Target Selection and Validation of DESI Quasars

Chaussidon, Edmond; Yèche, Ch; Palanque-Delabrouille, N.; Alexander, David; Yang, Jinyi; Ahlen, S. P.; Bailey, S.; Cai, Zheng; Chabanier, Solène; Davis, Tamara M.; Dawson, Kyle; Macorra, Axel de la; Dey, Arjun; Dey, Biprateep; Eftekharzadeh, Sarah; Eisenstein, Daniel J.; Fanning, Kevin; Font-Ribera, Andreu; Gaztañaga, E.; Gontcho, Satya Gontcho A; González‐Morales, Alma X.; Guy, J.; Herrera-Alcantar, Hiram K.; Honscheid, K.; Ishak, Mustapha; Jiang, Linhua; Juneau, Stéphanie; Kehoe, R.; Kisner, T. S.; Kovács, András; Kremin, Anthony; Lan, Ting-Wen; Landriau, Martin; Guillou, L. Le; Levi, Michael; Magneville, C.; Martini, Paul; Meisner, Aaron M.; Moustakas, John; Muñoz‐Gutiérrez, Andrea; Myers, Adam D.; Newman, Jeffrey A.; Nie, Jundan; Percival, Will J.; Poppett, Claire; Prada, Francisco; Raichoor, Anand; Ravoux, Corentin; Ross, Ashley J.; Schlafly, Edward F.; Schlegel, David J.; Tan, Ting; Tarlè, G.; Zhou, Rongpu; Zhang, Zhimin; Zou, Hu

doi:10.3847/1538-4357/acb3c2

Cited by 69 publications

(52 citation statements)

References 55 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, the seemingly unusual distribution of these sources in the system was difficult to interpret. Furthermore, the Dark Energy Spectroscopic Instrument targeting overlay in the Sky Viewer incorrectly suggested that the bulk of sources in this system were either quasars or emission line galaxies (see Chaussidon et al 2023 andRaichoor et al 2023 for details on the target selection and expected contamination rates for each class of objects).…”

Section: Delve J1448+1728 (Delve 5)mentioning

confidence: 99%

Six More Ultra-faint Milky Way Companions Discovered in the DECam Local Volume Exploration Survey

Cerny¹,

Martı́nez-Vázquez²,

Drlica-Wagner³

et al. 2023

ApJ

View full text Add to dashboard Cite

We report the discovery of six ultra-faint Milky Way satellites identified through matched-filter searches conducted using Dark Energy Camera (DECam) data processed as part of the second data release of the DECam Local Volume Exploration (DELVE) survey. Leveraging deep Gemini/GMOS-N imaging (for four candidates) as well as follow-up DECam imaging (for two candidates), we characterize the morphologies and stellar populations of these systems. We find that these candidates all share faint absolute magnitudes (M V ≥ −3.2 mag) and old, metal-poor stellar populations (τ > 10 Gyr, [Fe/H] < −1.4 dex). Three of these systems are more extended (r 1/2 > 15 pc), while the other three are compact (r 1/2 < 10 pc). From these properties, we infer that the former three systems (Boötes V, Leo Minor I, and Virgo II) are consistent with ultra-faint dwarf galaxy classifications, whereas the latter three (DELVE 3, DELVE 4, and DELVE 5) are likely ultra-faint star clusters. Using data from the Gaia satellite, we confidently measure the proper motion of Boötes V, Leo Minor I, and DELVE 4, and tentatively detect a proper-motion signal from DELVE 3 and DELVE 5; no signal is detected for Virgo II. We use these measurements to explore possible associations between the newly discovered systems and the Sagittarius dwarf spheroidal, the Magellanic Clouds, and the Vast Polar Structure, finding several plausible associations. Our results offer a preview of the numerous ultra-faint stellar systems that will soon be discovered by the Vera C. Rubin Observatory and highlight the challenges of classifying the faintest stellar systems.

show abstract

Section: Delve J1448+1728 (Delve 5)mentioning

confidence: 99%

Six More Ultra-faint Milky Way Companions Discovered in the DECam Local Volume Exploration Survey

Cerny¹,

Martı́nez-Vázquez²,

Drlica-Wagner³

et al. 2023

ApJ

View full text Add to dashboard Cite

show abstract

“…Interpreting the angular clustering or CMB lensing signal for a sample of quasars requires knowledge of the sample's redshift distribution. Targeted quasar redshift surveys are currently limited to optically bright relatively unobscured quasars (e.g., Lyke et al 2020;Alexander et al 2023;Chaussidon et al 2023), and individual blind redshift surveys lack either the breadth or depth to constrain the redshift distribution of our full sample. In order to obtain a nearly complete and statistically representative estimate of the redshifts of our sample quasars, we therefore look to the well-characterized Boötes and COSMOS (Scoville et al 2007) fields.…”

Section: Redshift Informationmentioning

confidence: 99%

Host Dark Matter Halos of Wide-field Infrared Survey Explorer-selected Obscured and Unobscured Quasars: Evidence for Evolution

Petter

Hickox

Alexander

et al. 2023

ApJ

Self Cite

View full text Add to dashboard Cite

Obscuration in quasars may arise from steep viewing angles along the dusty torus, or instead may represent a distinct phase of supermassive black hole growth. We test these scenarios by probing the host dark matter halo environments of ∼1.4 million Wide-field Infrared Survey Explorer-selected obscured and unobscured quasars at 〈z〉 = 1.4 using angular clustering measurements as well as cross-correlation measurements of quasar positions with the gravitational lensing of the cosmic microwave background. We interpret these signals within a halo occupation distribution framework to conclude that obscured systems reside in more massive effective halos (∼1012.9 h −1 M ⊙) than their unobscured counterparts (∼1012.6 h −1 M ⊙), though we do not detect a difference in the satellite fraction. We find excellent agreement between the clustering and lensing analyses and show that this implies the observed difference is robust to uncertainties in the obscured quasar redshift distribution, highlighting the power of combining angular clustering and weak lensing measurements. This finding appears in tension with models that ascribe obscuration exclusively to orientation of the dusty torus along the line of sight, and instead may be consistent with the notion that some obscured quasars are attenuated by galaxy-scale or circumnuclear material during an evolutionary phase.

show abstract

“…Complementary papers describe the target selection for the dark-time DESI tracers (LRGs; Zhou et al 2023;ELGs;A. Raichoor et al 2023, in preparation;and QSOs;Chaussidon et al 2023) and the Milky Way Survey (MWS; Cooper et al 2023). Myers et al (2023) present how the target selections are implemented in DESI.…”

Section: Introductionmentioning

confidence: 99%

The DESI Bright Galaxy Survey: Final Target Selection, Design, and Validation

Hahn

Wilson

Ruiz-Macias

et al. 2023

Self Cite

View full text Add to dashboard Cite

Over the next 5 yr, the Dark Energy Spectroscopic Instrument (DESI) will use 10 spectrographs with 5000 fibers on the 4 m Mayall Telescope at Kitt Peak National Observatory to conduct the first Stage IV dark energy galaxy survey. At z < 0.6, the DESI Bright Galaxy Survey (BGS) will produce the most detailed map of the universe during the dark-energy-dominated epoch with redshifts of >10 million galaxies spanning 14,000 deg2. In this work, we present and validate the final BGS target selection and survey design. From the Legacy Surveys, BGS will target an r < 19.5 mag limited sample (BGS Bright), a fainter 19.5 < r < 20.175 color-selected sample (BGS Faint), and a smaller low-z quasar sample. BGS will observe these targets using exposure times scaled to achieve homogeneous completeness and cover the footprint three times. We use observations from the Survey Validation programs conducted prior to the main survey along with simulations to show that BGS can complete its strategy and make optimal use of “bright” time. BGS targets have stellar contamination <1%, and their densities do not depend strongly on imaging properties. BGS Bright will achieve >80% fiber assignment efficiency. Finally, BGS Bright and BGS Faint will achieve >95% redshift success over any observing condition. BGS meets the requirements for an extensive range of scientific applications. BGS will yield the most precise baryon acoustic oscillation and redshift-space distortion measurements at z < 0.4. It presents opportunities for new methods that require highly complete and dense samples (e.g., N-point statistics, multitracers). BGS further provides a powerful tool to study galaxy populations and the relations between galaxies and dark matter.

show abstract

Target Selection and Validation of DESI Quasars

Cited by 69 publications

References 55 publications

Six More Ultra-faint Milky Way Companions Discovered in the DECam Local Volume Exploration Survey

Six More Ultra-faint Milky Way Companions Discovered in the DECam Local Volume Exploration Survey

Host Dark Matter Halos of Wide-field Infrared Survey Explorer-selected Obscured and Unobscured Quasars: Evidence for Evolution

The DESI Bright Galaxy Survey: Final Target Selection, Design, and Validation

Contact Info

Product

Resources

About