Elisabete de Gouveia Dal Pino (IAG-USP, Brazil) On behalf of the CTA Collaboration FAPESP Workshop March, 2015 Thanks to W. Hoffmann, B. Rudak, E.Moulin, A. Zech, D. Mazim, J. Hinton, D. Torres Unveiling the Gamma Ray Universe
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Elisabete de Gouveia Dal Pino (IAG-USP, Brazil)
On behalf of the CTA Collaboration
FAPESP Workshop
March, 2015
Thanks to W. Hoffmann, B. Rudak, E.Moulin, A. Zech, D. Mazim, J. Hinton, D. Torres
Unveiling the Gamma Ray
Universe
tevcat.uchicago.edu/
Supernovae
Pulsar wind neb.
Stellar clusters,…
Binary systems
Unidentified
AGN
Starburst-Gal.
TeV sky today (144 sources, 49 extragalactic)
po gg
p± m
±n
p + nucleus p +X
Image accelerators with gamma rays
Spectraand flux reflect
those of acc. particles
SEEING COSMIC ACCELERATORS
e+, e- :
IC, SSC -> g-ray photons
Detecting very high energy gamma rays:Cherenkov telescopes
Cherenkov Image
Cherenkov “light pool”on the ground:area ~105 m2
dormant nowH.E.S.S.
50 GeV to ∼ 50 TeV, collecting area ∼ 105m2,
∼ 4º FoV, angular res. ~ 0.1º
(TeV)
Key design goals: 10-fold increased sensitivity at TeV energies 10-fold increased effective energy coverage Larger field of view for surveys Improved angular resolution Full sky coverage: and array in each
hemisphere
CTA: What one can (hopefully) afford
Energies down to 20 GeV Cosmology++
Rapid Slewing20 seconds
transients
Energy Resolution≈10% lines,
features
Sensitivity & Collection
Area×10 all topics
Field of View≈8° surveys,
extended objects
Angular Resolution
Few arcminute morphology
Energies up to 300 TeV Pevatrons
REQUIREMENTS & DRIVERS
Core-energy array:23 x 12 m tel. (MST)Davies-Cotton reflector
- FOV: 7-8 degreesmCrab sensitivityin the 100 GeV–10 TeVdomain
Low-energy section:4 x 23 m tel. (LST)- Parabolic reflector- FOV: 4-5 degreesenergy thresholdof some 10 GeV High-energy section:
70 x 5-6 m tel. (SST)Davies-Cotton reflector(or Schwarzschild-Couder)- FOV: ~10 degrees10 km2 area at multi-TeV energies
(one) possible configurationSouthern 100 M€ Array (2006 costs)
Sensitivity (in units of Crab flux)for detection in each 0.2-decade energy band
LST
MST
SST
background andsystematics limited
background limited
rate (=area) limited
dark matterSignatures of EBL,
IGMF, LIV
ANGULAR
RESOLUTION
CTA SCIENCE CASE
Theme 1: Cosmic Particle Acceleration How and where are particles accelerated?
How do they propagate?
What is their impact on the environment?
Theme 2: Probing Extreme Environments Processes close to neutron stars and black holes?
Processes in relativistic jets, winds and explosions?
Exploring cosmic voids
Theme 3: Physics Frontiers – beyond the SM What is the nature of Dark Matter? How is it distributed?
Is the speed of light a constant for high energy photons?
Do axion-like particles exist?
EBL and IGMF…
EXAMPLE: GALACTIC PLANE SURVEY
H.E.S.S.
CTA, for same exposure
expect ~1000 detected sources
CTA
Current GalacticVHE sources (with distance estimates)
HESS
CTA
REACH
CTA VERSUS FERMI – TRANSIENT
SOURCES
Hinton & Funk
DARK MATTER ANNIHILATION
Canonical
cross section
Complex, structured VHE source (BH)
Gas clouds illuminated by Pevatron?
Dark matter halo emission?
Launch of Fermi bubbles?
GALACTIC CENTER REGION
5 sigma contours
CTA TELESCOPES
23 m diameter
389 m2 dish area
28 m focal length
1.5 m mirror facets
4.5o field of view
0.1o pixels
Camera ∅ over 2 m
Carbon-fibre structure
for 20 s positioning
Active mirror control
4 LSTs on South site
4 LSTs on North site
Prototype = 1st telescope
LARGE
TELESCOPE
(LST)
LST FULL PROTOTYPE
Will be constructed on La
Palma, starting in 2015
Elevation
drive
prototype
Dish structure
prototype
MEDIUM-SIZED 12 M TELESCOPEOPTIMIZED FOR THE 100 GEV TO ~10 TEV RANGE
100 m2 dish area
16 m focal length
1.2 m mirror facets
8o field of view
~2000 x 0.18o pixels
25 MSTs on South site
15 MSTs on North site
Berlin
MST prototype
operational
PHOTOMULTIPLIER CAMERAS
Recording signal waveform for “interesting” (triggered) images
Options:
Capacitor pipeline + analog trigger + (identical) “drawers”
NectarCam (Pixel cluster prototypes operational)
LSTCam (Pixel cluster prototypes operational)
Flash-ADC + digital trigger + rack-based electronics
Flashcam (144 pixel prototype operational)
SST - OPTIMIZED FOR THE RANGE ABOVE 10 TEV
SINGLE MIRROR SSTPROTOTYPE INAUGURATION JUNE 2
DUAL-MIRROR TELESCOPES
Vassiliev, Fegan, Brousseau
Astropart.Phys.28:10-27,2007
Reduced plate scale
Reduced psf
Uniform psf across f.o.v.
➜ Cost-effective small
telescopes with compact
sensors (SST-2M)
➜ Higher-performance
telescopes with small pixels
(SCT)
SST - OPTIMIZED FOR THE RANGE ABOVE 10 TEV
DUAL MIRROR ASTRI SSTPROTOTYPE INAUGURATION SEPTEMBER 24
ASTRI PROTOTYPE INAUGURATION
September 24th, 2014
Sierra la Nave Obs., Catania
ASTRI-CTA SST-2M PROTOTYPE
ASTRI CAMERA
The ASTRI Mini-Array: CTA precursor
The goal is the deployment and operation
of the mini-array with 9 SST-2M
telescopes at the CTA south site
Italy
Brasil
South
Africa
BRAZILIAN FUNDING FOR ASTRI-
CTA-MINI-ARRAY
Fundacao de Amparo `a Pesquisa do Estado de Sao Paulo
1.5 MEuro for building 3 SST-2M telescopes of the Mini-Array
IAG-USP
University of Sao Paulo
Sao Carlos
Sao Paulo
Rio de Janeiro
Universidade de Sao Paulo
Instituto de Astronomia, Geofisica e Ciencias Atmosfericas
Universidade Federal do Rio
Centro Brasileiro Pesquisas FisicasVitor de Souza
Carlos Todeiro Peixoto
Gustavo Rojas (UFSCar)
Ivone Albuquerque (IFUSP)
Ulisses Barres de Almeida
Ronald Cintra Shellard
Edivaldo M. Santos
Joao Torres MelloInstituto de Fisica de Sao Carlos
Elisabete de Gouveia Dal Pino
Rodrigo Nemmen
Grzegorz Koval
Claudio Melioli
Reinaldo Santos-Lima
Chandra Singh
Renato Gimenes (Eng.)
Carlos Firmino (Eng.)
Made in
Brazil
CTA Mini-Array
MST support
LST support
Argentina, Armenia, Austria, Brazil, Bulgaria, Czech Republic, Croatia, Finland,
France, Germany, Greece, India, Italy, Ireland, Japan, Namibia, Netherlands,
Norway, Poland, Slovenia, Spain, South Africa, Sweden, Switzerland, UK, USA
CTA MEMBERS: 28 COUNTRIES>800 SCIENTISTS AND ENGINEERS FROM >100
INSTITUTIONS
SITE CANDIDATES
+30
-30
Warning: map not quite accurate
two sites to cover full sky
at 20o-30o N, S
Critical
Design
Review
Site
Decision(s)
Design generic site
infrastructure
Design site-
specific
infrastructure
Implement site infrastructure
Site characterisationDetailed site
char., surveys
Continued monitoring of environmental and
atmospheric conditions
Telescope design
and prototyping
Produce Pre-Production
telescopes
Deploy and operate
Pre-Production telescopes
Final design
mods.
Mass-produce and deploy
telescopes
2015 2016 2017
Production
Readiness
Reviews
2018
Founding Decision
Pre-Production
Readiness Reviews
CTA SCIENCE
In-depth understanding
of known objects and
their mechanisms
Expected discoveries
of new object classes
The fun part:
Things we haven’t thought of ?
PHOTON PROPAGATION: AXION LIMITS
Axion conversion ??
De Angelis et al.arXiv:0707.2695,0707.4312
Sanchez-Conde et al.,arXiv:0905.3270
M. Meyer et al.arXiv:1302.1208
Increased transparency of Universe Modulation of spectra
In neV Axion mass range comparable toor better than dedicated experiments
Pg➝g
e.g. H.E.S.S. arXiv:1311.3148
PHOTON PROPAGATION: LI VIOLATION
g
HESS, arXiv:1101.3650arXiv:0810.3475
Velocity dispersion across TeV energy rangeless than ~20 s for ~109 yr travel ⋍ 10-15
➜ LIV mass scale > 2.1018 GeV (~E), 6.1010 GeV (~E2)
EarthAGN
A DIFFERENT BEAST:
OBSERVATORY
CTAObservatory
CTA Observatory users
CTA Consortium
Observation
proposals
Data
Key Science Projects
Data from Key Science Projects
“Gamma ray astronomy traces the energy skeleton of the Universe”
How do cosmic particle accelerators work?
Do do particles propagate?
Do do particles influence their cosmic environment?
ASTRI DUAL MIRROR CONCEPT
FROM CURRENT ARRAYS TO CTA
light pool radius
R ≈100-150 m
≈ typical telescope spacing
Sweet spot for
best triggering
and reconstruction:
most showers miss it!
large detection area
more images per shower
lower trigger threshold
SPECTRA OF SUPERNOVA REMNANTS
( from S. Funk)
No Pevatron yet! Cas A
(SN IIb)
RX J1713.7
(SN II/Ib ?)
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