The Impact of Strong Gravitational Lensing on Observed Lyman-Break Galaxy Numbers at 4<z<8 in the GOODS and the XDF Blank Fields

Understand

Detection of Lyman-Break Galaxies (LBGs) at high-redshift can be affected by gravitational lensing induced by foreground deflectors not only in galaxy clusters, but also in blank fields.

• We quantify the impact of strong magnification in the samples of $B$, $V$, $i$, $z$ $\&$ $Y$ LBGs ($4\lesssim z \lesssim8$) observed in the XDF and GOODS/CANDELS fields, by investigating the proximity of dropouts to foreground objects.
• We find that $\sim6\%$ of bright LBGs ($m_{H_{160}}<26$) at $z\sim7$ have been strongly lensed ($\mu>2$) by foreground objects.
• This fraction decreases from $\sim 3.5\%$ at $z\sim6$ to $\sim1.5\%$ at $z\sim4$.