Galaxy Surveys

Durham has a long history of leading the exploitation of galaxy redshift surveys by confronting them with key theoretical predictions. It all started in the 1990's with the study of the large scale structure of the local Universe using the far-infrared selected galaxy redshift surveys QDOT and PSCz . We were major partners in the highly sucessful 2dF Galaxy Redshift Survey which, with its 240,000 galaxy redshifts, took the study of large scale structure into a new era. Our main contributions in the scientific exploitation of 2dFGRS included constraining the mass content of the Universe , measuring the present day density of stellar mass and the first detection of Baryon Acoustic Oscillations (BAOs). BAOs are now used as cosmic yardstick in setting geometrical constraints on the expansion history of the Universe, via surveys like BOSS, eBOSS, DESI, Euclid, ...

Currently we are involved in the following major surveys, which are either on-going or in the planning stages:

• DOE’s ambitious Dark Energy Spectroscopic Instrument (DESI) survey which will map the distribution of ~40 million galaxies over 14,000 square degrees out to redshift z=3.5 to probe the evolution of dark energy and set constraints of models of modified gravity. Durham is an institutional partner of DESI, with scientific interest in all DESI sub-surveys.
• ESO’s 4-metre Multi-Object Spectroscopic Telescope ( 4MOST) survey which design is especially intended to complement three key all-sky, space-based observatories of prime European interest: Gaia, Euclid, and eROSITA. Durham is an institutional partner of 4MOST, with scientific interest in many of 4MOST sub-surveys, including the Milky Way Halo Low Resolution Survey, the Galaxy Clusters Survey, the AGN Survey, the Galaxy Evolution Survey Waves and the Cosmology Redshift Survey.
• ESAs ambitious EUCLID survey which will map the distribution of galaxies over 15,000 square degrees out to redshift z=2 to probe the evolution of dark energy and set constraints of models of modified gravity, using spectroscopy and weak lensing.
• ESO’s 8-metre Multi-Object Optical and Near Infra-Red Spectrograph (MOONS) survey which will provide a new insight in the high-redshift universe (with about one million galaxy spectra at z>1) and detailed studies of millions of stars in the centre of our Milky-Way. Durham has access to the MOONS GTO time (~200 nights).
• The Physics of the Accelerating Universe Survey (PAUS) employs 40 narrow band filters to measure accurate photometric redshift for up to 2,000,000 galaxies to a depth of i~22.5. The two main goals with PAUS are to constrain galaxy evolution and intrinsic galaxy alignments.
• The 3/4 sky WALLABY HI survey with ASKAP radio telescope which is a forerunner of the Square Kilometer Array . This survey will yield a new view of the Universe by selecting galaxies based on their neutral (HI) gas content and by quantifying the rotation speed of this gas in each galaxy.