Fastphot Data Model

Summary:

Broadband photometric fitting results.

Naming Convention:

fastphot-SURVEY-PROGRAM-HEALPIX.fits, where SURVEY is the survey name (e.g., main or sv3), PROGRAM is the program name (e.g., bright or dark), and HEALPIX is the healpixel number.

Regex:

fastphot-(cmx|main|special|sv1|sv2|sv3)-(backup|bright|dark|other)-[0-9]+\.fits

File Type:

FITS

Contents

Number	EXTNAME	Type	Contents
HDU00	PRIMARY	IMAGE	Keywords only.
HDU01	FASTPHOT	BINTABLE	Table with photometric fitting results.
HDU02	METADATA	BINTABLE	Table with sample metadata.

FITS Header Units

HDU00

EXTNAME = PRIMARY

Required Header Keywords

Required Header Keywords Table

KEY	Example Value	Type	Comment
SPECPROD	iron	str	Spectroscopic production name
COADDTYP	healpix	str	Type of spectral coadd (healpix,cumulative,pernight,perexp)
CHECKSUM	UKXHaIWHUIWHaIWH	str	HDU checksum updated 2022-08-02T00:24:13
DATASUM	0	str	data unit checksum updated 2022-08-02T00:24:13

Empty HDU.

HDU01

EXTNAME = FASTPHOT

Broadband photometric fitting results.

Required Header Keywords

Required Header Keywords Table

KEY	Example Value	Type	Comment
NAXIS1	335	int	length of dimension 1
NAXIS2	338	int	length of dimension 2
CHECKSUM	PI3dSH0aPH0aPH0a	str	HDU checksum updated 2022-08-02T00:24:13
DATASUM	72956540	str	data unit checksum updated 2022-08-02T00:24:13

Required Data Table Columns

Name	Type	Units	Description
TARGETID	int64		Unique target ID.
SURVEY [1]	bytes3		Survey name.
PROGRAM [1]	bytes6		Program name.
HEALPIX [1]	int32		Healpixel number.
TILEID [2]	int32		Tile ID number.
NIGHT [2]	int32		Night of observation.
FIBER [2]	int32		Fiber number.
EXPID [3]	int32		Exposure ID number.
Z	float64		Stellar continuum redshift.
COEFF	float32[168]		Continuum coefficients.
RCHI2_PHOT	float32		Reduced chi-squared of the fit to the broadband photometry.
VDISP	float32	km / s	Stellar velocity dispersion.
AV	float32	mag	Attenuation of the integrated stellar population.
AGE	float32	Gyr	Light-weighted age.
ZZSUN	float32		Logarithmic stellar metallicity relative to solar.
LOGMSTAR	float32	Msun	Logarithmic stellar mass (h=1.0, Chabrier+2003 initial mass function).
SFR	float32	Msun / yr	Instantaneous star formation rate (h=1.0, Chabrier+2003 initial mass function).
DN4000_MODEL	float32		Narrow 4000-A break index (from Balogh et al. 1999) measured from the best-fitting continuum model.
FLUX_SYNTH_PHOTMODEL_G	float32	nmgy	g-band flux synthesized from the best-fitting photometric continuum model.
FLUX_SYNTH_PHOTMODEL_R	float32	nmgy	r-band flux synthesized from the best-fitting photometric continuum model.
FLUX_SYNTH_PHOTMODEL_Z	float32	nmgy	z-band flux synthesized from the best-fitting photometric continuum model.
FLUX_SYNTH_PHOTMODEL_W1	float32	nmgy	W1-band flux synthesized from the best-fitting photometric continuum model.
FLUX_SYNTH_PHOTMODEL_W2	float32	nmgy	W2-band flux synthesized from the best-fitting photometric continuum model.
FLUX_SYNTH_PHOTMODEL_W3	float32	nmgy	W3-band flux synthesized from the best-fitting photometric continuum model.
FLUX_SYNTH_PHOTMODEL_W4	float32	nmgy	W4-band flux synthesized from the best-fitting photometric continuum model.
ABSMAG10_DECAM_G [4]	float32	mag	Absolute magnitude in DECam g-band band-shifted to z=1.0 assuming h=1.0.
ABSMAG10_IVAR_DECAM_G	float32	1 / mag2	Inverse variance corresponding to ABSMAG10_DECAM_G.
KCORR10_DECAM_G	float32	mag	K-correction used to derive ABSMAG10_DECAM_G band-shifted to z=1.0.
ABSMAG10_DECAM_R [4]	float32	mag	Absolute magnitude in DECam r-band band-shifted to z=1.0 assuming h=1.0.
ABSMAG10_IVAR_DECAM_R	float32	1 / mag2	Inverse variance corresponding to ABSMAG10_DECAM_R.
KCORR10_DECAM_R	float32	mag	K-correction used to derive ABSMAG10_DECAM_R band-shifted to z=1.0.
ABSMAG10_DECAM_Z [4]	float32	mag	Absolute magnitude in DECam z-band band-shifted to z=1.0 assuming h=1.0.
ABSMAG10_IVAR_DECAM_Z	float32	1 / mag2	Inverse variance corresponding to ABSMAG10_DECAM_Z.
KCORR10_DECAM_Z	float32	mag	K-correction used to derive ABSMAG10_DECAM_Z band-shifted to z=1.0.
ABSMAG00_U [4]	float32	mag	Absolute magnitude in Johnson/Cousins U-band band-shifted to z=0.0 assuming h=1.0.
ABSMAG00_IVAR_U	float32	1 / mag2	Inverse variance corresponding to ABSMAG_U.
KCORR00_U	float32	mag	K-correction used to derive ABSMAG_U band-shifted to z=0.0.
ABSMAG00_B [4]	float32	mag	Like ABSMAG_U but for Johnson/Cousins B-band.
ABSMAG00_IVAR_B	float32	1 / mag2	Like ABSMAG_IVAR_U but for Johnson/Cousins B-band.
KCORR00_B	float32	mag	Like KCORR_U but for Johnson/Cousins B-band.
ABSMAG00_V [4]	float32	mag	Like ABSMAG_U but for Johnson/Cousins V-band.
ABSMAG00_IVAR_V	float32	1 / mag2	Like ABSMAG_IVAR_U but for Johnson/Cousins V-band.
KCORR00_V	float32	mag	Like KCORR_U but for Johnson/Cousins V-band.
ABSMAG01_SDSS_U [4]	float32	mag	Absolute magnitude in SDSS u-band band-shifted to z=0.1 assuming h=1.0.
ABSMAG01_IVAR_SDSS_U	float32	1 / mag2	Inverse variance corresponding to ABSMAG_SDSS_U.
KCORR01_SDSS_U	float32	mag	K-correction used to derive ABSMAG_SDSS_U band-shifted to z=0.1.
ABSMAG01_SDSS_G [4]	float32	mag	Like ABSMAG_SDSS_U but for SDSS g-band.
ABSMAG01_IVAR_SDSS_G	float32	1 / mag2	Like ABSMAG_IVAR_SDSS_U but for SDSS g-band.
KCORR01_SDSS_G	float32	mag	Like KCORR_SDSS_U but for SDSS g-band.
ABSMAG01_SDSS_R [4]	float32	mag	Like ABSMAG_SDSS_U but for SDSS r-band.
ABSMAG01_IVAR_SDSS_R	float32	1 / mag2	Like ABSMAG_IVAR_SDSS_U but for SDSS r-band.
KCORR01_SDSS_R	float32	mag	Like KCORR_SDSS_U but for SDSS r-band.
ABSMAG01_SDSS_I [4]	float32	mag	Like ABSMAG_SDSS_U but for SDSS i-band.
ABSMAG01_IVAR_SDSS_I	float32	1 / mag2	Like ABSMAG_IVAR_SDSS_U but for SDSS i-band.
KCORR01_SDSS_I	float32	mag	Like KCORR_SDSS_U but for SDSS i-band.
ABSMAG01_SDSS_Z [4]	float32	mag	Like ABSMAG_SDSS_U but for SDSS z-band.
ABSMAG01_IVAR_SDSS_Z	float32	1 / mag2	Like ABSMAG_IVAR_SDSS_U but for SDSS z-band.
KCORR01_SDSS_Z	float32	mag	Like KCORR_SDSS_U but for SDSS z-band.
ABSMAG00_W1 [4]	float32	mag	Absolute magnitude in WISE W1-band band-shifted to z=0.0 assuming h=1.0.
ABSMAG00_IVAR_W1	float32	1 / mag2	Inverse variance corresponding to ABSMAG_W1.
KCORR00_W1	float32	mag	K-correction used to derive ABSMAG_W1 band-shifted to z=0.0.
LOGLNU_1500	float32	1e-28 erg / (s Hz)	Monochromatic luminosity at 1500 A in the rest-frame.
LOGLNU_2800	float32	1e-28 erg / (s Hz)	Monochromatic luminosity at 2800 A in the rest-frame.
LOGL_1450	float32	1e+10 Lsun	Integrated luminosity at 1450 A in the rest-frame.
LOGL_1700	float32	1e+10 Lsun	Integrated luminosity at 1700 A in the rest-frame.
LOGL_3000	float32	1e+10 Lsun	Integrated luminosity at 3000 A in the rest-frame.
LOGL_5100	float32	1e+10 Lsun	Integrated luminosity at 5100 A in the rest-frame.
FLYA_1215_CONT	float32	1e-17 erg / (Angstrom cm2 s)	Continuum flux at 1215.67 A in the rest-frame.
FOII_3727_CONT	float32	1e-17 erg / (Angstrom cm2 s)	Continuum flux at 3728.483 A in the rest-frame.
FHBETA_CONT	float32	1e-17 erg / (Angstrom cm2 s)	Continuum flux at 4862.683 A in the rest-frame.
FOIII_5007_CONT	float32	1e-17 erg / (Angstrom cm2 s)	Continuum flux at 5008.239 A in the rest-frame.
FHALPHA_CONT	float32	1e-17 erg / (Angstrom cm2 s)	Continuum flux at 6564.613 A in the rest-frame.

HDU02

EXTNAME = METADATA

Metadata associated with each objected fitted.

Required Header Keywords

Required Header Keywords Table

KEY	Example Value	Type	Comment
NAXIS1	339	int	length of dimension 1
NAXIS2	338	int	length of dimension 2
CHECKSUM	iFX6iFW6iFW6iFW6	str	HDU checksum updated 2022-08-02T00:24:13
DATASUM	1759692941	str	data unit checksum updated 2022-08-02T00:24:13

Required Data Table Columns

Name	Type	Units	Description
TARGETID	int64		Unique target ID.
SURVEY [1]	bytes3		Survey name.
PROGRAM [1]	bytes6		Program name.
HEALPIX [1]	int32		Healpixel number.
TILEID [2]	int32		Tile ID number.
FIBER [2]	int32		Fiber number.
NIGHT [2]	int32		Night of observation.
EXPID [3]	int32		Exposure ID number.
TILEID_LIST	str5		List of tile IDs that went into healpix coadd.
RA	float64	deg	Right ascension from target catalog.
DEC	float64	deg	Declination from target catalog.
COADD_FIBERSTATUS	int64		Fiber status bit.
CMX_TARGET [4]	int64		Commissioning (CMX) targeting bit.
DESI_TARGET	int64		DESI targeting bit.
BGS_TARGET	int64		BGS targeting bit.
MWS_TARGET	int64		MWS targeting bit.
SCND_TARGET	int64		Secondary target targeting bit.
SV1_DESI_TARGET [5]	int64		SV1 DESI targeting bit.
SV1_BGS_TARGET [5]	int64		SV1 BGS targeting bit.
SV1_MWS_TARGET [5]	int64		SV1 MWS targeting bit.
SV2_DESI_TARGET [5]	int64		SV2 DESI targeting bit.
SV2_BGS_TARGET [5]	int64		SV2 BGS targeting bit.
SV2_MWS_TARGET [5]	int64		SV2 MWS targeting bit.
SV3_DESI_TARGET [5]	int64		SV3 DESI targeting bit.
SV3_BGS_TARGET [5]	int64		SV3 BGS targeting bit.
SV3_MWS_TARGET [5]	int64		SV3 MWS targeting bit.
SV1_SCND_TARGET [5]	int64		SV1 secondary targeting bit.
SV2_SCND_TARGET [5]	int64		SV2 secondary targeting bit.
SV3_SCND_TARGET [5]	int64		SV3 secondary targeting bit.
Z	float64		Redshift based on Redrock or QuasarNet (for QSO targets only).
ZWARN	int8		Redrock zwarning bit.
DELTACHI2	float64		Redrock delta-chi-squared.
SPECTYPE	str6		Redrock spectral classification.
Z_RR	float64		Redrock redshift.
TSNR2_BGS	float32		Template signal-to-noise ratio squared for BGS targets.
TSNR2_LRG	float32		Template signal-to-noise ratio squared for LRG targets.
TSNR2_ELG	float32		Template signal-to-noise ratio squared for ELG targets.
TSNR2_QSO	float32		Template signal-to-noise ratio squared for QSO targets.
TSNR2_LYA	float32		Template signal-to-noise ratio squared for LYA targets.
PHOTSYS	bytes1		Photometric system (N or S).
LS_ID	int64		Unique Legacy Surveys identification number.
FIBERFLUX_G	float32	nmgy	Fiber g-band flux corrected for Galactic extinction.
FIBERFLUX_R	float32	nmgy	Fiber r-band flux corrected for Galactic extinction.
FIBERFLUX_Z	float32	nmgy	Fiber z-band flux corrected for Galactic extinction.
FIBERTOTFLUX_G	float32	nmgy	Fibertot g-band flux corrected for Galactic extinction.
FIBERTOTFLUX_R	float32	nmgy	Fibertot r-band flux corrected for Galactic extinction.
FIBERTOTFLUX_Z	float32	nmgy	Fibertot z-band flux corrected for Galactic extinction.
FLUX_G	float32	nmgy	Total g-band flux corrected for Galactic extinction.
FLUX_R	float32	nmgy	Total r-band flux corrected for Galactic extinction.
FLUX_Z	float32	nmgy	Total z-band flux corrected for Galactic extinction.
FLUX_W1	float32	nmgy	Total W1-band flux corrected for Galactic extinction.
FLUX_W2	float32	nmgy	Total W2-band flux corrected for Galactic extinction.
FLUX_W3	float32	nmgy	Total W3-band flux corrected for Galactic extinction.
FLUX_W4	float32	nmgy	Total W4-band flux corrected for Galactic extinction.
FLUX_IVAR_G	float32	1 / nmgy2	Inverse variance of FLUX_G corrected for Galactic extinction.
FLUX_IVAR_R	float32	1 / nmgy2	Inverse variance of FLUX_R corrected for Galactic extinction.
FLUX_IVAR_Z	float32	1 / nmgy2	Inverse variance of FLUX_Z corrected for Galactic extinction.
FLUX_IVAR_W1	float32	1 / nmgy2	Inverse variance of FLUX_W1 corrected for Galactic extinction.
FLUX_IVAR_W2	float32	1 / nmgy2	Inverse variance of FLUX_W2 corrected for Galactic extinction.
FLUX_IVAR_W3	float32	1 / nmgy2	Inverse variance of FLUX_W3 corrected for Galactic extinction.
FLUX_IVAR_W4	float32	1 / nmgy2	Inverse variance of FLUX_W4 corrected for Galactic extinction.
EBV	float32	mag	Milky Way foreground dust reddening.
MW_TRANSMISSION_G	float32		Milky Way foreground dust transmission factor [0-1] in the g-band.
MW_TRANSMISSION_R	float32		Milky Way foreground dust transmission factor [0-1] in the r-band.
MW_TRANSMISSION_Z	float32		Milky Way foreground dust transmission factor [0-1] in the z-band.
MW_TRANSMISSION_W1	float32		Milky Way foreground dust transmission factor [0-1] in the W1-band.
MW_TRANSMISSION_W2	float32		Milky Way foreground dust transmission factor [0-1] in the W2-band.
MW_TRANSMISSION_W3	float32		Milky Way foreground dust transmission factor [0-1] in the W3-band.
MW_TRANSMISSION_W4	float32		Milky Way foreground dust transmission factor [0-1] in the W4-band.

[1] (1,2,3,4,5,6)

Column only present when fitting healpix coadds.

[2] (1,2,3,4,5,6)

Column only present when fitting cumulative, per-night, or per-expopsure tile-based coadds.

[3] (1,2)

Column only present when fitting per-exposure tile-based coadds.

[4] (1,2,3,4,5,6,7,8,9,10,11,12,13)

Only observed photometry with a minimum signal-to-noise ratio of two is used to compute K-corrections. Absolute magnitudes are estimated using from the (S/N>2) observed-frame bandpass nearest in wavelength to the desired band-shifted rest-frame bandpass. If no observed-frame photometry is available, then the absolute magnitude is synthesized from the best-fitting model and the corresponding inverse variance is set to zero.

[5] (1,2,3,4,5,6,7,8,9,10,11,12)

Column only present in Commissioning and Survey Validation spectroscopic observations.