f f= 1/1-cosqgp

  9. Geminga à la Goldreich and Julian Max proton energy = 0.4 103 TeV (P=0.237 s) Proton number density n= 3.2 1011 cm-3 High-energy photons are produced through curvature radiation by e+, e- close to light cylinder RL = c/W = 1.1 109 cm Average photon energy assumes Eg =200 MeV

  10. Simple geometry tranform cylinder in spherical shell 0.9RL < r < RL The GJ energetic protons, accelerated close to the star, interact with gs aroundRL Production of energetic neutrinos is boosted well above that on thermal target photons !

  11. The target energetic photon density ng is ng = 0.7 10 7 cm-3 Introducing a standard cross section s p + g n + p+ = 5 10-28 cm-2 The resulting conversion probability P P= s 0.1 RL ng or 3.9 10-13

  12. Thus, the resulting Geminga neutrino flux in Ice Cube above 1 TeV for its measured distance is 1-10 km-2 y-1 magic # 4 ICE3 ! Bonus #1 : contrary to our rough approximation, neutrinos will be pulsed, just like gamma-rays

  13. Bonus #2 : Geminga will be the first and the brightest , but a list of Gamstar as candidate neutrino sources will soon be provided by Fermi 3000 271 100 25 3 1 1 1 Think of the number of neutrino sources 50 ys from now!

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