1. Dieter Horns – University of Tübingen 28-31 August 2006, Madison Wisconsin HESS: Status and future plans Dieter Horns (Univ. Tübingen) on behalf of German Hermann (MPI-K, Heidelberg) for the HESS collaboration http://www.mpi-hd.mpg.de/hess

2. Dieter Horns – University of Tübingen 28-31 August 2006, Madison Wisconsin Status of German Hermann? ● View from his hotel room in Walvis Bay, Namibia ● He passes his greetings

3. Dieter Horns – University of Tübingen 28-31 August 2006, Madison Wisconsin Update on the collaboration ● Durham University ● Dublin Institute for Advanced Studies ● Nicolaus Copernicus Astronomical Center, Warsaw ● Jagiellonian University, Cracow ● Polish Academy of Sciences, Warsaw ● Charles University, Prague ● Yerevan Physics Institute ● University of Namibia, Windhoek ● North West University, Potchefstroom ● MPI-K, Heidelberg ● Humboldt Universität Berlin ● Ruhr-Universität Bochum ● Universität Hamburg ● Landessternwarte Heidelberg ● Universität Tübingen ● Ecole Polytechnique, Palaiseau ● Universités Paris VI-VII ● APC Paris ● CEA Saclay ● Obsérvatoire Paris Meudon ● LAPP Annécy ● Université Grenoble ● Université Montpellier ● CERS Toulouse >100 Scientists from 24 institutes from 9 countries 5 institutes have joined recently for HESS Phase II

4. Dieter Horns – University of Tübingen 28-31 August 2006, Madison Wisconsin Control building Security fence ROTSE 3c robotical optical telescope Weather/atmospheric monitoring 120 m Camera shelter HESS I telescope A tour of the site would also include: Guest houses, generator building, and lots of wild animals!

5. Dieter Horns – University of Tübingen 28-31 August 2006, Madison Wisconsin Recent changes: ROTSE 3c has been moved, ATOM telescope installed ● ATOM (Automatic Telescope for Optical Monitoring) – LSW Heidelberg, PI S. Wagner – 75 cm Alt-Az – Multi-filter Photometry – Automated operation implementation in progress – “Slave” operation with HESS ● ROTSE (Robotic Optical Transient Search Experiment), PI Carl Akerlof – 45 cm, unfiltered fast telescope – Robotic operation – Monitoring of ~100 Blazars

6. Dieter Horns – University of Tübingen 28-31 August 2006, Madison Wisconsin HESS Phase I telescopes ● Single telescope: July 2002 ● Full four telescopes: December 2003 20 t steel frame, f=15 m Alt-Azimuth mount,100°/min <10” pointing uncertainty 380 front aluminised glass mirror tiles=107 m 2 mirror surface Camera shelter ● 960 PMT with Winston cones arranged in 60 drawers ● Sector based topological trigger (3>5.3 p.e. within 1.3 ns gate) ● 5° degree fov (1.4 m) ● Signals read out via multiplexed dual channel analogue ring storage 1 Ghz (integrated in camera) ● Total weight 900 kg ● Multiple (>1) telescope, ~300Hz coincidence required for system event read-out References: Telescope & opticalsystem Bernlöhr et al. (2003), Cornils et al. (2003) Camera: Vincent et al. (2003), System trigger: Funk et al. (2004)

7. Dieter Horns – University of Tübingen 28-31 August 2006, Madison Wisconsin Operational statistics ● Data taking started in July 2002, no shut-down ● Shifts with a crew of three: Total of ≈300 flights from Europe to Namibia >2 Mio km of travelling ● Total data taken (until July 2006)=3623 hrs (≈900 hrs/yr) ● Total amount of data stored: 18.7 Tbyte ● Distribution centers: MPI-K Heidelberg, Data center in Lyon

8. Dieter Horns – University of Tübingen 28-31 August 2006, Madison Wisconsin Processing of data ● Calibration: Pedestals, broken pixels, relative and absolute gain calibration (see Aharonian et al. 2004) ● Two independent calibration and analyses chains (with different flavors), for a comparison see astro-ph/0607247: – “Hillas”-type analyses – Model based analyses

9. Dieter Horns – University of Tübingen 28-31 August 2006, Madison Wisconsin Performance (“Hillas” type analyses) ● Point-spread function: r 68 =0.08° per event ● Energy resolution: ΔE/E≈15% ● Point source sensitivity: 5σ detection 1% Crab: 25 hours 5% Crab: 5 hours 10% Crab: 20 min 50% Crab: 1.5 min 100% Crab: 0.5 min astro-ph/0607333, A&A in press Remember: HEGRA ->100 hrs for 5% Crab

10. Dieter Horns – University of Tübingen 28-31 August 2006, Madison Wisconsin Energy threshold ● Energy threshold as expected from simulations

11. Dieter Horns – University of Tübingen 28-31 August 2006, Madison Wisconsin Highlight results ● Blind survey of the Galactic plane: New and so far unidentified sources, Science 307, 1938 (2004) ● Discovery of gamma-rays from an XRB system Science 309, 746, 2005 ● Low level of O/NIR EBL Nature 440, 1018 (2006) ● Gamma-rays from the Galactic Ridge Nature 439 695 (2006) ● Gamma-ray image from RXJ1713 Nature 432, 75 (2004) See also the following talks by Berrie Giebels (Extragalactic observations) and DH (Galactic sources)

12. Dieter Horns – University of Tübingen 28-31 August 2006, Madison Wisconsin HESS Phase II ● Aims: – Extending the energy threshold to ~10-20 GeV – Achieve overlap in energy (and time) with GLAST – Improving the sensitivity at 100 GeV ● Approach: – Increase mirror size to 600 m 2 (equiv. 28 m ⊘, 560 t steel frame) – Increase focal length to 36 m – Decrease pixel size to 0.07° (fov=3.17°, >2t camera) – Use well-established HESS Phase I type electronics – Combine a single telescope with the 4 Phase I telescopes

13. Dieter Horns – University of Tübingen 28-31 August 2006, Madison Wisconsin Artist's impression ^

14. Dieter Horns – University of Tübingen 28-31 August 2006, Madison Wisconsin Structure in more details: Mirror dish ● Structure designed by MAN ● Parabolic dish (time dispersion) ● Adjustable Hexagonal mirror tiles ● Achieve similar optical performance as HESS Phase I CTs

15. Dieter Horns – University of Tübingen 28-31 August 2006, Madison Wisconsin Camera design & electronics ● Diameter of 2.5 m ● 2048 pixels in 128 drawers ● 99 overlapping sectors (64 pixels each) ● 2.5-3 t weight ● Focussing (10 cm shift) ● Read-out with “SAM”: Swift Analogue memory at 1 GHz (improved version of the ARS) ● Level 1 trigger at 3 kHz

16. Dieter Horns – University of Tübingen 28-31 August 2006, Madison Wisconsin Expected performance of HESS Phase II Punch et al. (2006) Based upon simulations verified with HESS Phase I

17. Dieter Horns – University of Tübingen 28-31 August 2006, Madison Wisconsin Physics with HESS Phase II ● Study gamma-ray emission from pulsar magnetosphere ● Gamma-ray emission from XRBs ● Explore the high redshift universe: AGNs, Radio-Galaxies, GRBs ● Indirect Dark matter search

18. Dieter Horns – University of Tübingen 28-31 August 2006, Madison Wisconsin Status of HESS Phase II ● Steel construction has started, finished by spring 2007 ● Installation of camera end of 2007/2008 ● Phase II operational well within the beginning of the GLAST (second half of 2008)

19. Dieter Horns – University of Tübingen 28-31 August 2006, Madison Wisconsin News from German: Steel construction, Aug 2006

20. Dieter Horns – University of Tübingen 28-31 August 2006, Madison Wisconsin Backup

21. Dieter Horns – University of Tübingen 28-31 August 2006, Madison Wisconsin