%0 Generic %1 chaussidon2022target %A Chaussidon, Edmond %A Yèche, Christophe %A Palanque-Delabrouille, Nathalie %A Alexander, David M. %A Yang, Jinyi %A Ahlen, Steven %A Bailey, Stephen. %A Brooks, David %A Cai, Zheng %A Chabanier, Solène %A Davis, Tamara M. %A Dawson, Kyle %A de la Macorra, Axel %A Dey, Arjun %A Dey, Biprateep %A Eftekharzadeh, Sarah %A Eisenstein, Daniel J. %A Fanning, Kevin %A Font-Ribera, Andreu %A Gaztañaga, Enrique %A Gontcho, Satya Gontcho A %A Gonzalez-Morales, Alma X. %A Guy, Julien %A Herrera-Alcantar, Hiram K. %A Honscheid, Klaus %A Ishak, Mustapha %A Jiang, Linhua %A Juneau, Stephanie %A Kehoe, Robert %A Kisner, Theodore %A Kovács, Andras %A Kremin, Anthony %A Lan, Ting-Wen %A Landriau, Martin %A Guillou, Laurent Le %A Levi, Michael E. %A Magneville, Christophe %A Martini, Paul %A Meisner, Aaron M. %A Moustakas, John %A Muñoz-Gutiérrez, Andrea %A Myers, Adam D. %A Newman, Jeffrey A. %A Nie, Jundan %A Percival, Will J. %A Poppett, Claire %A Prada, Francisco %A Raichoor, Anand %A Ravoux, Corentin %A Ross, Ashley J. %A Schlafly, Edward %A Schlegel, David %A Tan, Ting %A Tarlé, Gregory %A Zhou, Rongpu %A Zhou, Zhimin %A Zou, Hu %D 2022 %K library %T Target Selection and Validation of DESI Quasars %U http://arxiv.org/abs/2208.08511 %X The Dark Energy Spectroscopic Instrument (DESI) survey will measure large-scale structures using quasars as direct tracers of dark matter in the redshift range 0.9<z<2.1 and using Ly-alpha forests in quasar spectra at z>2.1. We present several methods to select candidate quasars for DESI, using input photometric imaging in three optical bands (g, r, z) from the DESI Legacy Imaging Surveys and two infrared bands (W1, W2) from the Wide-field Infrared Explorer (WISE). These methods were extensively tested during the Survey Validation of DESI. In this paper, we report on the results obtained with the different methods and present the selection we optimized for the DESI main survey. The final quasar target selection is based on a Random Forest algorithm and selects quasars in the magnitude range 16.5<r<23. Visual selection of ultra-deep observations indicates that the main selection consists of 71% quasars, 16% galaxies, 6% stars and 7% inconclusive spectra. Using the spectra based on this selection, we build an automated quasar catalog that achieves a >99% purity for a nominal effective exposure time of ~1000s. With a 310 per sq. deg. target density, the main selection allows DESI to select more than 200 QSOs per sq. deg. (including 60 quasars with z>2.1), exceeding the project requirements by 20%. The redshift distribution of the selected quasars is in excellent agreement with quasar luminosity function predictions.

@misc{chaussidon2022target, abstract = {The Dark Energy Spectroscopic Instrument (DESI) survey will measure large-scale structures using quasars as direct tracers of dark matter in the redshift range 0.9<z<2.1 and using Ly-alpha forests in quasar spectra at z>2.1. We present several methods to select candidate quasars for DESI, using input photometric imaging in three optical bands (g, r, z) from the DESI Legacy Imaging Surveys and two infrared bands (W1, W2) from the Wide-field Infrared Explorer (WISE). These methods were extensively tested during the Survey Validation of DESI. In this paper, we report on the results obtained with the different methods and present the selection we optimized for the DESI main survey. The final quasar target selection is based on a Random Forest algorithm and selects quasars in the magnitude range 16.5<r<23. Visual selection of ultra-deep observations indicates that the main selection consists of 71% quasars, 16% galaxies, 6% stars and 7% inconclusive spectra. Using the spectra based on this selection, we build an automated quasar catalog that achieves a >99% purity for a nominal effective exposure time of ~1000s. With a 310 per sq. deg. target density, the main selection allows DESI to select more than 200 QSOs per sq. deg. (including 60 quasars with z>2.1), exceeding the project requirements by 20%. The redshift distribution of the selected quasars is in excellent agreement with quasar luminosity function predictions.}, added-at = {2022-08-19T05:25:12.000+0200}, author = {Chaussidon, Edmond and Yèche, Christophe and Palanque-Delabrouille, Nathalie and Alexander, David M. and Yang, Jinyi and Ahlen, Steven and Bailey, Stephen. and Brooks, David and Cai, Zheng and Chabanier, Solène and Davis, Tamara M. and Dawson, Kyle and de la Macorra, Axel and Dey, Arjun and Dey, Biprateep and Eftekharzadeh, Sarah and Eisenstein, Daniel J. and Fanning, Kevin and Font-Ribera, Andreu and Gaztañaga, Enrique and Gontcho, Satya Gontcho A and Gonzalez-Morales, Alma X. and Guy, Julien and Herrera-Alcantar, Hiram K. and Honscheid, Klaus and Ishak, Mustapha and Jiang, Linhua and Juneau, Stephanie and Kehoe, Robert and Kisner, Theodore and Kovács, Andras and Kremin, Anthony and Lan, Ting-Wen and Landriau, Martin and Guillou, Laurent Le and Levi, Michael E. and Magneville, Christophe and Martini, Paul and Meisner, Aaron M. and Moustakas, John and Muñoz-Gutiérrez, Andrea and Myers, Adam D. and Newman, Jeffrey A. and Nie, Jundan and Percival, Will J. and Poppett, Claire and Prada, Francisco and Raichoor, Anand and Ravoux, Corentin and Ross, Ashley J. and Schlafly, Edward and Schlegel, David and Tan, Ting and Tarlé, Gregory and Zhou, Rongpu and Zhou, Zhimin and Zou, Hu}, biburl = {https://www.bibsonomy.org/bibtex/2a3f4cfeaec3ddbe6412710f606ac1ab6/gpkulkarni}, description = {Target Selection and Validation of DESI Quasars}, interhash = {5bad84529f6a2cfc4ff3a47aca2c2bc4}, intrahash = {a3f4cfeaec3ddbe6412710f606ac1ab6}, keywords = {library}, note = {cite arxiv:2208.08511Comment: 21 pages, 21 figures, submitted to AJ, one of a suite of 8 papers detailing targeting for DESI}, timestamp = {2022-08-19T05:25:12.000+0200}, title = {Target Selection and Validation of DESI Quasars}, url = {http://arxiv.org/abs/2208.08511}, year = 2022 }