The 2-degree Field Lensing Survey

Breaking news, July 2017: our joint cosmological analysis of lensing and large-scale structure statistics has been submitted to MNRAS!

Cone plot of 2dFLenS galaxy redshifts (image credit: Sam Hinton).

2dFLenS is a galaxy redshift survey performed at the Australian Astronomical Observatory to extend the spectroscopic-redshift coverage of deep-imaging gravitational lensing surveys in the southern sky, in particular the Kilo-Degree Survey. The current 2dFLenS-KiDS overlap is illustrated in the following plot.

Overlapping imaging and spectroscopic surveys: dark squares are KiDS-450 pointings, and the fluctuating background is the gridded number density of 2dFLenS (blue) and BOSS (red) galaxies. The solid rectangles outline the footprint of the full KiDS survey (image credit: Chris Blake).

The science goals of 2dFLenS are to perform new tests of gravitational physics, and to promote the development of algorithms for the joint analysis of imaging and spectroscopic data including galaxy-galaxy lensing, redshift-space distortion and photometric-redshift calibration.

The 2dFLenS sample consists of 70,079 redshifts, including 40,531 Luminous Red Galaxies spanning redshift range z < 0.9, and 28,269 redshifts which form a magnitude-limited nearly-complete sub-sample in the magnitude range 17 < r < 19.5. Further key statistics are collected in the table below. For more details, please refer to the 2dFLenS survey paper (Blake et al. 2016, MNRAS, 462, 4240).

Total number of redshifts 70,079
Survey area 731 sq deg, mostly in KiDS-South
Redshift range z < 0.9
AAT nights used 53 (63% clear)
Survey duration 17/9/14 - 5/1/16 (14B, 15A, 15B semesters)
AAT fields observed 275, 45-min integrations

Chris Blake, cblake@swin.edu.au