Preliminary Target Selection for the DESI Bright Galaxy Survey (BGS)
Omar Ruiz-Macias, Pauline Zarrouk, Shaun Cole, P. Norberg, C. M. Baugh, D. Brooks, Arjun Dey, Yutong Duan, Sarah Eftekharzadeh, Daniel J. Eisenstein, J. E. Forero-Romero, E. Gaztañaga, ChangHoon Hahn, R. Kehoe, Martin Landriau, Dustin Lang, M. E. Levi, J. R. Lucey, Aaron Meisner, John Moustakas, Adam D. Myers, N. Palanque‐Delabrouille, Claire Poppett, Francisco Prada, Anand Raichoor, David J. Schlegel, M. Schubnell, G. Tarlé, David H. Weinberg, Michael Wilson, Christophe Yèche
Abstract
Abstract The Dark Energy Spectroscopic Instrument (DESI) will execute a nearly magnitude-limited survey of low redshift galaxies (0.05 ≤ z ≤ 0.4, median z ≈ 0.2). Clustering analyses of this Bright Galaxy Survey (BGS) will yield the most precise measurements to date of baryon acoustic oscillations and redshift-space distortions at low redshift. DESI BGS will comprise two target classes: (i) BRIGHT ( r < 19.5 mag), and (ii) FAINT (19.5 < r < 20 mag). Here we present a summary of the star-galaxy separation, and different photometric and geometrical masks, used in BGS to reduce the number of spurious targets. The selection results in a total density of ∼800 objects deg −2 for the BRIGHT and ∼600 objects deg −2 for the FAINT selections. A full characterization of the BGS selection can be found in Ruiz-Macias et al.