It’s a kind of MAGIC...
How to observe at very high energies...
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Current and future
instruments
Very High Energies
Imaging Atmospheric
Cherenkov Technique
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MWL-View
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Gamma Astronomy
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Facts about FACT
28.2.2011, Daniela Dorner, ISDC – Data Centre for Astrophysics
Current Cherenkov Telescopes
VERITAS
H.E.S.S.
MAGIC telescopes
CANGAROO III
28.2.2011, Daniela Dorner, ISDC – Data Centre for Astrophysics
Future Cherenkov Telescopes
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Discovery of many new sources in wider energy
range with improved sensitivity: CTA
Longterm monitoring of bright AGN:
FACT / DWARF
First G-APD Cherenkov Telescope
Cherenkov Telescope Array
Artist view: ASPERA / D.Rouable
Photo: Daniela Dorner
28.2.2011, Daniela Dorner, ISDC – Data Centre for Astrophysics
Major Atmospheric Gamma-ray Imaging Cherenkov Telescopes
Observatorio del Roque
de los Muchachos,
La Palma, 2200 m
MAGIC I:
Mirror: 17 m diameter
Observations during
moonlight
=> gain ~ 30% obs.time
Trigger threshold 50 GeV
special trigger: 25 GeV
MAGIC II:
'Clone' with technical
improvements
First light: 25.4.2009
now: stereo observations
Fast repositioning:
300 degrees in 30 sec
MAGIC
28.2.2011, Daniela Dorner, ISDC – Data Centre for Astrophysics
MAGIC
28.2.2011, Daniela Dorner, ISDC – Data Centre for Astrophysics
MAGIC
28.2.2011, Daniela Dorner, ISDC – Data Centre for Astrophysics
Gamma Rays
http://misclab.umeoce.maine.edu/boss/classes/SMS_491_2003/transparency.jpg
http://astrobob.areavoices.com/astrobob/images/thumbnail/Radio_spectrum_window21.jpg
Atmosphere is not transparent to gamma rays
=> indirect detection method from ground
28.2.2011, Daniela Dorner, ISDC – Data Centre for Astrophysics
Imaging Air Cherenkov Technique
Gamma
~ 10 km
Particle shower
28.2.2011, Daniela Dorner, ISDC – Data Centre for Astrophysics
Imaging Air Cherenkov Technique
~ 10 km
Particle shower
28.2.2011, Daniela Dorner, ISDC – Data Centre for Astrophysics
Imaging Air Cherenkov Technique
~ 10 km
Emission of
Cherenkov light
~ 1o
~ 120 m
28.2.2011, Daniela Dorner, ISDC – Data Centre for Astrophysics
Imaging Air Cherenkov Technique
1 Telescope => Mono Observations
~ 10 km
~ 1o
Image in the camera
~ 120 m
28.2.2011, Daniela Dorner, ISDC – Data Centre for Astrophysics
IACT Analysis Principle
28.2.2011, Daniela Dorner, ISDC – Data Centre for Astrophysics
Imaging Air Cherenkov Technique
Array of Telescope => Stereo Observations
28.2.2011, Daniela Dorner, ISDC – Data Centre for Astrophysics
Background Events
1 Gamma
1000 Background
28.2.2011, Daniela Dorner, ISDC – Data Centre for Astrophysics
Background Events
1 Gamma
1000 Background
Gamma
Candidates
28.2.2011, Daniela Dorner, ISDC – Data Centre for Astrophysics
Background Rejection
Parametrize shower image
28.2.2011, Daniela Dorner, ISDC – Data Centre for Astrophysics
Background Rejection
Cut in parameter distributions
28.2.2011, Daniela Dorner, ISDC – Data Centre for Astrophysics
Background Rejection
Cut in parameter distributions
28.2.2011, Daniela Dorner, ISDC – Data Centre for Astrophysics
Signal Reconstruction: Shower Origin
28.2.2011, Daniela Dorner, ISDC – Data Centre for Astrophysics
Signal Reconstruction: Shower Origin
Parametrize shower image
28.2.2011, Daniela Dorner, ISDC – Data Centre for Astrophysics
Signal Reconstruction: Shower Origin
Parametrize shower image
28.2.2011, Daniela Dorner, ISDC – Data Centre for Astrophysics
Signal Reconstruction: Shower Origin
28.2.2011, Daniela Dorner, ISDC – Data Centre for Astrophysics
Signal Reconstruction: Shower Origin
Skymap
28.2.2011, Daniela Dorner, ISDC – Data Centre for Astrophysics
Spectrum and Light Curve:
Energy Reconstruction
Problem: How to calibrate the detector in energy?
Atmosphere is part of the detector
28.2.2011, Daniela Dorner, ISDC – Data Centre for Astrophysics
Spectrum and Light Curve:
Energy Reconstruction
Gamma
Rays
Which energy?
Problem: How to calibrate the detector in energy?
Atmosphere is part of the detector
28.2.2011, Daniela Dorner, ISDC – Data Centre for Astrophysics
Spectrum and Light Curve:
Energy Reconstruction
Gamma
Rays
Problem: How to calibrate the detector in energy?
Atmosphere is part of the detector
We cannot bring CERN to space...
=> simulations are needed for energy reconstruction
28.2.2011, Daniela Dorner, ISDC – Data Centre for Astrophysics
Spectrum
Simulate processes in atmosphere
Simulate telescope
PG 1553+113: Spectrum MAGIC
Compare shower images
=> reconstruct energy
Albert et al. 2009
2009A&A...493..467A
28.2.2011, Daniela Dorner, ISDC – Data Centre for Astrophysics
Light Curve
PG 1553+113: 3 year light curve MAGIC
Dorner 2008
28.2.2011, Daniela Dorner, ISDC – Data Centre for Astrophysics
Light Curve
PG 1553+113: 5 year MWL light curve
Aleksić et al. 2010
28.2.2011, Daniela Dorner, ISDC – Data Centre for Astrophysics
MWL Spectrum:
Spectral Energy Distribution
Dorner 2008
PG 1553+113
Radio
IR/opt.
X-Ray
Gama-Ray
VHE
28.2.2011, Daniela Dorner, ISDC – Data Centre for Astrophysics
MWL Spectrum:
Spectral Energy Distribution
groundbased
Dorner 2008
Satellites
PG 1553+113
Radio
IR/opt.
X-Ray
Gama-Ray
VHE
28.2.2011, Daniela Dorner, ISDC – Data Centre for Astrophysics
MWL Spectrum:
Spectral Energy Distribution
Dorner 2008
PG 1553+113
Radio
IR/opt.
X-Ray
Gama-Ray
VHE
simultaneous
data July 2006:
MAGIC
HESS
Suzaku
KVA
+ historical data
28.2.2011, Daniela Dorner, ISDC – Data Centre for Astrophysics
The Multi-Wavelength Sky
MPIfR
408MHz
Mellinger
Optical
IUE
2-10keV
EGRET
HEAO-1
NRAO
1.42GHz
DIRBE
Ultraviolet
ROSAT
>100MeV TeV
Infrared
0.25-1.5keV
>100GeV
28.2.2011, Daniela Dorner, ISDC – Data Centre for Astrophysics
The Multi-Wavelength Sky
MPIfR
408MHz
Mellinger
Optical
IUE
2-10keV
Fermi
HEAO-1
NRAO
1.42GHz
DIRBE
Ultraviolet
ROSAT
NEW
TeV
Infrared
0.25-1.5keV
>100GeV
28.2.2011, Daniela Dorner, ISDC – Data Centre for Astrophysics
Gamma Astronomy
TeV Sky 2003
http://tevcat.uchicago.edu
28.2.2011, Daniela Dorner, ISDC – Data Centre for Astrophysics
Gamma Astronomy
TeV Sky 2003
28.2.2011, Daniela Dorner, ISDC – Data Centre for Astrophysics
Cherenkov Astronomy
TeV Sky 2003
http://tevcat.uchicago.edu
28.2.2011, Daniela Dorner, ISDC – Data Centre for Astrophysics
Cherenkov Astronomy
TeV Sky 2003
Discovery of plenty new
sources with the current
generation of Cherenkov
telescopes
TeV Sky 2011
http://tevcat.uchicago.edu
28.2.2011, Daniela Dorner, ISDC – Data Centre for Astrophysics
Future Cherenkov Telescopes
●
●
Discovery of many new sources in wider energy
range with improved sensitivity: CTA
Longterm monitoring of bright AGN:
FACT / DWARF
First G-APD Cherenkov Telescope
Cherenkov Telescope Array
Artist view: ASPERA / D.Rouable
Photo: Daniela Dorner
28.2.2011, Daniela Dorner, ISDC – Data Centre for Astrophysics
Photo: Thomas Bretz
Facts about FACT
First G-APD Cherenkov Telescope
28.2.2011, Daniela Dorner, ISDC – Data Centre for Astrophysics
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Location: 2200m, La Palma, MAGIC site
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Mount: old HEGRA CT3
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New drive system
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Refurbished Mirrors
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New Camera:
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Better reflectivity
Hexagonal, larger area (9.5 m²)
First Cherenkov camera using
G-APDs as photon detectors
Photo: Thomas Bretz
Facts about FACT
Robotic Operation
28.2.2011, Daniela Dorner, ISDC – Data Centre for Astrophysics
Prototype Camera: Results
H.Anderhub et al 2009 JINST 4 P10010
Prototype Astro-ph: http://arxiv.org/abs/0911.4920
camera
Mirror
Prototype:
First shower images successfully recorded
28.2.2011, Daniela Dorner, ISDC – Data Centre for Astrophysics
Facts about FACT: The Camera
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Photo sensors: G-APDs instead of PMTs
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1440 pixels (~0.11°/pixel), 4.5° FOV
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Solid light
cones
Square (2.8mm) to Hexagonal (9.5mm)
28.2.2011, Daniela Dorner, ISDC – Data Centre for Astrophysics
Facts about FACT: Timeline
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Installation of camera in La Palma: May 2011
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First Light => Proof of principle
Photo: Daniela Dorner
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Physics program: Monitoring of Bright AGN
28.2.2011, Daniela Dorner, ISDC – Data Centre for Astrophysics
Long term monitoring of AGN
DWARF Blazars
Mkn 501, Mkn 421, 1ES 1959+650, 1ES 2344+514,
H1426+428, PKS 2155-304
28.2.2011, Daniela Dorner, ISDC – Data Centre for Astrophysics
Outlook
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Dedicated Worldwide AGN Research Facility
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Network of small Cherenkov telescopes around the
globe
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24/7 monitoring
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Starting point:
collaboration with
Whipple 10 m
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AGN monitoring
28.2.2011, Daniela Dorner, ISDC – Data Centre for Astrophysics
Facts about FACT: Status
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Mount: old HEGRA CT3
=> still in La Palma
New drive system
=> installed
Refurbished Mirrors
=> installed and aligned
New Camera
Photo: Thomas Bretz
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=> currently being assembled at ETH Zürich
28.2.2011, Daniela Dorner, ISDC – Data Centre for Astrophysics
Facts about FACT: Collaboration
TU Dortmund
Uni Würzburg
EPF Lausanne
ETH Zürich
Uni Geneve (ISDC)
FACT
28.2.2011, Daniela Dorner, ISDC – Data Centre for Astrophysics