Why ?

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

Why ?

CTA


Where do we aim ?


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


10-14

10-13

10-12

10-11

10 100 1000 104 105

E x

F(>

E)

[TeV

/cm

2s]

E [GeV]

Possible CTA sensitivity

Crab

10% Crab

1% Crab

GLAST

MAGIC

H.E.S.S.

E.F(>E) [TeV/cm2s]

AGN and pulsar

physics Exploring the cutoff regime in Galactic sourcesA deep look

at the TeV sky


4 x 4 degr. field

SNR modelsusing DAV 94n = 1 = 0.1

(consistent with HESSplane scan)

assuming1 mCrabsensitivity


How will we do it?


Minimal detectable flux per band log10E=0.2, relative to a power-lawCrab spectrum

Sensitivity

limit fromevent count,~ 1/T.A

limit fromsyst. erroron background,indep. of T,A;~1/2

limit fromelectron bg,~ 1/T.A)1/2

limit fromproton bg,~ 1/.T.A)1/2

Threshold


Ideal energy-dependent resolution & rejection


10-14

10-13

10-12

10-11

10 100 1000 104 105

E x

F(>

E)

[TeV

/cm

2s]

E [GeV]

Possible CTA sensitivity

Crab

10% Crab

1% Crab

GLAST

MAGIC

H.E.S.S.

E.F(>E) [TeV/cm2s]

few 104 m2 with dense

coverage (5-10%)

O(107 m2) with low coverage

(0.03-0.05%)few 105 m2 with medium

coverage (1-2%)

~3000 m2 mirror area



x 1.5

Not to scale !

Option:Mix of telescope types


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 worldsObservatory operationSignificant contribution to construction by institute shops to reduce required investment


Getting on (the European) track


Baseline given in ESFRI LoI


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

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

Planning of calls and indicative budget

Total operational budget 1630 M€

Call 12007

Call 22008

Call 32010

Call 42012

Integrating activities 275 x x

e-Infrastructures 89 115 x x

Design studies 35 x

Construction – Support to the Preparatory Phase

135 x

Construction – Support to the Implementation Phase

RSFF (200 M€) + 100 M€

Policy Development and Programme Implementation

25 5 x x

Total per call (M€) 284 395


World wide context

CTA as EuropeanInitiative

Close cooperation with Japan & US very desirableJoint technology development orJoint project

could help to fund 2nd site

Near future: concentrate on FP7 / EC aspects


Possible Schedule

06 07 08 09 10 11 12 13

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 DesignReport

Prep. Phase ?

Products ofDesign Study


Stages

Letter of Intent (spring 07)Establishs physics caseDiscusses basic performance needsLists possible sites and key characteristicsGives examples for array configurationsGives options for technical implementation Lists areas where further design is needed

Proposal (summer/fall 08)Re-iterates physics caseGives detailed performances for (few) array layoutsGives details for (few) implementation optionsMore on site options, organization optionsGives cost estimates

Design report (fall 09)Final Array layoutTelescope implementation choices and detailsList 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 candidatesArray 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 equipmentPlan how to organize, produce, install, commission, operate the facility; estimate for operating costModel and prototype how to handle and analyze the dataSmall 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


Design study structures in Work Packages

WP1 Management of the design study

WP2 Astrophysics and astroparticle physics

WP3 Optimization of array layout, performance studies and analysis algorithms

WP4 Site selection and site infrastructure

WP5 Telescope optics and mirror

WP6 Telescope structure, drive, control

WP7 Photon detectors and focal plane

WP8 Readout electronics and trigger

WP9 Instrument calibration and analysis algorithms {merge with WP10?}

WP10 Atmospheric monitoring and associated science

WP11 Observatory operation and access (TOC + SOC)

WP12 Data handling, data processing, data management and data access (SDC)

WP13 Risk assessment and quality assurance, production planning (?)

WP14 Resource exploration


The challenge- putting the puzzle together


Grand Challenge I

Find (and agree on) an array layout that has the required performance


Camera field of view

3o 5o 8o

Effective field of viewfor given camera diameter

Large homogeneous fov • minimizes systematics• improves high-energy coverage

Best for Galaxy: 7o-9o

Best for AGN: small fov

5o: Easy7o: Probably doable10o: Brick wall


Quantity versus quality (versus R&D time)

V. Vassiliev et al., astro-ph/0612718

40000 Pixels in camera for 10o fov


10-14

10-13

10-12

10-11

10 100 1000 104 105

E x

F(>

E)

[TeV

/cm

2s]

E [GeV]

Grand Challenge II: Cost and Funding

Crab

10% Crab

1% Crab

GLAST

MAGIC

H.E.S.S.

E.F(>E) [TeV/cm2s]

few 104 m2 with dense

coverage (5-10%)

O(107 m2) with low coverage

(0.03-0.05%)few 105 m2 with medium

coverage (1-2%)




x 1.5


Grand Challenge II: Cost and Funding

0

500

1000

1500

2000

0 200 400 600 800 1.000 1.200

Cos

t pe

r 10

0 m

2

Mirror area (m2)

12000 m2 x 1.2 M€/100 m2 = 144 M€ x 1.5


Grand Challenge II: Cost and III: Reliability

Reduce cost per areaCan spent a lot on design, if savings in production cost resultExploit mass production to reduce cost

ReliabilityCurrent telescopes (e.g. H.E.S.S.) have not reached the reliability required for such a large system

Telescope (drives, end switches, …)CameraSoftware & control

Design needs to be optimized for high reliabilityTo limit operating and maintenance costsTo maximize uptimeTo mimimize systematic errors


Photon detectors

Structure

Optical layout andmirror facets

Electronics

weightfov

Camera Mount & dish

Telescope

Array

telescope types, size, fovtelescope costtrigger options

Site

environmentalconditions

area,height

Physics

Grand Challenge IV: Coordination


Grand Challenge V: ProductionC TA An advanced facility for ground-based high-energy gamma ray astronomy


Grand Challenge VI: Organization

Legal form of the CTA observatoryNew (European?) entity ? Part of existing (European?) organization ?

CERNESO…

Operated by existing national organization ?DESYSaclayRutherfordother National Labs

Site decision will be influenced byChoice of host organizationContribution by host country or (transnational) host region


What if …

we don’t get the design study?continue CTA designlittle change in work programme, but missing funds will slow things downapply 2010 for Construction – Preparatory Phase

we cannot reach the performance goals within reasonable costs?we cannot agree on a layout & technology?

…

Why ?

Documents

Transcript of Why ?