English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

UNIONS is an ongoing collaboration that will provide the largest deepphotometric survey of the Northern sky in four optical bands to date. As partof this collaboration, CFIS is taking $r$-band data with an average seeing of0.65 arcsec, which is complete to magnitude 24.5 and thus ideal forweak-lensing studies. We perform the first weak-lensing analysis of CFIS$r$-band data over an area spanning 1700 deg$^2$ of the sky. We create acatalogue with measured shapes for 40 million galaxies, corresponding to aneffective density of 6.8 galaxies per square arcminute, and demonstrate a lowlevel of systematic biases. This work serves as the basis for furthercosmological studies using the full UNIONS survey of 4800 deg$^2$ whencompleted. Here we present ShapePipe, a newly developed weak-lensing pipeline.This pipeline makes use of state-of-the-art methods such as Ngmix for accurategalaxy shape measurement. Shear calibration is performed with metacalibration.We carry out extensive validation tests on the Point Spread Function (PSF), andon the galaxy shapes. In addition, we create realistic image simulations tovalidate the estimated shear. We quantify the PSF model accuracy and show thatthe level of systematics is low as measured by the PSF residuals. Their effecton the shear two-point correlation function is sub-dominant compared to thecosmological contribution on angular scales <100 arcmin. The additive shearbias is below 5x$10^{-4}$, and the residual multiplicative shear bias is atmost $10^{-3}$ as measured on image simulations. Using COSEBIs we show thatthere are no significant B-modes present in second-order shear statistics. Wepresent convergence maps and see clear correlations of the E-mode with knowncluster positions. We measure the stacked tangential shear profile aroundPlanck clusters at a significance higher than $4\sigma$.

ShapePipe: a new shape measurement pipeline and weak-lensing application to UNIONS/CFIS data