zpix-SURVEY-PROGRAM.fits¶

Summary:: This file contatenates the individual healpix-based Redrock redshift catalogs into a single file per SURVEY and PROGRAM.
Naming Convention:: ztile-SURVEY-PROGRAM.fits, where SURVEY is e.g. main or sv1 and PROGRAM is e.g. bright or ``dark.
Regex:: zpix-(cmx|main|sv1|sv2|sv3|special)-(backup|bright|dark|other)\.fits
File Type:: FITS, 296 MB

Contents¶

Number	EXTNAME	Type	Contents
HDU0		IMAGE	Empty
HDU1	ZCATALOG	BINTABLE	Redshift catalog joined with target catalog
HDU2	EXP_FIBERMAP	BINTABLE	Per-exposure entries from input fibermaps

FITS Header Units¶

HDU0¶

This HDU has no non-standard required keywords.

Empty HDU.

HDU1¶

EXTNAME = ZCATALOG

Redshift catalog joined with the targeting metadata from the REDSHIFTS and FIBERMAP HDUs of the input redrock files

TEMNAMnn and TEMVERnn record the redrock template names and versions used for the redshift fits.

Required Header Keywords¶

Required Header Keywords Table

KEY	Example Value	Type	Comment
NAXIS1	631	int	width of table in bytes
NAXIS2	139728	int	number of rows in table
LONGSTRN	OGIP 1.0	str
RRVER	0.15.0	str	Redrock version
TEMNAM00	GALAXY	str	Redrock template 00 name
TEMVER00	2.6	str	Redrock template 00 version
TEMNAM01	QSO	str
TEMVER01	0.1	str
TEMNAM02	STAR:::A	str
TEMVER02	0.1	str
TEMNAM03	STAR:::B	str
TEMVER03	0.1	str
TEMNAM04	STAR:::CV	str
TEMVER04	0.1	str
TEMNAM05	STAR:::F	str
TEMVER05	0.1	str
TEMNAM06	STAR:::G	str
TEMVER06	0.1	str
TEMNAM07	STAR:::K	str
TEMVER07	0.1	str
TEMNAM08	STAR:::M	str
TEMVER08	0.1	str
TEMNAM09	STAR:::WD	str
TEMVER09	0.1	str
SPGRP	healpix	str	Spectral grouping method
HPXNSIDE	64	int	Healpix nside
HPXNEST	True	str	Nested healpix (not ring)
SURVEY [1]	sv2	str	DESI sub-survey (e.g. sv1, sv3, main)
PROGRAM [1]	dark	str	DESI program (e.g. dark, bright)

Required Data Table Columns¶

Name	Type	Units	Description
TARGETID	int64		ID (unique to file? and the whole survey?)
SURVEY [1]	char[7]		Survey name
PROGRAM [1]	char[6]		DESI program type - BRIGHT, DARK, BACKUP, OTHER
HEALPIX	int32		HEALPixel containing this location at NSIDE=64 in the NESTED scheme
SPGRPVAL	int32		Value by which spectra are grouped for a coadd (e.g. a YEARMMDD night)
Z	float64		Redshift measured by Redrock
ZERR	float64		Redshift error from redrock
ZWARN	int64		Redshift warning bitmask from Redrock
CHI2	float64		Best fit chi squared
COEFF	float64[10]		Redrock template coefficients
NPIXELS	int64		Number of unmasked pixels contributing to the Redrock fit
SPECTYPE	char[6]		Spectral type of Redrock best fit template (e.g. GALAXY, QSO, STAR)
SUBTYPE	char[20]		Spectral subtype
NCOEFF	int64		Number of Redrock template coefficients
DELTACHI2	float64		chi2 difference between first- and second-best redrock template fits
COADD_FIBERSTATUS	int32		bitwise-AND of input FIBERSTATUS
TARGET_RA	float64	deg	Barycentric Right Ascension in ICRS
TARGET_DEC	float64	deg	Barycentric Declination in ICRS
PMRA	float32	mas yr^-1	Reference catalog proper motion in the RA direction
PMDEC	float32	mas yr^-1	Reference catalog proper motion in the Dec direction
REF_EPOCH	float32	yr	Reference catalog reference epoch (e.g., 2015.5 for Gaia DR2)
FA_TARGET	int64		Targeting bit internally used by fiberassign (linked with FA_TYPE)
FA_TYPE	binary		Fiberassign internal target type (science, standard, sky, safe, suppsky)
OBJTYPE	char[3]		Object type: TGT, SKY, NON, BAD
SUBPRIORITY	float64		Random subpriority [0-1] to break assignment ties
OBSCONDITIONS	int32		Flag the target to be observed in graytime.
RELEASE	int16		Legacy Surveys (LS) Release
BRICKNAME	char[8]		Brick name from tractor input
BRICKID	int32		Brick ID from tractor input
BRICK_OBJID	int32		OBJID (unique to brick, but not to file)
MORPHTYPE	char[4]		Morphological Model type
EBV	float32	mag	Galactic extinction E(B-V) reddening from SFD98
FLUX_G	float32	nanomaggy	LS flux from tractor input (g)
FLUX_R	float32	nanomaggy	LS flux from tractor input (r)
FLUX_Z	float32	nanomaggy	LS flux from tractor input (z)
FLUX_W1	float32	nanomaggy	WISE flux in W1
FLUX_W2	float32	nanomaggy	WISE flux in W2
FLUX_IVAR_G	float32	nanomaggy^-2	Inverse Variance of FLUX_G
FLUX_IVAR_R	float32	nanomaggy^-2	Inverse Variance of FLUX_R
FLUX_IVAR_Z	float32	nanomaggy^-2	Inverse Variance of FLUX_Z
FLUX_IVAR_W1	float32	nanomaggy^-2	Inverse Variance of FLUX_W1
FLUX_IVAR_W2	float32	nanomaggy^-2	Inverse Variance of FLUX_W2
FIBERFLUX_G	float32	nanomaggy	Predicted g-band flux within a fiber of diameter 1.5 arcsec from this object in 1 arcsec Gaussian seeing
FIBERFLUX_R	float32	nanomaggy	Predicted r-band flux within a fiber of diameter 1.5 arcsec from this object in 1 arcsec Gaussian seeing
FIBERFLUX_Z	float32	nanomaggy	Predicted z-band flux within a fiber of diameter 1.5 arcsec from this object in 1 arcsec Gaussian seeing
FIBERTOTFLUX_G	float32	nanomaggy	Predicted g-band flux within a fiber of diameter 1.5 arcsec from all sources at this location in 1 arcsec Gaussian seeing
FIBERTOTFLUX_R	float32	nanomaggy	Predicted r-band flux within a fiber of diameter 1.5 arcsec from all sources at this location in 1 arcsec Gaussian seeing
FIBERTOTFLUX_Z	float32	nanomaggy	Predicted z-band flux within a fiber of diameter 1.5 arcsec from all sources at this location in 1 arcsec Gaussian seeing
MASKBITS	int16		Bitwise mask indicating that an object touches a pixel in the `coadd///maskbits` maps, as cataloged on the DR9 bitmasks page
SERSIC	float32		Power-law index for the Sersic profile model (`type="SER"`)
SHAPE_R	float32	arcsec	Half-light radius of galaxy model for galaxy type `type` (>0)
SHAPE_E1	float32		Ellipticity component 1 of galaxy model for galaxy type `type`
SHAPE_E2	float32		Ellipticity component 2 of galaxy model for galaxy type `type`
REF_ID	int64		Tyc11,000,000+Tyc210+Tyc3 for Tycho-2; “sourceid” for Gaia DR2
REF_CAT	char[2]		Reference catalog source for this star: “T2” for Tycho-2, “G2” for Gaia DR2, “L3” for the SGA, empty otherwise
GAIA_PHOT_G_MEAN_MAG	float32	mag	Gaia G band magnitude
GAIA_PHOT_BP_MEAN_MAG	float32	mag	Gaia BP band magnitude
GAIA_PHOT_RP_MEAN_MAG	float32	mag	Gaia RP band magnitude
PARALLAX	float32	mas	Reference catalog parallax
PHOTSYS	char[1]		‘N’ for the MzLS/BASS photometric system, ‘S’ for DECaLS
PRIORITY_INIT	int64		Target initial priority from target selection bitmasks and OBSCONDITIONS
NUMOBS_INIT	int64		Initial number of observations for target calculated across target selection bitmasks and OBSCONDITIONS
CMX_TARGET [1]	int64		Target selection bitmask for commissioning
SV1_DESI_TARGET [1]	int64		DESI (dark time program) target selection bitmask for SV1
SV1_BGS_TARGET [1]	int64		BGS (bright time program) target selection bitmask for SV1
SV1_MWS_TARGET [1]	int64		MWS (bright time program) target selection bitmask for SV1
SV1_SCND_TARGET [1]	int64		Secondary target selection bitmask for SV1
SV2_DESI_TARGET [1]	int64		DESI (dark time program) target selection bitmask for SV2
SV2_BGS_TARGET [1]	int64		BGS (bright time program) target selection bitmask for SV2
SV2_MWS_TARGET [1]	int64		MWS (bright time program) target selection bitmask for SV2
SV2_SCND_TARGET [1]	int64		Secondary target selection bitmask for SV2
SV3_DESI_TARGET [1]	int64		DESI (dark time program) target selection bitmask for SV3
SV3_BGS_TARGET [1]	int64		BGS (bright time program) target selection bitmask for SV3
SV3_MWS_TARGET [1]	int64		MWS (bright time program) target selection bitmask for SV3
SV3_SCND_TARGET [1]	int64		Secondary target selection bitmask for SV3
DESI_TARGET	int64		DESI (dark time program) target selection bitmask
BGS_TARGET	int64		BGS (bright time program) target selection bitmask
MWS_TARGET	int64		MWS (bright time program) target selection bitmask
SCND_TARGET [1]	int64		Secondary target selection bitmask
PLATE_RA	float64	deg	Barycentric Right Ascension in ICRS to be used by PlateMaker
PLATE_DEC	float64	deg	Barycentric Declination in ICRS to be used by PlateMaker
COADD_NUMEXP	int16		Number of exposures in coadd
COADD_EXPTIME	float32	s	Summed exposure time for coadd
COADD_NUMNIGHT	int16		Number of nights in coadd
COADD_NUMTILE	int16		Number of tiles in coadd
MEAN_DELTA_X	float32	mm	Mean (over exposures) fiber difference requested - actual CS5 X location on focal plane
RMS_DELTA_X	float32	mm	RMS (over exposures) of the fiber difference between measured and requested CS5 X location on focal plane
MEAN_DELTA_Y	float32	mm	Mean (over exposures) fiber difference requested - actual CS5 Y location on focal plane
RMS_DELTA_Y	float32	mm	RMS (over exposures) of the fiber difference between measured and requested CS5 Y location on focal plane
MEAN_FIBER_RA	float64	deg	Mean (over exposures) RA of actual fiber position
STD_FIBER_RA	float32	arcsec	Standard deviation (over exposures) of RA of actual fiber position
MEAN_FIBER_DEC	float64	deg	Mean (over exposures) DEC of actual fiber position
STD_FIBER_DEC	float32	arcsec	Standard deviation (over exposures) of DEC of actual fiber position
MEAN_PSF_TO_FIBER_SPECFLUX	float32		Mean of input exposures fraction of light from point-like source captured by 1.5 arcsec diameter fiber given atmospheric seeing
TSNR2_GPBDARK_B	float32		template (S/N)^2 for dark targets in guider pass band on B
TSNR2_ELG_B	float32		ELG B template (S/N)^2
TSNR2_GPBBRIGHT_B	float32		template (S/N)^2 for bright targets in guider pass band on B
TSNR2_LYA_B	float32		LYA B template (S/N)^2
TSNR2_BGS_B	float32		BGS B template (S/N)^2
TSNR2_GPBBACKUP_B	float32		template (S/N)^2 for backup targets in guider pass band on B
TSNR2_QSO_B	float32		QSO B template (S/N)^2
TSNR2_LRG_B	float32		LRG B template (S/N)^2
TSNR2_GPBDARK_R	float32		template (S/N)^2 for dark targets in guider pass band on R
TSNR2_ELG_R	float32		ELG R template (S/N)^2
TSNR2_GPBBRIGHT_R	float32		template (S/N)^2 for bright targets in guider pass band on R
TSNR2_LYA_R	float32		LYA R template (S/N)^2
TSNR2_BGS_R	float32		BGS R template (S/N)^2
TSNR2_GPBBACKUP_R	float32		template (S/N)^2 for backup targets in guider pass band on R
TSNR2_QSO_R	float32		QSO R template (S/N)^2
TSNR2_LRG_R	float32		LRG R template (S/N)^2
TSNR2_GPBDARK_Z	float32		template (S/N)^2 for dark targets in guider pass band on Z
TSNR2_ELG_Z	float32		ELG Z template (S/N)^2
TSNR2_GPBBRIGHT_Z	float32		template (S/N)^2 for bright targets in guider pass band on Z
TSNR2_LYA_Z	float32		LYA Z template (S/N)^2
TSNR2_BGS_Z	float32		BGS Z template (S/N)^2
TSNR2_GPBBACKUP_Z	float32		template (S/N)^2 for backup targets in guider pass band on Z
TSNR2_QSO_Z	float32		QSO Z template (S/N)^2
TSNR2_LRG_Z	float32		LRG Z template (S/N)^2
TSNR2_GPBDARK	float32		template (S/N)^2 for dark targets in guider pass band
TSNR2_ELG	float32		ELG template (S/N)^2 summed over B,R,Z
TSNR2_GPBBRIGHT	float32		template (S/N)^2 for bright targets in guider pass band
TSNR2_LYA	float32		LYA template (S/N)^2 summed over B,R,Z
TSNR2_BGS	float32		BGS template (S/N)^2 summed over B,R,Z
TSNR2_GPBBACKUP	float32		template (S/N)^2 for backup targets in guider pass band
TSNR2_QSO	float32		QSO template (S/N)^2 summed over B,R,Z
TSNR2_LRG	float32		LRG template (S/N)^2 summed over B,R,Z
SV_NSPEC [1]	int32		Number of coadded spectra for this TARGETID in SV (SV1+2+3)
SV_PRIMARY [1]	logical		Boolean flag (True/False) for the primary coadded spectrum in SV (SV1+2+3)
MAIN_NSPEC [1]	int32		Number of coadded spectra for this TARGETID in Main survey
MAIN_PRIMARY [1]	logical		Boolean flag (True/False) for the primary coadded spectrum in Main survey
ZCAT_NSPEC	int16		Number of times this TARGETID appears in this catalog
ZCAT_PRIMARY	logical		Boolean flag (True/False) for the primary coadded spectrum in this zcatalog

Note: zpix files do not have SV_NSPEC or SV_PRIMARY columns; these are added when the zpix files are combined into zall-pix files. MAIN_NSPEC and MAIN_PRIMARY are reserved for future data releases for the DESI Main Survey.

HDU2¶

EXTNAME = EXP_FIBERMAP

Input fibermap entries for columns that apply per-exposure and can’t be coadded, e.g. the individual TILEIDs and FIBERs on which each target was observed.

Required Header Keywords¶

Required Header Keywords Table

KEY	Example Value	Type	Comment
NAXIS1	162	int	width of table in bytes
NAXIS2	1374500	int	number of rows in table

Required Data Table Columns¶

Name	Type	Units	Description
TARGETID	int64		Unique DESI target ID
PRIORITY	int32		Target current priority
SUBPRIORITY	float64		Random subpriority [0-1) to break assignment ties
NIGHT	int32		Night of observation (YYYYMMDD) starting at local noon before observations start
EXPID	int32		DESI Exposure ID number
MJD	float64		Modified Julian Date when shutter was opened for this exposure
TILEID	int32		Unique DESI tile ID
EXPTIME	float64	s	Length of time shutter was open
PETAL_LOC	int16		Petal location [0-9]
DEVICE_LOC	int32		Device location on focal plane [0-523]
LOCATION	int64		Location on the focal plane PETAL_LOC*1000 + DEVICE_LOC
FIBER	int32		Fiber ID on the CCDs [0-4999]
FIBERSTATUS	int32		Fiber status mask. 0=good
FIBERASSIGN_X	float32	mm	Fiberassign expected CS5 X location on focal plane
FIBERASSIGN_Y	float32	mm	Fiberassign expected CS5 Y location on focal plane
LAMBDA_REF	float32	Angstrom	Requested wavelength at which targets should be centered on fibers
PLATE_RA	float64	deg	Barycentric Right Ascension in ICRS to be used by PlateMaker
PLATE_DEC	float64	deg	Barycentric Declination in ICRS to be used by PlateMaker
NUM_ITER	int64		Number of positioner iterations
FIBER_X	float64	mm	CS5 X location requested by PlateMaker
FIBER_Y	float64	mm	CS5 Y location requested by PlateMaker
DELTA_X	float64	mm	CS5 X requested minus actual position
DELTA_Y	float64	mm	CS5 Y requested minus actual position
FIBER_RA	float64	deg	RA of actual fiber position
FIBER_DEC	float64	deg	DEC of actual fiber position
PSF_TO_FIBER_SPECFLUX	float64		fraction of light from point-like source captured by 1.5 arcsec diameter fiber given atmospheric seeing

Notes and Examples¶

For the SURVEY=cmx m33 tile (TILEID=80615) tile and all the SURVEY=sv1 tiles (except TILEID=80971-80976, the dc3r2 ones), proper-motion correction was applied at the fiberassign design step; thus the following columns can have different values than in the desitarget products: TARGET_RA, TARGET_DEC, REF_EPOCH, PLATE_RA, PLATE_DEC, and PLATE_REF_EPOCH.

For targets with a non-zero proper motion, FIBER_RA and FIBER_DEC refer to the position at the reference epoch (but note that the proper-motion correction has been applied at the time of the observation, it is just not recorded in FIBER_RA and FIBER_DEC).