BPZ · Bayesian photometric red shifts: Public software and application to Cosmology
FP6 — Marie Curie Actions (Human Resources and Mobility)
- Duration
- 2005-09-01 → 2007-08-31
- EU contribution
- €80,000
- Participants
- 1
- Scheme
- IRG
Lines connect the coordinator with its partners.
Results in brief
Final Activity Report Summary - BPZ (Bayesian photometric redshifts: Public software and application to Cosmology)
This project has focused on improving the techniques that astronomers use to measure galaxy colours and redshifts. We have produced a catalogue of all the galaxies detected in the deepest observation carried out by the Hubble Space Telescope, the Ultra Deep Field, and designed and developed tools to analyse one of the most important astronomical surveys to be carried out from a telescope in continental Europe, ALHAMBRA-S, which is observing 4 square degrees of the sky (about 20 times the size of the full moon) with 23 filters. We expect ALHAMBRA to produce detailed colour and redshift information for more than half a million galaxies. In addition we have developed a new tool, called LensPerfect, to map the distribution of dark matter in galaxy clusters.
Data: CORDIS, © European Union
Project objective
Despite the spectacular technical progress of telescopes and spectrographs in the last years, it is unfeasible to systematically measure red shifts for galaxies fainter than I~24.5, a limit reached in the early 90' with the Keck telescope, and this situation is not expected to change in the foreseable future. On the other hand, deep observations with the Hubble Space Telescope and the best ground based telescopes routinely detect and measure the colours of thousands of galaxies fainter than the spectroscopic limit.This faint galaxy population hides the answer to many of the most important questions in observational cosmology, and the only method to extract red shift information from them is the so-called photometric red shift" technique, which models the expected colours of the galaxies as a function of red shift and compares them with the observations, reaching reasonable accuracy. Here I propose to improve and extend the bayesian approach described in Benitez 2000, implemented in the BPZ software package. This approach has proved itself to be one of the most reliable and precise, and BPZ has been adopted by large projects and surveys as the Advanced Camera for Survey pipeline, the Keck Team Survey and the GOODS survey at STScI.I plan to focus on two areas: the template library and the empirical red shift/type and red shift/size distributions used as priors by the bayesian approach. The result of this work will be a public software package, which based on previous experience with BPZ will be widely used by the European astronomical community.I will apply this software package to two major astronomical projects:a) the Advanced Camera for Surveys Lensing Cluster Survey. This program is observing 5 of the most massive galaxy clusters in the sky to depths close to the Hubble Deep Field and has already obtained unprecedented constraints on the shape of the cluster dark matter haloes.b) the ALHAMBRA Survey."
Original text from CORDIS.
Participants
- CONSEJO SUPERIOR DE INVESTIGACIONES CIENTIFICAS · MADRIDCoordinatorSpain
Links
Data: CORDIS, © European Union