The PAU Project

The PAU (Physics of the Accelerating Universe) Survey studies the existence and properties of dark energy from the observations of Red-shift Space Distortions (RSD) and Weak Lensing Magnification (MAG) from galaxy cross-correlations as main cosmological probes.

The PAU Team has built an instrument, PAUCam, designed to be located at the prime focus of the 4-m diameter William Herschel Telescope (WHT) in La Palma. The simulations indicate that PAUCam at the WHT will be able to image about 2 square degrees per night in 40 narrow-band filters plus five wide-band filters to an AB magnitude depth of i~23, which means to provide low-resolution (R~50) photometric spectra for around 30000 galaxies, 5000 stars and 1000 quasars. PAUCam saw its first light on june 3rd, 2015, and finished the second commissioning phase on november 18th, 2015.

The PAU Survey will image an area of 100/200 square degrees with 40 narrow band filters. Our simulations show that it is possible to obtain a redshift precision above 0.0035 (1+z) for 70% of the imaged galaxies. With these observations it would be possible to obtain competitive measurements of the dark-energy equation of state parameters, comparable to other much larger spectroscopic and photometric surveys now taking place or planned for the near future.

CIEMAT participation in PAU

The CIEMAT Group is a key part for the technical development and building of the PAU camera. We are responsible of many subsystems of the instrument. We contribute to the electronics with several developments. We are responsible of the design, validation, production and maintenance of the preamplification and clock electronic boards, we have developed a test station for CCD characterization and validation and perform the validation of the camera filter system.

We also contribute to the mechanical engineering, with the design, building and validation of the tool for installing the camera at the telescope and the mechanical design and cooling of the crates for the electronic boards.

The CIEMAT group also develops software for the instrument, mainly related to the data quality control.

From the science viewpoint, we contribute in the data analysis for weak lensing magnification and redshift space distortions.