Lorentz Workshop - June 2016
Leiden Observatory
e.g. CANDELS UDS: Galametz et al. (2013)
Brammer et al. (2008)
Arnouts et al. (1999)
Ilbert et al. (2006)
Bender et al. (2001)
Bolzonella et al. (2000)
Feldmann et al. (2006)
Benitez (2000)
Total citations: ~2800
Additional rest-frame errors
Corrections to the observed zeropoints
Brammer et al. (2008)
Dust
AGB Stars?
PAH/Dust emission/AGN?
Brammer et al. (2008)
Benitez (2000)
(aka machine learning)
Euclid: ~1.5 billion galaxies
LSST: ~10 billion galaxies
Estimated time to run EAZY on all sources (on a desktop machine):
~2+ years (Euclid)
~14+ years (LSST)
Sanchez et al. (2014)
Weak Lensing requirements:
Scatter
Bias
i.e. a representative subset of your sample with spectroscopic redshifts
Neural Networks
Self-organizing Maps (SOMs)
Deep learning
Support Vector Machines (SVM)
Naive Bayes
Gaussian Processes
Generalized Linear Models
Bayesian Network
k-Nearest Neighbour
Boosted Decision Trees
Randomised Forests
Relevance vector machines
Radial basis function networks
Normalised inner product nearest neighbour
Directional neighbourhood fitting
Voronoi tesselation density estimator
Non-conditional density estimation
Dahlen et al. (2012)
7/11 submitted photo-z estimates significantly overconfident for 1-sigma errors
Wittman et al. (2016)
See also Bordoloi et al. (2010)
Dahlen et al. (2012)
= Median of all photo-z estimates
= Median of best 5 photo-z estimates
See also Carraso Kind & Brunner (2014)
Also works for diff. templates with the same code
Masters et al. (2015)
Masters et al. (2015)
Targeted spectroscopic follow-up of unexplored colour space (Underway): spectra
Ongoing spectroscopic surveys:
(e.g. VANDELS/VUDS/LEGA-C/OzDES/HETDEX) spectra
New massively multiplexed spectroscopic surveys -
Subaru/PFS and WHT/WEAVE in the North: spectra
VLT/MOONS and VISTA/4MOST in the South: spectra
e.g. 'fuzzy archetypes' method of Speagle & Eisenstein (2015)
If speed is the requirement:
Scope for new template codes which make use of...
- Efficient parallelisation
- GPU acceleration
If physical interpretation of fitted SEDs is the requirement:
Fit using SED modelling codes, e.g.:
- Prospector
- BEAGLE
- MAGPHYS/Cigale
New Euclid team code?
* Carrasco Kind and Brunner (2014)
Bayesian model combination/averaging (BMC/BMA)*
Spectroscopic sample (Bootes)
QSO Templates
Stellar Templates
ML estimates