COSMIC RAYS AND AGN's

Transcription

1 COSMIC RAYS AND AGN's RAZELE COSMICE ŞI NUCLEELE GALACTICE ACTIVE (don't worry, it is in Romanian) Sorin Roman

2 We'll try to talk about: -History -Composition -CR Spectrum -Detection -Reason why one should spend time with CR and AGN (tool for learning more Physics) -About what can happen if we have too many CR's or The AGASA higher flux

3 Victor Hess Victor Hess balloon observations of the ionization of air (up to 5350 m) Werner Kolhörster made ascensions up to 9300m Name of Cosmic Rays due to Millikan, 1925 First Institute for Cosmic Rays (Potsdam 1930, started by Kolhörster)

4 Pierre Auger Pierre Victor Auger (May 14, 1899 December 25, 1993) 1939 P.A. - discovered that the air showers can be used for detection of CRs 1963 John Linsley claimed he saw an event with energy > 1020 ev (Phys. Rev. '63)

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6 Cosmic Ray Composition - protons 90% - α particles 9% - heavy nuclei 1% -electrons, photons, antimatter

7 Cosmic Ray Spectrum

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10 Detection of Cosmic Rays Surface detectors: -scintillation detectors -water tanks (older technique) Difference between the arrival times was giving the orientation of the shower Ex: AGASA (Akeno Air Shower Extensive Array, Japan) -was used to show the anisotropies of Crs

11 Detection of Cosmic Rays Mirror Photomultiplier Fluorescence detectors - Excited Nitrogen molecules fluoresce in near UV with an emission line spectrum (approx 80% of the light is between nm.)

12 AUGER OBSERVATORY

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15 Dangers at the Auger Observatory site

16 Cosmic Rays, tools for learning Physics The UHECRs can not be of galactic origin: (Larmor radius) rl=1.08 E15 / ZBµG pc --- Z charge --- E15 particles energy in units of 1015 ev --- BµG is in microgauss

17 Cosmic Ray Sources GRB Objects below the diagonal line can not accelerate protons to 1020 ev All possible sources connected to AGN Now also GRB possible (A.M. Hillas 1984 ARA&A)

18 (M.Hillas 1984) GC-galactic cluster; RGL- radio galaxy lobes; RGH- radio galaxy hotspots; IGM- intergalactic medium; No losses due to interactions

19 Testing AGN models with cosmic Rays Model: All galaxies have a BH in the center which is starved for most of the time and that produces a relativistic jet (even if it is tiny) Idea : eg: I. Perez-Fournon, P. Biermann 1983; A&A130 Checked with real data: M81-H. Falcke 1996 ApJ-L467 Sgr.A&M31-H. Falcke, O. Heinrich,1994 A&A 292 Model to explain the jet disk symbiosis ( loud&quiet quasars): Falcke & Biermann 1995, A&A293

20 Description of the model (Falcke, Biermann 95) Ldisk= erg/sec AccrRatedisk/(Msun/year) Qjet/Ldisk=0.3 Ujet=UB+Uturb+Ue+p In equipartition in comoving frame Magnetic field energy density Turbulent kinetic plasma energy Energy of the relativistic particle

21 Testing the model (me) 1. optical luminosity of the galaxies ( local neighbourhood) 2. obtaining the statistical distribution of black holes (function of MBH)

22 3. determining the statistical activity level of the BH (Ledd-10-3Ledd Ledd ) 4. determining the time spent on each activity level (10-6% high, 10-4% medium, 99% low accretion rate) 5. losses - adiabatic (1+z) - due to the interaction with CMB (pair production, photo-pion production) The equation that will give the CR flux is: 6. check with the data (AGASA, HiRes, Monte Carlo simulations) (the flux obtained with the model fits the real data erg/cm2 s sr)

23 AGASA high flux -Might have statistical origins -If not than it needs another CR component (new physics )

24 Toys for older kids (motivated by AGASA high flux) - superheavy dark matter (X hadrons ) MX>1012GeV ; TX>1010 yrs; (no radically new physics, fits the data) - topological defects (good physics underneath, weak GZK cutoff, disfavored) - new particles (strongly interacting neutrino, light quasi stable hadrons Eg: glueballino ğg, NOT EXCLUDED ) - Lorentz Invariance Violation (Coleman & Glashow 1999) -GZK cutoff shifted Almost too good -stable neutrons to be true (Most radical proposal, FITS the data)

25 And if this still didn't convince you to study Cosmic Rays

26 AUGER Observatory can offer some other good motivations (thank you)