The HectoMAP Redshift Survey: First Data Release

Abstract HectoMAP is a dense, red-selected redshift survey to limiting r = 21.3 mag covering 55 deg 2 in contiguous 1.°5 strip across the northern sky. This region also covered by Subaru/Hyper Suprime-Cam (HSC) Subaru Strategic Program photometric enabling range of applications that combine dense foreground with both strong and weak lensing maps. The median exceeds 0.3 throughout region, mean density ?2000 galaxies ?2 . Here we report total 17,313 redshifts first data release 8.7 We include derived quantities D n 4000 stellar mass for nearly all objects. Among these galaxies, 8117 constitute 79% complete subsample ? 20.5 mag, an additional 4318 68% < (mag) 21.3. As examples strengths data, discuss two applications: refined membership redMaPPer photometrically selected clusters test HSC redshifts. highlight remarkable system. comparison spectroscopic uncovers subtle systematic issues