datcomb_obscon_spec_zdone.fits

Summary:

Compilation of spectroscopic reduction

Naming Convention:

datcomb_{obscon}_spec_zdone.fits, where obscon can be either dark or bright

Regex:

datcomb_(bright|dark)_spec_zdone\.fits

File Type:

FITS, 4 GB

Contents

Number	EXTNAME	Type	Contents
HDU0		IMAGE	Empty
HDU1	ZCATALOG	BINTABLE	Catalog data

FITS Header Units

HDU0

This HDU has no non-standard required keywords.

Empty HDU.

HDU1

EXTNAME = ZCATALOG

Selected columns from the cumulative tiles-based redshift catalogs (CROSS-REF) for the dark/bright program, selecting the data from fiber positioners available to science targets, and joining with the zmtl information (CROSS-REF) for each tile, which is used downstream to select observations that used “good hardware”.

Required Header Keywords

Required Header Keywords Table

KEY	Example Value	Type	Comment
NAXIS1	372	int	length of dimension 1
NAXIS2	11632889	int	length of dimension 2
LONGSTRN [1]	OGIP 1.0	str
SPGRP [1]	cumulative	str
SURVEY [1]	main	str
PROGRAM [1]	dark	str
ZCATVER [1]	v0	str
DESIDR	dr1	str	DESI Data Release

[1] (1,2,3,4,5)

Optional

Required Data Table Columns

Name	Type	Units	Description
TARGETID	int64		Unique DESI target ID
LASTNIGHT	int32		Final night of observation included in a series of coadds
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
LOCATION	int64		Location on the focal plane PETAL_LOC*1000 + DEVICE_LOC
FIBER	int32		Fiber ID on the CCDs [0-4999]
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
FIBERASSIGN_X	float32	mm	Fiberassign expected CS5 X location on focal plane
FIBERASSIGN_Y	float32	mm	Fiberassign expected CS5 Y location on focal plane
PRIORITY	int32		Target current priority
DESI_TARGET	int64		DESI (dark time program) target selection bitmask
BGS_TARGET	int64		BGS (Bright Galaxy Survey) target selection bitmask
TILEID	int32		Unique DESI tile ID
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
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_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_ELG_B	float32		ELG B template (S/N)^2
TSNR2_LYA_B	float32		LYA B template (S/N)^2
TSNR2_BGS_B	float32		BGS B template (S/N)^2
TSNR2_QSO_B	float32		QSO B template (S/N)^2
TSNR2_LRG_B	float32		LRG B template (S/N)^2
TSNR2_ELG_R	float32		ELG R template (S/N)^2
TSNR2_LYA_R	float32		LYA R template (S/N)^2
TSNR2_BGS_R	float32		BGS R template (S/N)^2
TSNR2_QSO_R	float32		QSO R template (S/N)^2
TSNR2_LRG_R	float32		LRG R template (S/N)^2
TSNR2_ELG_Z	float32		ELG Z template (S/N)^2
TSNR2_LYA_Z	float32		LYA Z template (S/N)^2
TSNR2_BGS_Z	float32		BGS Z template (S/N)^2
TSNR2_QSO_Z	float32		QSO Z template (S/N)^2
TSNR2_LRG_Z	float32		LRG Z template (S/N)^2
TSNR2_ELG	float32		ELG template (S/N)^2 summed over B,R,Z
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_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
ZWARN_MTL	int64		The ZWARN from the zmtl file (contains extra bits)
Z_QN	float64		Redshift measured by QuasarNET using line with highest confidence
Z_QN_CONF	float64		Redshift confidence from QuasarNET
IS_QSO_QN	int16		Spectroscopic classification from QuasarNET (1 for a quasar)