The VHE gamma-ray sky viewed with H.E.S.S. Werner Hofmann MPI für Kernphysik Heidelberg © Philippe Plailly HESS = High Energy Stereoscopic System

H.E.S.S Imaging - induced air showers Threshold ~ 100 GeV Sensitivity ~ 1% Crab in 25 h © Philippe Plailly

Gamma- ray ~ 10 km Particle shower Detection of TeV gamma rays using Cherenkov telescopes ~ 1 o Cherenkov light ~ 120 m Key issue: huge detection area ~ 10 5 m 2

(from Sky & Telescope) M Air showers look a bit like meteors

5 decades in frequency missing! Thermal Emission

 o    ±   ±  p + nucleus   +X  Cosmic particle accelerators imaged using (secondary) gamma rays  Origin of Cosmic Rays ?

Supernova remnants Pulsar wind nebulae Binaries “Dark sources” Galactic center & DM (?) A tour of galactic particle accelerators:

Supernova remnants Pulsar wind nebulae Binaries “Dark sources” Galactic center & DM (?)

alias Vela Junior Supernova remnant shells

RXJ Particle acceleration to beyond 100 TeV Index ~ 2.0 Cutoff or break at ~20 TeV Index constant across SNR E -2

Man-made accelerators No. of particles Energy How could cosmic accelerators work?

Man-made accelerators No. of particles Energy Nature’s accelerators No. of particles Energy Enrico Fermi How could cosmic accelerators work?

Energy gain / cycle  E/E ~  shock... many 100 cycles to reach TeV energies …... takes several 100 years Generates power law spectrum dN/dE ~ E -(2+  ) … at some point, particle falls behind shock … Peak energy ~10 15 eV … depending on size of shock front … typical E p  10 E  Nonlinear process with efficiency ~50%! … accelerated particles generate plasma waves … Nature’s accelerators How could cosmic accelerators work? No. of particles Energy

Puzzling: X-ray –  -ray correlation Suzaku: Y. Uchiyama, T. Takahashi Texas Symp HESS gamma rays Suzaku X-rays Contour lines: ASCA X-rays Y. Uchiyama et al H.E.S.S.

The Vela region Vela (Rosat) Vela Junior d ≈200 pc age ≈ 700 y

Gamma ray sources & their physics A tour of galactic particle accelerators: Supernova remnants Pulsar wind nebulae Binaries “Dark sources” Galactic center & DM (?) Cosmology with gamma rays

Gamma ray sources & their physics A tour of galactic particle accelerators: Supernova remnants Pulsar wind nebulae Binaries “Dark sources” Galactic center & DM (?) Cosmology with gamma rays G in X-rays Chandra / H.Matheson & S.Safi-Harb Supernova shell PWN

Vela-X ROSAT contours Chandra Peak energy output at ~10 TeV

Pulsar wind nebulae -ray sources are extended O(10 pc) displaced from pulsar

Morphology of gamma-ray sources: HESS J > 2.5 TeV 1 – 1.5 TeV < 1 TeV > 2.5 TeV 1 – 2.5 TeV < 1 TeV > 2.5 TeV 1 – 2.5 TeV < 1 TeV

Gamma ray sources & their physics A tour of galactic particle accelerators: Supernova remnants Pulsar wind nebulae Binaries “Dark sources” Galactic center & DM (?) Cosmology with gamma rays

Gamma ray sources & their physics Microquasar LS (?) M  object in eccentric day orbit around M  star closest approach ~10 12 cm or ~2 stellar radii Gamma-ray period: 3.908±0.002 days

Spectral variation unique chance to “experiment” with a cosmic source by varying conditions Modulation due to absorption by   e + e -

Gamma ray sources & their physics A tour of galactic particle accelerators: Supernova remnants Pulsar wind nebulae Binaries “Dark sources” Galactic center & DM (?) Cosmology with gamma rays

“Dark” sources: Objects which only shine in gamma rays ! … without plausible counterparts in X-rays, radio, …

Not all remain dark: HESS J promoted from unidentified source to SNR / PWN White et al Brogan et al cm VLA Ubertini et al., 2005 Integral HESS J Radio Supernova shell D.J. Helfand et al., astro-ph/ C.L. Brogan et al., astro-ph/ TeV size S. Funk et al., astro-ph/ XMM

HESS sensitivity Explanations … Old supernova remnants (Yamazaki et al., astro- ph/ ) Old PWN GBR remnants (Atoyan et al., astro-ph/ ) Basic idea: electrons are gone in old objects Stellar winds / OB assoc. DM halo objects

A tour of galactic particle accelerators: Supernova remnants Pulsar wind nebulae Binaries “Dark sources” Galactic center & DM (?) Cosmology with gamma rays

Rainer Schödel

The center of our Galaxy Galactic plane Sgr A East SNR (radio) Sgr A* HESS error circle H.E.S.S.

The center of our Galaxy Galactic plane H.E.S.S.

Point sources subtracted The center of our Galaxy Galactic plane H.E.S.S. p  “Diffuse” -rays tracing molecular clouds

Origin of the GC gamma rays ? Top-down: Annihilation of dark matter particles   qq, gg Generates characteristic density profile: sharp spike with long tail and characteristic energy spectrum ~ quark fragmentation + some  decays

Is it DM?  Angular distribution PRL, in press H.E.S.S. PSF NFW Dark Matter

Is it DM?  Angular distribution PRL, in press Diffuse emission subtracted H.E.S.S. PSF

Is it DM?  Spectrum Preliminary 20 TeV Neutralino 20 TeV KK particle proposed before H.E.S.S. data proposed after early H.E.S.S. data

Extragalactic TeV astronomy Physics of AGN jets Cosmology: Density of cosmological extragalactic background light (EBL) Quantum gravity & exotics

1 minute bins 15 x Crab flux PKS MJD Variability time scale ~ 3 min R s /c ~ 150…300 min (1…2 x 10 9 M  )

 Fast variability … and quantum gravity

© Lynette Cook