1. TeV-Gamma Ray Astrophysics with the H.E.S.S. Telescopes Thomas Lohse Humboldt University Berlin NordForsk Network Meeting in Astroparticle Physics Bergen, November 10, 2006

2. H.E.S.S.CANGAROO III MAGIC Veritas in construction Cherenkov Telescopes (3 rd Generation)

3. Cosmic ray origin and acceleration Supernova remnants Starburst galaxies Clusters of galaxies Unidentified galactic sources/surveys Astrophysics of compact objects AGNs Micro-Quasars & Stellar-mass black holes Pulsars Gamma ray bursts Cosmology Diffuse extragalactic radiation fields via cutoff in AGN spectra Astroparticle physics Neutralino annihilation in DM halos TeV  -Astronomy: The Physics Shopping List

4. H.E.S.S. H igh E nergy S tereoscopic S ystem MPI für Kernphysik, Heidelberg Humboldt-Universität zu Berlin Ruhr-Universität Bochum Universität Erlangen-Nürnberg Universität Hamburg Landessternwarte Heidelberg Universität Tübingen Ecole Polytechnique, Palaiseau APC, Paris Universite Paris VI-VII CEA Saclay CESR Toulouse GAM Montpellier LAOG Grenoble Paris Observatory LAPP Annecy Durham University Dublin Inst. for Advanced Studies NCAC Warsaw Astronomical Observatory Cracow Charles University Prag Yerewan Physics Institute North-West University, Potchefstroom University of Namibia, Windhoek

5. H.E.S.S. Site Clear sky Galactic centre culminates in zenith Mild climate Easy access Good local support (UNAM etc.) 23 o 16’ S, 16 o 30’ E, 1800 m asl Farm Göllschau, Khomas Hochland, 100 km from Windhoek

6. H.E.S.S. Phase I 4 telescopes operational since December 2003 Energy threshold (for spectroscopy): 100 GeV Single shower resolution: 0.1  Pointing accuracy: ≲ 20  Energy resolution:  20% June 2002September 2003February 2003December 2003

7. 960 pixel PMT camera Pixel size: 0.16° On-board electronics Weight: 900 kg 13m dish, mirror area 107 m 2 382 spherical mirrors, f =15m Point spread 0.03°-0.06°

8. 1.Particle Acceleration in Supernovae 2.The Galactic Centre 3.The Gamma Ray Horizon 4.Gamma Rays from a Super-Massive Black Hole 5.Gamma Rays from a Micro-Quasar Selected Results from H.E.S.S.

9. Supernovae

10. Synchrotron radiation Pulsar Wind Nebula: Electron wind from central pulsar heats the cloud The Standard Candle for TeV  -Astronomy Crab Supernova 1054 a.D. d = 2 kpc optical 1 lightyear But what about hadrons (protons and nuclei)?

11. Cassiopaeia A Supernova 1658 a.D. d = 2,8 kpc X ray picture “Shell Type” SNR: no electron wind from pulsar gamma signal from shell regions not totally drowned in that of electron wind good source class to observe hadron acceleration

12. resolution H.E.S.S. 2004 E   210 GeV RX J1713.7  3946 resolution H.E.S.S. 2004 E   210 GeV RX J1713.7  3946 First Resolved Supernova Shells in  -Rays H.E.S.S. 2005 E   500 GeV RX J0852.0  4622 Strong correlation with X-ray intensities SN-Shells are accelerating particles up to at least 200 TeV! But are these particles protons/nuclei or electrons?

13. E 2 dN/dE log(E) Stars radio infrared visible light X-rays VHE  -rays CMB Dust Cosmic Electron Accelerators BEeBEe Electron or Hadron Accelerator? Synchrotron Radiation Inverse Compton BB EeEe Cosmic Proton Accelerators Matter Density  0  Synchrotron Radiation of Secondary Electrons

14. EGRET   2.0 B  7, 9, 11  G Electron accelerator fits for RX J1713.7  3946 : Continuous electron injection over 1000 years Injection spectrum: power law with cutoff IC peak not well described B-field low for SNR shell large  & injection rate  bremsstrahlung important needs tuning at low E B  10  G   2.0, 2.25, 2.5 H.E.S.S.

15. Spatially resolved spectra of RX J1713.7  3946 TeV / X-ray intensities correlate, but NOT the spectral shapes  very hard to understand for pure electron accelerator ! TeV photon index  const H.E.S.S. preliminary G. Cassam-Chenaï A&A 427, 199 (2004) X-ray photon index

16.  Continuous proton injection over 1000 years  Injection spectrum: power law, index  2  Different cutoff shapes & diffusion parameters Proton accelerator fit: H.E.S.S. RX J1713.7  3946

17. Galactic Centre HESS J1837  069 HESS J1834  087 HESS J1825  137 HESS J1813  178 HESS J1804  216 G0.9  0.1 HESS J1747  281 Galactic Centre HESS J1745  290 HESS J1713  381 RX J1713.7  3946 HESS J1708  410 HESS J1702  420 HESS J1640  465 HESS J1634  472 HESS J1632  478 HESS J1616  508 HESS J1614  518

18.  no visible cut-off  rather large mass  measured flux  large cross-section and/or DM density Possible Interpretation: Dark Matter annihilation? 20 TeV Neutralino 20 TeV Kaluza Klein particle … unlikely ! H.E.S.S. MAGIC GC Crab

19. Galactic Centre Neighbourhood ~150 pc Galactic Centre HESS J1745  290 SNR G0.9  0.1 HESS J1747  281 EGRET GeV-  -sources

20. ...point sources subtracted  first resolved detection of diffuse TeV-  -radiation  cosmic rays (hadrons) interacting with molecular clouds ~150 pc Galactic Centre Neighbourhood molecular clouds density profiles HESS J1745  290

21. Cosmic Ray Spectrum at the GC... diffuse radiation expected flux for CR spectrum observed on earth Cosmic rays are much harder and have 3  larger density around the GC is very different from the one at earth Possible reason: Close-by source population Possibly single SN-explosion

22. The Gamma Ray Horizon

23. General Active Galactic Nuclei (AGN): Supermassive black holes, M  10 9 M  accretion disk and relativistic jets Blazar-Typ: Jet points towards the earth Doppler-boost  TeV  -radiation Blazars

24. E dN/dE Measurement of EBL (  Cosmology )  Physics of compact objects, acceleration/absorption in jets, … E dN/dE Absorption in (infrared) extragalactic background light (EBL)  (TeV) +  (EBL)  e + e - e+e+ e-e-  

25. Cut-off Energy and  -Ray Horizon PG 1553  113

26. H 2356 (x 0.1)  = 3.1±0.2 Preliminary EBL Unfolding of Measured Spectra 1 ES 1101  = 2.9±0.2 EBL H 2356 (x0.1)  = 3.1±0.2 Hardest plausible source spectrum  = 1.5 Hardest plausible source spectrum  = 1.5 Too much EBL

27. Lower Limits (Galaxy Counts) New Upper Bound on EBL Density Direct IRTS Measurements Assumed shape for rescaling H.E.S.S. upper bound from spectral shapes of 1ES 1101-232 (z = 0.186) H 2356-309 (z = 0.165) EBL density seems  2  smaller than expected! Little room for EBL sources other than galaxies (early stars…) Upper Limits excluded by H.E.S.S.

28. M87 Gamma Rays from the Rim of a Super-Massive Black Hole

29. M87 Radio Galaxy, Virgo Cluster, d  16 Mpc Central 3  10 9 M ⊙ Black Hole, R S  10 15 cm Relativistic Plasma Jet at 30   Blazar Radio VHE  -Rays host galaxy (optical) 99.9% c.l. extension upper limit Is there a better way to constrain the source size?

30. v   c  Yes, there sometimes is: Source variability!  source R time smearing: R/c source variability:  t* ≳ R/c shortest observable variability:  t ≳   R/c  upper limit on source size: R ≲  c  t relativistic Doppler factor reasonable: 1    50

31. Radio optical X-ray nucleus knots (jet) Doubling times of 2 days observed during 2005 high state of M87 Knots in jet are excluded as sources High energy particles created close to black hole horizon

32. Gamma Rays from a Micro-Quasar

33. LS 5039 Periastron   0 Apastron   0.5 observer inferior conjunction   0.716 superior conjunction   0.058  Massive star M   20 M ⊙  compact object: 1.5-5 M ⊙ neutron star or black hole?  Orbital Period 3.9 days  Eccentric orbit binary separation 2-4.5 R *

34. LS 5039 Periastron   0 Apastron   0.5 observer inferior conjunction   0.716 superior conjunction   0.058 Paredes et al. 2000  Faint X-ray emission slightly variable  Extended pc-scale radio emission possibly from jets (v  0,2 c)

35. VHE  -Ray Lightcurve folded with orbital period   0  0   0.5 observer   0.716   0.058 Modulation  absorption in radiation field  central emission (  1au) H.E.S.S.

36. VHE Spectral Modulation modulation strength strongly energy dependent not explainable by pure absorption effects complicated interplay between production & absorption mechanisms The central engine starts to reveal its physics

37. The Future: H.E.S.S. Phase II Large telescope under construction Improve sensitivity:  4 small  1 large  better than  8 small  Reduce threshold to O ( 20 GeV )

38. Summary Very successful initial years of H.E.S.S. Phase I Many new sources & several fundamental discoveries The VHE  -ray sky is well populated and complex Expect “bright” future