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2012October 15
Brunetto Ziosi
Physics and Astronomy Department,University of Padua
JC
better physical information from images
mock/real images comparisons with less bias
Mock imagesvs SAMs
Templates for
Low z
Ellipticals
Sbc
Irregulars
Dropouts candidateregion
More scattered, difficult to distinguish:- redshift- mass- dust- star formation history- SFR
High z dropouts
LIGHTCONE
MOCK IMGs
Comparison between the:- lightcone galaxies- mock images galaxies- real images galaxies
"Observing" the lightcone the differences decrease
SDSS like survey: observing the same cluster
@z~0.02
@z~0.09
@z~0.21
Mock massive cluster @z=0.4
Real HST/ACS of C10024 @z=0.4
Mock cluster from different directions
Spherical
Spherical
Filamentary
Projection effects matter
- constant sky background- convolution with PSF- rebinning to get the correct pixels scale- dark current- Poisson noise- Gaussian readout noise- WCS astrometry- .fits images with optionally noise corresponding to noise maps
- Generate mock images of the entire fields based on the model of the HST/WFC3- Fast and useful for surveys not yet performed
Match pixel-to-pixelnoise variations andgeometry of the real datausing weight maps(inverse variance of each pixel during image reduction)
Reproduce each individual tile
Dark Matter particles
FOF
(Sub-)haloes
Merger Trees
Semi-AnaliticMethodsGalaxies
Light-cone
Synth images
SExtractorCatalogues
IGMabsorption
PSF, Noise,Background
WMAP1 cosmology extendable to,for example, WMAP7 (Angulo&White 2010)
L-GALAXIESorGALFORM
- Galaxies at discrete snapshotsrearranged to mimic the distance-cosmic time relation
- Real vs observed volume dependon distance: box replication
Taking care of the orientation
- mimic the particular telescope (exposure, gain, ...)
with 3 models:- Meikisin (2006)- Inoue & Iwata (2008)- Madau (2005)
- Ideal combination of volume and resolution- Semi Analitic Models- DB infrastructure
- Millennium Run Observatory- "a theoretical virtual observatory which uses virtual telescopes to 'observe' semi-analytic galaxy formation simulations"- produce syntetic data that can be analyzed like data from observation
indirect comparison
Galaxy formation and evolution
observations
models, simulations
Specialization andtechnical sofistication
incompleteness, contamination, cosmic variance, limited resolution, noise, ...
physical quantities
CANDELS example
Felix Baumgartner:Maximum altitude of 39.045 kilometresMaximum speed of 1,342.8 km/h (=Mach 1.24)Total free fall time of 4 minutes 20 secondsTotal free fall distance of 36,529 metres
Colours and structure
Dropout galaxies
Galaxy clusters f(z)
4-So?
Galaxy #
3-How?
2-The idea!
1-The problem...
5-Conclusions
Millennium Run because:
z~4
z~5
z~6
That's all Folks!