QSO_cat_cumulative

Summary:

This contains the information on quasar automatically identified from DESI spectra coadded for all observations of the relevant tiles. Data appearing here is considered a successful quasar redshift by the LSS pipeline.

Naming Convention:

QSO_cat_{SPECPROD}_cumulative_{VERSION}.fits.

Regex:

QSO_cat_[a-z]+_cumulative_v[0-9]\.fits

File Type:

FITS, 778 MB

Contents

Number	EXTNAME	Type	Contents
HDU0		IMAGE	Empty
HDU1	QSO_CAT	BINTABLE	Quasar Catalog

FITS Header Units

HDU0

This HDU has no non-standard required keywords.

Empty HDU.

HDU1

EXTNAME = QSO_CAT

This HDU contains all of the information on the identified quasars. Further information could be obtained via a match to other files that contain the columns TARGETID and TILEID.

Required Header Keywords

Required Header Keywords Table

KEY	Example Value	Type	Comment
NAXIS1	384	int	width of table in bytes
NAXIS2	2182309	int	number of rows in table
DESIDR	dr1	str	DESI Data Release

Required Data Table Columns

Name	Type	Units	Description
TARGETID	int64		Unique DESI target ID
Z	float64		Redshift measured by Redrock
ZERR	float64		Redshift error from redrock
ZWARN	int64		Redshift warning bitmask from Redrock
LOCATION	int64		Location on the focal plane PETAL_LOC*1000 + DEVICE_LOC
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
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)
MW_TRANSMISSION_G	float64		Milky Way dust transmission in LS g-band
MW_TRANSMISSION_R	float64		Milky Way dust transmission in LS r-band
MW_TRANSMISSION_Z	float64		Milky Way dust transmission in LS z-band
MW_TRANSMISSION_W1	float64		Milky Way dust transmission in WISE W1
MW_TRANSMISSION_W2	float64		Milky Way dust transmission in WISE W2
PROBA_RF	float64		Probability of being a quasar generated by the quasar Random Forest targeting algorithm.
FLUX_IVAR_W2	float32	nanomaggy^-2	Inverse variance of FLUX_W2 (AB)
MASKBITS	int16		Bitwise mask from the imaging indicating potential issue or blending
CMX_TARGET	int64		Target selection bitmask for commissioning
DESI_TARGET	int64		DESI (dark time program) target selection bitmask
COADD_NUMEXP	int16		Number of exposures in coadd
COADD_EXPTIME	float32	s	Summed exposure time for coadd
SV1_DESI_TARGET	int64		DESI (dark time program) target selection bitmask for SV1
SV2_DESI_TARGET	int64		DESI (dark time program) target selection bitmask for SV2
SV3_DESI_TARGET	int64		DESI (dark time program) target selection bitmask for SV3
SV1_SCND_TARGET	int64		Secondary target selection bitmask for SV1
SV2_SCND_TARGET	int64		Secondary target selection bitmask for SV2
SV3_SCND_TARGET	int64		Secondary target selection bitmask for SV3
SCND_TARGET	int64		Target selection bitmask for secondary programs
TSNR2_LYA	float32		LYA template (S/N)^2 summed over B,R,Z
TSNR2_QSO	float32		QSO template (S/N)^2 summed over B,R,Z
DELTA_CHI2_MGII	float32		Difference of chi2 between redrock fit and MgII fitter over the lambda interval considered during the fit
A_MGII	float32		Fitted parameter A (amplitude) by MgII fitter
SIGMA_MGII	float32	Angstrom	Fitted parameter SIGMA (linewidth) by MgII fitter (in angstrom?)
B_MGII	float32		Fitted parameter B (constant) by MgII fitter
VAR_A_MGII	float32		Variance of MgII fit amplitude parameter A
VAR_SIGMA_MGII	float32		Variance of MgII fit width parameter sigma
VAR_B_MGII	float32		Variance of MgII fit offset parameter B
Z_RR	float32		Redshift collected from redrock file
Z_QN	float32		Redshift measured by QuasarNET using line with highest confidence
C_LYA	float32		Confidence for LyA line, i.e. ~probability to be a QSO
C_CIV	float32		Confidence for CIV line
C_CIII	float32		Confidence for CIII line
C_MgII	float32		Confidence for MgII line
C_Hbeta	float32		Confidence for Hbeta line
C_Halpha	float32		Confidence for Halpha line
Z_LYA	float32		Redshift estimated by QuasarNET with LyA line
Z_CIV	float32		Redshift estimated by QuasarNET with CIV line
Z_CIII	float32		Redshift estimated by QuasarNET with CIII line
Z_MgII	float32		Redshift estimated by QuasarNET with MgII line
Z_Hbeta	float32		Redshift estimated by QuasarNET with Hbeta line
Z_Halpha	float32		Redshift estimated by QuasarNET with Halpha line
QSO_MASKBITS	int32		QSO Bitwise mask from the imaging indicating potential issue or blending
TILEID	int64		Unique DESI tile ID
LASTNIGHT	int64		Final night of observation included in a series of coadds
PETAL_LOC	int64		Petal location [0-9]
SURVEY	char[7]		Survey name: cmx, sv1, sv2, sv3, main
PROGRAM	char[6]		DESI program type - BRIGHT, DARK, BACKUP, OTHER
MORPHTYPE	char[3]		Imaging Surveys morphological type from Tractor
SPECTYPE	char[6]		Spectral type of Redrock best fit template (e.g. GALAXY, QSO, STAR)

Notes and Examples

As of DR1, the selection criteria are the same as described in Chaussidon et al. (2023)