Preliminary Target Selection for the DESI Emission Line Galaxy (ELG) Sample
Anand Raichoor, Daniel J. Eisenstein, Tanveer Karim, Jeffrey A. Newman, John Moustakas, David D. Brooks, Kyle S. Dawson, Arjun Dey, Yutong Duan, Sarah Eftekharzadeh, Enrique Gaztañaga, Robert Kehoe, Martin Landriau, Dustin Lang, Jae H. Lee, Michael E. Levi, Aaron M. Meisner, Adam D. Myers, Nathalie Palanque-Delabrouille, Claire Poppett, Francisco Prada, Ashley J. Ross, David J. Schlegel, Michael Schubnell, Ryan Staten, Gregory Tarlé, Rita Tojeiro, Christophe Yèche, Rongpu Zhou
Abstract
Abstract DESI will precisely constrain cosmic expansion and the growth of structure by collecting ∼35 million redshifts across ∼80% of cosmic history and one third of the sky to study Baryon Acoustic Oscillations (BAO) and Redshift Space Distortions (RSD). We present a preliminary target selection for an Emission Line Galaxy (ELG) sample, which will comprise about half of all DESI tracers. The selection consists of a g -band magnitude cut and a ( g − r ) versus ( r − z ) color box, which we validate using HSC/PDR2 photometric redshifts and DEEP2 spectroscopy. The ELG target density should be ∼2400 deg −2 , with ∼65% of ELG redshifts reliably within a redshift range of 0.6 < z < 1.6. ELG targeting for DESI will be finalized during a “Survey Validation” phase.