"een nieuwe blik op sterrenkunde" "panoramische camera's en het astro-wise...
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"Een nieuwe blik op sterrenkunde"
"Panoramische camera's en het Astro-Wise systeem"
Gijs Verdoes Kleijn
Kapteyn Astronomical Institute, University of Groningen
Human vision: data load
• Eye: – resolution ~5/60deg– Field of view 90^2deg– 2x2 pixel sampling per resolution element – Pixels: 2160^2– Dynamic range: 1e3-1e5: 2^16– One image ~9Mbyte– One image/sec for 70years: 18Pbyte– Costs 18Pbyte (0.33euro/Gbyte)~ 6million euro
Brain does something smart…….
Astronomical vision: data load
• Camera on telescope: – Resolution through atmosphere ~1/3600deg (atmospheric
blurring)– Whole sky: 41e3 deg^2– 2x2 pixel sampling per resolution– Pixels: ~(1.5e6)^2 – Dynamic range: 2^16– One image full sky: 4Tbyte– One full sky/sec for 70years: 8.4e6 Pbyte (was 18Pbyte for eye)– Further data increasing ’ factors: HST 1/10 of atmospheric
resolution; time-resolution; wavelength resolution– Data decreasing factor: depending on depth of exposure: lots of
dark area
Something smart to deal with large datasets is crucial!
The history of the Universe
The big questions (according to me)• Dark matter/energy: (In what form/Where) is ~90% of the
matter? What is dark energy?• Structure formation: how do objects exactly form?
Structure
Galaxy ClustersGalaxies
Black holesStars
Planetary systems
Cooling
Expansion
+Gravity
Collapse
Astronomical science which uses large-area imaging
because it is• Needle in the hay-stack objects• Subtle effects requiring large number statistics
Galaxy clusters PlanetsSupernovaQuasars & Gamma Ray Bursts
AsteroidsLensing
The OmegaCAM panoramic camera
• 16k x 16k mosaic of 32 CCDS: – Each CCD 2k x4k
• Field of view: 1deg^2• pixel size 0.21 arcsec / 15μm. • 330 to 1000 nm • Starting operations end 2006
USM
Padova
1deg
1deg
HST
VLT Survey Telescope (VST) at Paranal, Chile
Artist’s impression
Very Large Telescope (VLT) VLT Survey Telescope (VST)
OmegaCAM vision: data load
Vast amount of data• Single image 550 Mbyte (~200 screens
for full resolution) • Sole instrument: OmegaCAM
observes equivalent of Southern sky in ~3 years (30 min exp, 300 nights/year)
• Many filters & science programs• Of order 10 Tbyte of raw
data/year with time-varying atmosphere, instrument & telescope performance
Vast amount of data• Single image 550 Mbyte (~200 screens
for full resolution) • Sole instrument: OmegaCAM
observes equivalent of Southern sky in ~3 years (30 min exp, 300 nights/year)
• Many filters & science programs• Of order 10 Tbyte of raw
data/year with time-varying atmosphere, instrument & telescope performance
Panoramic image processing and analysis: the classical way
• Image cleaning of instrumental effects– examples: varying pixel sensitivities; cosmic
rays; image distorsions; correction for extinction of light (in atmosphere and
instrument)•
• Derivation of astronomical parameters– examples: size galaxy, color star, brightness
supernova
• Analysis of results– Comparison to theory; statistics
• Image cleaning of instrumental effects– examples: varying pixel sensitivities; cosmic
rays; image distorsions; correction for extinction of light (in atmosphere and
instrument)•
• Derivation of astronomical parameters– examples: size galaxy, color star, brightness
supernova
• Analysis of results– Comparison to theory; statistics
Panoramic image processing and analysis: the Astro-Wise way
• Image cleaning of instrumental effects– examples: varying pixel sensitivities; cosmic
rays; image distorsions; correction for extinction of light (in atmosphere and
instrument)
• Derivation of astronomical parameters– examples: size galaxy, color star, brightness
supernova
• Analysis of results– Comparison to theory; use statistics
• Image cleaning of instrumental effects– examples: varying pixel sensitivities; cosmic
rays; image distorsions; correction for extinction of light (in atmosphere and
instrument)
• Derivation of astronomical parameters– examples: size galaxy, color star, brightness
supernova
• Analysis of results– Comparison to theory; use statistics
Databas
e
The architecture of the Astro-Wise system
Parallel Computing
DatabaseAll OmegaCam
images
Astro-Wise is on-line: you can use it whenever there is internet
www.astro-wise.org/portal
An test-case of Astro-Wise system use
Asteroids
10000
Ecliptic~plane in which planets move
Observations
Asteroids on images• Cross-correlating >3e5 known asteroids with
images:– Code: PyEphem+Astro-Wise – (~1day on Linux box)
• Analysis is student project
To take advantage of state-of-the-art technology to better understand how the Universe came about and evolved you need a team of :
1deg
1deg
HST
-experts
-experts
-experts
-experts
To take advantage of state-of-the-art technology to better understand how the Universe came about and evolved you need a team of :
1deg
1deg
HST
-experts
-experts
OmegaCEN at the Kapteyn Astronomical InstituteOmegaCEN director: professor Edwin Valentijn
Contacts for more info:
• Astro-Wise, OmegaCEN– Gijs Verdoes Kleijn
• Astronomy at RUG in general:– Student advisor: Leon Koopmans– Education advisor: Greta de Vries
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