T. Stanev

BL Lac objects in the synchrotron proton blazar model

We calculate the spectral energy distribution (SED) of electromagnetic radiation and the spectrum of high-energy neutrinos from BL Lac objects in the context of the synchrotron proton blazar model. In this model, the high-energy hump of the SED is due to accelerated protons, while most of the low-energy hump is due to synchrotron radiation by co-accelerated electrons. To accelerate protons to sufficiently high energies to produce the high-energy hump, rather high magnetic fields are required. Assuming reasonable emission region volumes and Doppler factors, we then find that in low-frequency peaked BL Lacs (LBLs), which have higher luminosities than high-frequency peaked BL Lacs (HBLs), there is a significant contribution to the high-frequency hump of the SED from pion photoproduction and subsequent cascading, including synchrotron radiation by muons. In contrast, in HBLs we find that the high-frequency hump of the SED is dominated by proton synchrotron radiation. We are able to model the SED of typical LBLs and HBLs, and to model the famous 1997 flare of Markarian 501. We also calculate the expected neutrino output of typical BL Lac objects, and estimate the diffuse neutrino intensity due to all BL Lacs. Because pion photoproduction is inefficient in HBLs, as protons lose energy predominantly by synchrotron radiation, the contribution of LBLs dominates the diffuse neutrino intensity. We suggest that nearby LBLs may well be observable with future high-sensitivity TeV γ-ray telescopes.

Neutrinos from propagation of ultrahigh-energy protons

We present a calculation of the production of neutrinos during propagation of ultra-high energy cosmic rays from their astrophysical sources to us. Photoproduction interactions are modeled with the event generator SOPHIA that represents very well the experimentally measured particle production cross sections at accelerator energies. We give the fluxes expected from different assumptions on cosmic ray source distributions, cosmic ray injection spectra, cosmological evolution of the sources and different cosmologies, and compare them to the Waxman-Bahcall limit on source neutrinos. We estimate rates for detection of neutrino induced showers in a km3 water detector. The ratio of the local high energy neutrino flux to the ultra-high energy cosmic ray flux is a crucial parameter in distinguishing between astrophysical and cosmological (top-down) scenarios of the ultra-high energy cosmic ray origin.

Particle astrophysics with high energy neutrinos

Abstract The topic of this review is the particle astrophysics of high energy neutrinos. High energy is defined as E v > 100 MeV. Main topics include: (i) atmospheric neutrinos and muons from π, K and charm decay. They probe uncharted territory in neutrino oscillations and constitute both the background and calibration of high energy neutrino telescopes, (ii) sources of high energy neutrino beams: the galactic plane, the sun, X-ray binaries, supernova remnants and interactions of extra-galactic cosmic rays with background photons, (iii) an extensive review of the mechanisms by which active galaxies may produce high energy particle beams, (iv) high energy neutrino signatures of cold dark matter and, (v) a brief review of detection techniques (water and ice Cerenkov detectors, surface detectors, radio and acoustic detectors, horizontal airshower arrays) and the instruments under construction.The topic of this review is the particle astrophysics of high energy neutrinos. High energy is defined as

Monte Carlo simulations of photohadronic processes in astrophysics

E_{\nu}>100

Atmospheric neutrino flux above 1 GeV.

~MeV. Main topics include: -- atmospheric neutrinos and muons from

Three-dimensional calculation of atmospheric neutrinos

\pi

Cosmic ray interaction event generator SIBYLL 2.1

,

High energy cosmic rays

K

Ultra-high-energy Cosmic Rays and the Large-scale Structure of the Galactic Magnetic Field

and charm decay. They probe uncharted territory in neutrino oscillations and constitute both the background and calibration of high energy neutrino telescopes, -- sources of high energy neutrino beams: the galactic plane, the sun, X-ray binaries, supernova remnants and interactions of extra-galactic cosmic rays with background photons, -- an extensive review of the mechanisms by which active galaxies may produce high energy particle beams, -- high energy neutrino signatures of cold dark matter and, -- a brief review of detection techniques (water and ice Cherenkov detectors, surface detectors, radio- and acoustic detectors, horizontal airshower arrays) and the instruments under construction.

Gamma-Ray Production in Supernova Remnants

Abstract A new Monte Carlo program for photohadronic interactions of relativistic nucleons with an ambient photon radiation field is presented. The event generator is designed to fulfill typical astrophysical requirements, but can also be used for radiation and background studies at high energy colliders such as LEP2 and HERA, as well as for simulations of photon induced air showers. We consider the full photopion production cross section from the pion production threshold up to high energies. It includes resonance excitation and decay, direct single pion production and diffractive and non-diffractive multiparticle production. The cross section of each individual process is calculated by fitting experimental data, while the kinematics is determined by the underlying particle production process. We demonstrate that our model is capable of reproducing known accelerator data over a wide energy range.