Astroparticle Physics

108 6 Primary Cosmic RaysFig. 6.30A neutrino-induced upward-goingmuon recorded in AMANDA. Thesize of the symbols is proportionalto the measured Cherenkov light{13}neutrino telescopescorresponding to 250 events per year. For large absorptionlengths of the produced Cherenkov light the effective collectionarea of the detector is even larger than the cross sectionof the instrumented volume. Assuming that there are abouthalf a dozen sources in our galaxy, the preceding estimatewould lead to a counting rate of about four events per day.In addition to this rate from point sources one would also expectto observe events from the diffuse neutrino backgroundwhich, however, carries little astrophysical information.Excellent candidates within our galaxy are the supernovaremnants of the Crab Nebula and Vela, the galactic center,and Cygnus X3. Extragalactic candidates could be representedby the Markarian galaxies Mrk 421 and Mrk 501,by M87, or by quasars (e.g., 3C273).Neutrino astronomy was pioneered with the Baikal telescopeinstalled in the lake Baikal in Siberia. The most advancedlarger telescopes are AMANDA and ANTARES 3 .AMANDA is taking data in Antarctica since several years,while the ANTARES detector which is installed in theMediterranean offshore Toulon started data taking early in2003. The NESTOR 4 detector has seen first results at theend of 2003. It is also operated in the Mediterranean offthe coast of Greece. Real neutrino astronomy, however, willrequire larger detectors like IceCube which is presently installedin Antarctica. It is expected that first results fromIceCube might become available from the year 2005 on.6.3 Gamma Astronomy“Let there be light.”The Bible; Genesis 1:36.3.1 IntroductionThe observation of stars in the optical spectral range belongsto the field of classical astronomy. Already the Chinese,Egyptians, and Greeks performed numerous systematic observationsand learned a lot about the motion of heavenlybodies. The optical range, however, covers only a minuterange of the total electromagnetic spectrum (Fig. 6.31).3 ANTARES – Abyssal Neutrino Telescope And Research Environmentof deep Sea4 NESTOR – Neutrino Extended Submarine Telescope withOceanographic Research