Harrison, I;
Brown, ML;
Tunbridge, B;
Thomas, DB;
Hillier, T;
Thomson, AP;
Whittaker, L;
... Watson, RA; + view all
(2020)
SuperCLASS - III. Weak lensing from radio and optical observations in Data Release 1.
Monthly Notices of the Royal Astronomical Society
, 495
(2)
pp. 1737-1759.
10.1093/mnras/staa696.
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Abstract
We describe the first results on weak gravitational lensing from the SuperCLASS survey: the first survey specifically designed to measure the weak lensing effect in radio-wavelength data, both alone and in cross-correlation with optical data. We analyse 1.53deg2 of optical data from the Subaru telescope and 0.26deg2 of radio data from the e-MERLIN and VLA telescopes (the DR1 data set). Using standard methodologies on the optical data only we make a significant (10σ) detection of the weak lensing signal (a shear power spectrum) due to the massive supercluster of galaxies in the targeted region. For the radio data we develop a new method to measure the shapes of galaxies from the interferometric data, and we construct a simulation pipeline to validate this method. We then apply this analysis to our radio observations, treating the e-MERLIN and VLA data independently. We achieve source densities of 0.5 arcmin−2 in the VLA data and 0.06 arcmin−2 in the e-MERLIN data, numbers which prove too small to allow a detection of a weak lensing signal in either the radio data alone or in cross-correlation with the optical data. Finally, we show preliminary results from a visibility-plane combination of the data from e-MERLIN and VLA which will be used for the forthcoming full SuperCLASS data release. This approach to data combination is expected to enhance both the number density of weak lensing sources available, and the fidelity with which their shapes can be measured.
| Type: | Article |
|---|---|
| Title: | SuperCLASS - III. Weak lensing from radio and optical observations in Data Release 1 |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1093/mnras/staa696 |
| Publisher version: | https://doi.org/10.1093/mnras/staa696 |
| Language: | English |
| Additional information: | This version is the version of record. For information on re-use, please refer to the publisher’s terms and conditions. |
| Keywords: | Science & Technology, Physical Sciences, Astronomy & Astrophysics, gravitational lensing, weak, dark matter, large-scale structure of Universe, cosmology: observations, radio continuum: galaxies, RADIOOPTICAL GALAXY SHAPE, SHEAR MEASUREMENT, POWER SPECTRUM, CALIBRATION, CONSTRAINTS, IMPACT, SEXTRACTOR, COSMOLOGY, FORECASTS, KIDS-450 |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Physics and Astronomy |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10117050 |
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