학술논문
DESI and DECaLS (D&D): galaxy-galaxy lensing measurements with 1% survey and its forecast
Document Type
Working Paper
Author
Yao, Ji; Shan, Huanyuan; Zhang, Pengjie; Jullo, Eric; Kneib, Jean-Paul; Yu, Yu; Zu, Ying; Brooks, David; de la Macorra, Axel; Doel, Peter; Font-Ribera, Andreu; Gontcho, Satya Gontcho A; Kisner, Theodore; Landriau, Martin; Meisner, Aaron; Miquel, Ramon; Nie, Jundan; Poppett, Claire; Prada, Francisco; Schubnell, Michael; Magana, Mariana Vargas; Zhou, Zhimin
Source
Subject
Language
Abstract
The shear measurement from DECaLS (Dark Energy Camera Legacy Survey) provides an excellent opportunity for galaxy-galaxy lensing study with DESI (Dark Energy Spectroscopic Instrument) galaxies, given the large ($\sim 9000$ deg$^2$) sky overlap. We explore this potential by combining the DESI 1\% survey and DECaLS DR8. With $\sim 106$ deg$^2$ sky overlap, we achieve significant detection of galaxy-galaxy lensing for BGS and LRG as lenses. Scaled to the full BGS sample, we expect the statistical errors to improve from $18(12)\%$ to a promising level of $2(1.3)\%$ at $\theta>8^{'}(<8^{'})$. This brings stronger requirements for future systematics control. To fully realize such potential, we need to control the residual multiplicative shear bias $|m|<0.01$ and the bias in the mean redshift $|\Delta z|<0.015$. We also expect significant detection of galaxy-galaxy lensing with DESI LRG/ELG full samples as lenses, and cosmic magnification of ELG through cross-correlation with low-redshift DECaLS shear. {If such systematical error control can be achieved,} we find the advantages of DECaLS, comparing with KiDS (Kilo Degree Survey) and HSC (Hyper-Suprime Cam), are at low redshift, large-scale, and in measuring the shear-ratio (to $\sigma_R\sim 0.04$) and cosmic magnification.
Comment: submitted to MNRAS
Comment: submitted to MNRAS