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Visual Inspection Catalogs

Overview

These catalogs contain the visual inspection (VI) information of the deep co-added spectra of DESI targets observed during the first phase of Survey Validation (sv1). These catalogs have been used to characterize the performance of the DESI operation, inform the main survey target selection scheme, and identify problematic spectral features and rare astrophysical objects.

Descriptions of the VI process, and the compilation of the catalogs and their usage for quantifying the performance of the DESI survey are summarized in Lan et al. (2023) for galaxies (i.e. BGS, LRGs, and ELGs) and in Alexander et al. (2023) for quasars.

Data Access

Data URL: https://data.desi.lbl.gov/public/edr/vac/edr/vi/v1.0/

NERSC access: 

/global/cfs/cdirs/desi/public/edr/vac/edr/vi/v1.0/

Documentation

List of files

Target Number of Sources File Name
Bright Galaxy Survey 2,718 EDR_VI_BGS_v1.csv
Luminous Red Galaxies 3,561 EDR_VI_LRG_v1.csv
Emission Line Galaxies 10,315 EDR_VI_ELG_v1.csv
Quasars 3,779 DR_VI_QSO_v1.csv
Missed Quasar Sample 1,717 EDR_VI_missed_QSO_v1.csv

Data model

Name Format Units Description
TARGETID int64 – Unique identifier for each object observed by DESI
TILEID int32 – Tile ID
FIBER int32 – Fiber ID
TARGET_RA float64 degree Right Ascension in decimal degrees (J2000)
TARGET_DEC float64 degree Declination in decimal degrees (J2000)
VI_Z float64 – VI redshift
VI_QUALITY float32 – VI quality (4=confident, 3=probable, 2=possible, 1=bad, 0=no_signal; DESI uses \(\geq\) 2.5 for science)
VI_SPECTYPE string – VI spectype (star, galaxy, or QSO)

For more details on the VI quality flags, please refer to Section 2 of Lan et al. (2023) and Alexander et al. (2023) for specific details on the galaxy and quasar catalogs, respectively.

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