360 likes | 373 Views
The Cherenkov Telescope Array aims to explore the sky in the 10 GeV to 100 TeV energy range, blending guaranteed science with significant discovery potential. It is vital for multi-messenger exploration of the nonthermal universe.
E N D
CTA Why ?
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
Possible CTA sensitivity GLAST Crab E.F(>E) [TeV/cm2s] 10% Crab MAGIC AGN and pulsar physics H.E.S.S. Exploring the cutoff regime in Galactic sources 1% Crab A deep look at the TeV sky
4 x 4 degr. field SNR models using DAV 94 n = 1 e = 0.1 (consistent with HESS plane scan) assuming 1 mCrab sensitivity
Sensitivity Threshold limit from event count, ~ 1/T.A Minimal detectable flux per band Dlog10E=0.2, relative to a power-law Crab spectrum limit from proton bg, ~ 1/q (h.T.A)1/2 limit from syst. error on background, indep. of T,A; ~1/q2 limit from electron bg, ~ 1/q (T.A)1/2
x 1.5 ~3000 m2 mirror area ~4000 m2 mirror area ~5000 m2 mirror area Possible CTA sensitivity GLAST Crab E.F(>E) [TeV/cm2s] 10% Crab MAGIC few 104 m2 with dense coverage (5-10%) H.E.S.S. O(107 m2) with low coverage (0.03-0.05%) 1% Crab few 105 m2 with medium coverage (1-2%)
Option: Mix of telescope types Not to scale !
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
The EC/ESFRI route CAPACITIES Work programme – New research infrastructures • Design studies (29 M€) • Construction - Preparatory phase (63 M€) • Infrastructure construction
Research Infrastructures in FP7 Robert-Jan Smits DG Research European Commission
FP7 Research Infrastructures in brief Existing Infrastructures New Infrastructures Design studies Integrating activities ESFRIRoadmap Construction (preparatory phase; construction phase) e-infrastructures Policy Development and Programme Implementation
World wide context CTA as European Initiative • Close cooperation with Japan & US very desirable • Joint technology development or • Joint project • could help to fund 2nd site • Near future: concentrate on FP7 / EC aspects
Possible Schedule FP 7 Design Study Prep. Phase ? GLAST “Letter of Intent” (100 pages, physics + conceptual design) Proposal Design Report Products of Design Study
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
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
Grand Challenge I • Find (and agree on) an array layout that has the required performance
Camera field of view Effective field of view for given camera diameter 3o 5o 8o 5o: Easy 7o: Probably doable 10o: Brick wall Best for Galaxy: 7o-9o Best for AGN: small fov • Large homogeneous fov • minimizes systematics • improves high-energy coverage
Quantity versus quality (versus R&D time) V. Vassiliev et al., astro-ph/0612718 40000 Pixels in camera for 10o fov
x 1.5 ~3000 m2 mirror area ~4000 m2 mirror area ~5000 m2 mirror area Grand Challenge II: Cost and Funding GLAST Crab E.F(>E) [TeV/cm2s] 10% Crab MAGIC few 104 m2 with dense coverage (5-10%) H.E.S.S. O(107 m2) with low coverage (0.03-0.05%) 1% Crab few 105 m2 with medium coverage (1-2%)
2000 1500 2 1000 Cost per 100 m 500 0 0 200 400 600 800 1.000 1.200 2 Mirror area (m ) Grand Challenge II: Cost and Funding 12000 m2 x 1.2 M€/100 m2 = 144 M€ x 1.5
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
Grand Challenge IV: Coordination Physics Array Site area, height telescope types, size, fov telescope cost trigger options environmental conditions Telescope Optical layout and mirror facets Photon detectors weight fov Electronics Structure Camera Mount & dish
Grand Challenge V: Production CTA An advanced facility for ground-based high-energy gamma ray astronomy
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
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? • …