1. C TA An advanced facility for ground-based high-energy gamma ray astronomy Why ? CTA

2. C TA An advanced facility for ground-based high-energy gamma ray astronomy Where do we aim ?

3. C TA An advanced facility for ground-based high-energy gamma ray astronomy The Cherenkov Telescope Array facility aims to explore the sky in the 10 GeV to 100 TeV energy range builds on demonstrated technologies combines guaranteed science with significant discovery potential is a cornerstone towards a multi-messenger exploration of the nonthermal universe

4. C TA An advanced facility for ground-based high-energy gamma ray astronomy Possible CTA sensitivity Crab 10% Crab 1% Crab GLAST MAGIC H.E.S.S. E. F(>E) [TeV/cm 2 s] AGN and pulsar physics Exploring the cutoff regime in Galactic sources A deep look at the TeV sky

5. C TA An advanced facility for ground-based high-energy gamma ray astronomy 4 x 4 degr. field SNR models using DAV 94 n = 1  = 0.1 (consistent with HESS plane scan) assuming 1 mCrab sensitivity

6. C TA An advanced facility for ground-based high-energy gamma ray astronomy How will we do it?

7. C TA An advanced facility for ground-based high-energy gamma ray astronomy Minimal detectable flux per band log 10 E=0.2, relative to a power-law Crab spectrum Sensitivity limit from event count, ~ 1/T. A limit from syst. error on background, indep. of T,A; ~1/ 2 limit from electron bg, ~ 1/T. A) 1/2 limit from proton bg, ~ 1/. T. A) 1/2 Threshold

8. C TA An advanced facility for ground-based high-energy gamma ray astronomy Background systematics Large fov helps Need stable instrument & electronics

9. C TA An advanced facility for ground-based high-energy gamma ray astronomy Ideal energy-dependent resolution & rejection

10. C TA An advanced facility for ground-based high-energy gamma ray astronomy Ideal energy-dependent resolution & rejection

11. C TA An advanced facility for ground-based high-energy gamma ray astronomy Possible CTA sensitivity Crab 10% Crab 1% Crab GLAST MAGIC H.E.S.S. E. F(>E) [TeV/cm 2 s] few 10 4 m 2 with dense coverage (5-10%) O(10 7 m 2 ) with low coverage (0.03-0.05%) few 10 5 m 2 with medium coverage (1-2%) ~3000 m 2 mirror area ~5000 m 2 mirror area ~4000 m 2 mirror area x 1.5

12. Not to scale ! Option: Mix of telescope types

13. C TA An advanced facility for ground-based high-energy gamma ray astronomy CTA as an observatory CTA will be a normal astrophysical observatory, open to the community, with professional operators, AOs, support for data analysis etc. Data will be public after some time (1 y?) Significant guaranteed time (~50%) for construction consortium CTA will most likely combine HEP and astrophysics worlds Observatory operation Significant contribution to construction by institute shops to reduce required investment

14. C TA An advanced facility for ground-based high-energy gamma ray astronomy Getting on (the European) track

15. C TA An advanced facility for ground-based high-energy gamma ray astronomy

16. Baseline given in ESFRI LoI

17. C TA An advanced facility for ground-based high-energy gamma ray astronomy

18. The EC/ESFRI route CAPACITIES Work programme – New research infrastructures Design studies (29 M€) Construction - Preparatory phase (63 M€) Infrastructure construction

19. Research Infrastructures in FP7 Robert-Jan Smits DG Research European Commission

20. Existing Infrastructures Design studies New Infrastructures Construction (preparatory phase; construction phase) FP7 Research Infrastructures in brief Integrating activities e-infrastructures ESFRI Roadmap Policy Development and Programme Implementation

21. Planning of calls and indicative budget Total operational budget 1630 M€ Call 1 2007 Call 2 2008 Call 3 2010 Call 4 2012 Integrating activities 275xx e-Infrastructures89115xx Design studies35x Construction – Support to the Preparatory Phase 135 x Construction – Support to the Implementation Phase RSFF (200 M€) + 100 M€ Policy Development and Programme Implementation 255xx Total per call (M€)284395

22. C TA An advanced facility for ground-based high-energy gamma ray astronomy World wide context CTA as European Initiative Close cooperation with Japan & US very desirable Joint technology development or Joint project could help to fund 2 nd site Near future: concentrate on FP7 / EC aspects

23. C TA An advanced facility for ground-based high-energy gamma ray astronomy Possible Schedule 0607080910111213 Site exploration Array layout Telescope design Component prototypes Array prototype Array construction Partial operation GLAST FP 7 Design Study “Letter of Intent” (100 pages, physics + conceptual design) Proposal Design Report Prep. Phase ? Products of Design Study

24. C TA An advanced facility for ground-based high-energy gamma ray astronomy Stages Letter of Intent (spring 07) Establishs physics case Discusses basic performance needs Lists possible sites and key characteristics Gives examples for array configurations Gives options for technical implementation Lists areas where further design is needed Proposal (summer/fall 08) Re-iterates physics case Gives detailed performances for (few) array layouts Gives details for (few) implementation options More on site options, organization options Gives cost estimates Design report (fall 09) Final Array layout Telescope implementation choices and details List of final few candidates sites {not clear if final site choice} Proposal for organization, governance, operation

25. C TA An advanced facility for ground-based high-energy gamma ray astronomy What should we have after design study Detailed knowledge of characteristics, availability of (few) good site candidates Array layout which optimizes physics performance for a given cost (and which is about 1 order of magnitude better than what we have now) Detailed design and (industrial) cost estimates for telescopes and associated equipment Plan how to organize, produce, install, commission, operate the facility; estimate for operating cost Model and prototype how to handle and analyze the data Small prototype series of components such as mirrors (~100), photosensors and electronics (~100-200 channels), probably a few drive systems, possible a secondary mirror, … to ensure that production issues and costs are understood

26. C TA An advanced facility for ground-based high-energy gamma ray astronomy Design study structures in Work Packages WP1Management of the design study WP2Astrophysics and astroparticle physics WP3Optimization of array layout, performance studies and analysis algorithms WP4Site selection and site infrastructure WP5Telescope optics and mirror WP6Telescope structure, drive, control WP7Photon detectors and focal plane WP8Readout electronics and trigger WP9Instrument calibration and analysis algorithms {merge with WP10?} WP10Atmospheric monitoring and associated science WP11Observatory operation and access (TOC + SOC) WP12Data handling, data processing, data management and data access (SDC) WP13Risk assessment and quality assurance, production planning (?) WP14Resource exploration

27. C TA An advanced facility for ground-based high-energy gamma ray astronomy The challenge - putting the puzzle together

28. C TA An advanced facility for ground-based high-energy gamma ray astronomy Grand Challenge I Find (and agree on) an array layout that has the required performance

29. C TA An advanced facility for ground-based high-energy gamma ray astronomy Camera field of view 3o3o 5o5o 8o8o Effective field of view for given camera diameter Large homogeneous fov minimizes systematics improves high-energy coverage Best for Galaxy: 7 o -9 o Best for AGN: small fov 5 o : Easy 7 o : Probably doable 10 o : Brick wall

30. C TA An advanced facility for ground-based high-energy gamma ray astronomy Quantity versus quality (versus R&D time) V. Vassiliev et al., astro-ph/0612718 40000 Pixels in camera for 10 o fov

31. C TA An advanced facility for ground-based high-energy gamma ray astronomy Grand Challenge II: Cost and Funding Crab 10% Crab 1% Crab GLAST MAGIC H.E.S.S. E. F(>E) [TeV/cm 2 s] few 10 4 m 2 with dense coverage (5-10%) O(10 7 m 2 ) with low coverage (0.03-0.05%) few 10 5 m 2 with medium coverage (1-2%) ~3000 m 2 mirror area ~5000 m 2 mirror area ~4000 m 2 mirror area x 1.5

32. C TA An advanced facility for ground-based high-energy gamma ray astronomy Grand Challenge II: Cost and Funding 12000 m 2 x 1.2 M€/100 m 2 = 144 M€ x 1.5

33. C TA An advanced facility for ground-based high-energy gamma ray astronomy Grand Challenge II: Cost and III: Reliability Reduce cost per area Can spent a lot on design, if savings in production cost result Exploit mass production to reduce cost Reliability Current telescopes (e.g. H.E.S.S.) have not reached the reliability required for such a large system Telescope (drives, end switches, …) Camera Software & control Design needs to be optimized for high reliability To limit operating and maintenance costs To maximize uptime To mimimize systematic errors

34. C TA An advanced facility for ground-based high-energy gamma ray astronomy Photon detectors Structure Optical layout and mirror facets Electronics weight fov Camera Mount & dish Telescope Array telescope types, size, fov telescope cost trigger options Site environmental conditions area, height Physics Grand Challenge IV: Coordination

35. C TA An advanced facility for ground-based high-energy gamma ray astronomy Grand Challenge V: Production C TA An advanced facility for ground-based high-energy gamma ray astronomy

36. Grand Challenge VI: Organization Legal form of the CTA observatory New (European?) entity ? Part of existing (European?) organization ? CERN ESO … Operated by existing national organization ? DESY Saclay Rutherford other National Labs Site decision will be influenced by Choice of host organization Contribution by host country or (transnational) host region

37. C TA An advanced facility for ground-based high-energy gamma ray astronomy What if … we don’t get the design study? continue CTA design little change in work programme, but missing funds will slow things down apply 2010 for Construction – Preparatory Phase we cannot reach the performance goals within reasonable costs? we cannot agree on a layout & technology? …