spmod_coadd

Summary:

This is the file containing the best-fit models to spectra from FERRE for a given healpix.

Naming Convention:

spmod_coadd-{SURVEY}-{PROGRAM}-{HEALPIX}.fits, where SURVEY is main, special, sv1, sv2, sv3, and PROGRAM is dark, bright, backup, other.

Regex:

spmod_coadd-.*-.*-.*.fits

File Type:

FITS, 50 MB

Contents

Number	EXTNAME	Type	Contents
HDU00		IMAGE	Empty HDU
HDU01	B_WAVELENGTH	IMAGE	Wavelength array of b-channel spectra
HDU02	B_MODEL	BINTABLE	Flux array of best-fit model b-channel spectra and auxiliary quantities
HDU03	R_WAVELENGTH	IMAGE	Wavelength array of r-channel spectra
HDU04	R_MODEL	BINTABLE	Flux array of best-fit model r-channel spectra and auxiliary quantities
HDU05	Z_WAVELENGTH	IMAGE	Wavelength array of z-channel spectra
HDU06	Z_MODEL	BINTABLE	Flux array of best-fit model z-channel spectra and auxiliary quantities
HDU07	FIBERMAP	BINTABLE	Information about objects inherited from targeting
HDU08	SCORES	BINTABLE	Information about spectra quality
HDU09	FILTER	BINTABLE	Spectral filters used for the determination of chemical abundances

FITS Header Units

HDU00

Empty HDU.

Required Header Keywords

Required Header Keywords Table

KEY	Example Value	Type	Comment
DATE	2022-04-03T16:48:32	str	Date of processing
FCONFIG	desi-ms.yaml	str	FERRE config information
HOST	login1	str	machine used
OS	posix	str	Operative system
PLATFORM	Linux 4.4.90-92.45-default	str	OS details
NSPEC	7	int	Number of spectra included
FTIME	234.041	float	Compute time used by FERRE
STIME	900.0	float	Compute time estimated for Slurm
NCORES	16	int	Number of cores in node
NTHREADS	12	int	Maximum number of cores for FERRE
NUMPY	1.17.2	str	NumPy version
ASTROPY	3.2.2	str	AstroPy version
MATPLOTL	3.1.1	str	Matplotlib version
SCIPY	1.3.1	str	SciPy version
YAML	5.1.2	str	Yaml version
PYTHON	3.7.4	str	Python version
PIFERRE	0.4	str	Piferre version
FERRE	5.0.0	str	FERRE version

HDU01

EXTNAME = B_WAVELENGTH

Wavelength array for the b-channel spectra.

Required Header Keywords

Required Header Keywords Table

KEY	Example Value	Type	Comment
NAXIS1	4759	int

Data: FITS image [float64, 4759]

HDU02

EXTNAME = B_MODEL

Best-fit b-channel model fluxes and associated quantities.

Required Header Keywords

Required Header Keywords Table

KEY	Example Value	Type	Comment
NAXIS1	190360	int	length of dimension 1
NAXIS2	7	int	length of dimension 2

Required Data Table Columns

Name	Type	Units	Description
obs	float64[4759]	cgs	Normalized b-channel observed flux as fit by FERRE
err	float64[4759]	cgs	Normalized b-channel observed flux uncertainties
flx	float64[4759]	cgs	Best-fit b-channel model flux in absolute units (f_lambda in cgs units)
fit	float64[4759]	cgs	Best-fit b-channel normalized model flux
abu	float64[4759]	cgs	Best-fit b-channel normalized model flux from the chemical abundance determinations

HDU03

EXTNAME = R_WAVELENGTH

Wavelength array for the r-channel spectra.

Required Header Keywords

Required Header Keywords Table

KEY	Example Value	Type	Comment
NAXIS1	4231	int

Data: FITS image [float64, 4231]

HDU04

EXTNAME = R_MODEL

Best-fit r-channel model fluxes and associated quantities.

Required Header Keywords

Required Header Keywords Table

KEY	Example Value	Type	Comment
NAXIS1	169240	int	length of dimension 1
NAXIS2	7	int	length of dimension 2

Required Data Table Columns

Name	Type	Units	Description
obs	float64[4231]	cgs	Normalized r-channel observed flux as fit by FERRE
err	float64[4231]	cgs	Normalized r-channel observed flux uncertainties
flx	float64[4231]	cgs	Best-fit r-channel model flux in absolute units (f_lambda in cgs units)
fit	float64[4231]	cgs	Best-fit r-channel normalized model flux
abu	float64[4231]	cgs	Best-fit r-channel normalized model flux from the chemical abundance determinations

HDU05

EXTNAME = Z_WAVELENGTH

Wavelength array for the z-channel spectra.

Required Header Keywords

Required Header Keywords Table

KEY	Example Value	Type	Comment
NAXIS1	4797	int

Data: FITS image [float64, 4797]

HDU06

EXTNAME = Z_MODEL

Best-fit z-channel model fluxes and associated quantities.

Required Header Keywords

Required Header Keywords Table

KEY	Example Value	Type	Comment
NAXIS1	191880	int	length of dimension 1
NAXIS2	7	int	length of dimension 2

Required Data Table Columns

Name	Type	Units	Description
obs	float64[4797]	cgs	Normalized z-channel observed flux as fit by FERRE
err	float64[4797]	cgs	Normalized z-channel observed flux uncertainties
flx	float64[4797]	cgs	Best-fit z-channel model flux in absolute units (f_lambda in cgs units)
fit	float64[4797]	cgs	Best-fit z-channel normalized model flux
abu	float64[4797]	cgs	Best-fit z-channel normalized model flux from the chemical abundance determinations

HDU07

EXTNAME = FIBERMAP

The FIBERMAP targeting table for the objects. The same and in the same order

as in SPTAB.

Required Header Keywords

Required Header Keywords Table

KEY	Example Value	Type	Comment
NAXIS1	341	int	length of dimension 1
NAXIS2	7	int	length of dimension 2

Required Data Table Columns

Name	Type	Units	Description
TARGETID	int64		Unique DESI target ID
COADD_FIBERSTATUS	int32		bitwise-AND of input FIBERSTATUS
TARGET_RA	float64	deg	Target right ascension
TARGET_DEC	float64	deg	Target declination
PMRA	float32	mas yr^-1	proper motion in the +RA direction (already including cos(dec))
PMDEC	float32	mas yr^-1	Proper motion in the +Dec direction
REF_EPOCH	float32	yr	Reference epoch for Gaia/Tycho astrometry. Typically 2015.5 for Gaia
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		Bitmask of allowed observing conditions
RELEASE	int16		Imaging surveys release ID
BRICKNAME	char[8]		Brick name from tractor input
BRICKID	int32		Brick ID from tractor input
BRICK_OBJID	int32		Imaging Surveys OBJID on that brick
MORPHTYPE	char[4]		Imaging Surveys morphological type from Tractor
EBV	float32	mag	Galactic extinction E(B-V) reddening from SFD98
FLUX_G	float32	nanomaggy	Flux in the Legacy Survey g-band (AB)
FLUX_R	float32	nanomaggy	Flux in the Legacy Survey r-band (AB)
FLUX_Z	float32	nanomaggy	Flux in the Legacy Survey z-band (AB)
FLUX_W1	float32	nanomaggy	WISE flux in W1 (AB)
FLUX_W2	float32	nanomaggy	WISE flux in W2 (AB)
FLUX_IVAR_G	float32	nanomaggy^-2	Inverse variance of FLUX_G (AB)
FLUX_IVAR_R	float32	nanomaggy^-2	Inverse variance of FLUX_R (AB)
FLUX_IVAR_Z	float32	nanomaggy^-2	Inverse variance of FLUX_Z (AB)
FLUX_IVAR_W1	float32	nanomaggy^-2	Inverse variance of FLUX_W1 (AB)
FLUX_IVAR_W2	float32	nanomaggy^-2	Inverse variance of FLUX_W2 (AB)
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 from the imaging indicating potential issue or blending
SERSIC	float32		Power-law index for the Sersic profile model (MORPHTYPE=SER)
SHAPE_R	float32	arcsec	Half-light radius of galaxy model (>0)
SHAPE_E1	float32		Ellipticity component 1 of galaxy model for galaxy type MORPHTYPE
SHAPE_E2	float32		Ellipticity component 2 of galaxy model for galaxy type MORPHTYPE
REF_ID	int64		Tyc1*1,000,000+Tyc2*10+Tyc3 for Tycho-2; sourceid for Gaia DR2
REF_CAT	char[2]		Reference catalog source for star: T2 for Tycho-2, G2 for Gaia DR2, L2 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
SV3_DESI_TARGET	int64		DESI (dark time program) target selection bitmask for SV3
SV3_BGS_TARGET	int64		BGS (bright time program) target selection bitmask for SV3
SV3_MWS_TARGET	int64		MWS (bright time program) target selection bitmask for SV3
SV3_SCND_TARGET	int64		Secondary target selection bitmask for SV3
DESI_TARGET	int64		DESI (dark time program) target selection bitmask
BGS_TARGET	int64		BGS (Bright Galaxy Survey) target selection bitmask
MWS_TARGET	int64		Milky Way Survey targeting bits
PLATE_RA	float64	deg	Right Ascension to be used by PlateMaker
PLATE_DEC	float64	deg	Declination 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

HDU08

EXTNAME = SCORES

The table with various quality information about spectra.

Required Header Keywords

Required Header Keywords Table

KEY	Example Value	Type	Comment
NAXIS1	172	int	length of dimension 1
NAXIS2	7	int	length of dimension 2

Required Data Table Columns

Name	Type	Units	Description
TARGETID	int64		Unique DESI target ID
INTEG_COADD_FLUX_B	float32
MEDIAN_COADD_FLUX_B	float32
MEDIAN_COADD_SNR_B	float32
INTEG_COADD_FLUX_R	float32
MEDIAN_COADD_FLUX_R	float32
MEDIAN_COADD_SNR_R	float32
INTEG_COADD_FLUX_Z	float32
MEDIAN_COADD_FLUX_Z	float32
MEDIAN_COADD_SNR_Z	float32
TSNR2_GPBDARK_B	float32
TSNR2_ELG_B	float32		ELG B template (S/N)^2
TSNR2_GPBBRIGHT_B	float32
TSNR2_LYA_B	float32		LYA B template (S/N)^2
TSNR2_BGS_B	float32		BGS B template (S/N)^2
TSNR2_GPBBACKUP_B	float32
TSNR2_QSO_B	float32		QSO B template (S/N)^2
TSNR2_LRG_B	float32		LRG B template (S/N)^2
TSNR2_GPBDARK_R	float32
TSNR2_ELG_R	float32		ELG R template (S/N)^2
TSNR2_GPBBRIGHT_R	float32
TSNR2_LYA_R	float32		LYA R template (S/N)^2
TSNR2_BGS_R	float32		BGS R template (S/N)^2
TSNR2_GPBBACKUP_R	float32
TSNR2_QSO_R	float32		QSO R template (S/N)^2
TSNR2_LRG_R	float32		LRG R template (S/N)^2
TSNR2_GPBDARK_Z	float32
TSNR2_ELG_Z	float32		ELG Z template (S/N)^2
TSNR2_GPBBRIGHT_Z	float32
TSNR2_LYA_Z	float32		LYA Z template (S/N)^2
TSNR2_BGS_Z	float32		BGS Z template (S/N)^2
TSNR2_GPBBACKUP_Z	float32
TSNR2_QSO_Z	float32		QSO Z template (S/N)^2
TSNR2_LRG_Z	float32		LRG Z template (S/N)^2
TSNR2_GPBDARK	float32
TSNR2_ELG	float32		ELG template (S/N)^2 summed over B,R,Z
TSNR2_GPBBRIGHT	float32
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
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

HDU09

EXTNAME = FILTER

Summarize the contents of this HDU.

Required Header Keywords

Required Header Keywords Table

KEY	Example Value	Type	Comment
NAXIS1	32	int	length of dimension 1
NAXIS2	13787	int	length of dimension 2

Required Data Table Columns

Name	Type	Units	Description
Fe	float64		FERRE array of weights used to derive the iron abundance
Ca	float64		FERRE array of weights used to derive the calcium abundance
C	float64		FERRE array of weights used to derive the carbon abundance
Mg	float64		FERRE array of weights used to derive the magnesium abundance

Notes and Examples

https://data.desi.lbl.gov/desi/science/mws/redux/edr/v1/sp_output/220309/healpix/sv3/dark/105/10517/spmod_coadd-sv3-dark-10517.fits