TILEID-too.fits

Summary:

This file contains the Target-of-Opportunity targets covered by the tile disk-footprint.

Naming Convention:

{TILEID}-too.fits, where {TILEID} is the zero-padded, 6-digit TILED.

Regex:

[0-9]{6}-too\.fits

File Type:

FITS, 19 KB

Contents

Number	EXTNAME	Type	Contents
HDU0		IMAGE	Empty HDU
HDU1	TARGETS	BINTABLE	Target-of-Opportunity targets covered by the tile disk-footprint.

FITS Header Units

HDU0

This HDU has no non-standard required keywords.

Empty HDU.

HDU1

EXTNAME = TARGETS

Target-of-Opportunity targets covered by the tile disk-footprint: those are read from the MTL ledgers and desitarget catalogs and provided as input to fiberassign.

Required Header Keywords

Required Header Keywords Table

KEY	Example Value	Type	Comment
NAXIS1	223	int	width of table in bytes
NAXIS2	1	int	number of rows in table
SURVEY	main	str
RESOLVE	T	bool
MASKBITS	T	bool
BACKUP	F	bool
NOSEC	F	bool
DR	None	Unknown

Required Data Table Columns

Name	Type	Units	Description
RA	float64	deg	Barycentric Right Ascension in ICRS
DEC	float64	deg	Barycentric declination in ICRS
PMRA	float64	mas / yr	proper motion in the +RA direction (already including cos(dec))
PMDEC	float64	mas / yr	Proper motion in the +Dec direction
REF_EPOCH	float64	yr	Reference epoch for Gaia/Tycho astrometry. Typically 2015.5 for Gaia
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)
PARALLAX	float32	mas	Reference catalog parallax
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
GAIA_ASTROMETRIC_EXCESS_NOISE	float32		Gaia astrometric excess noise
TARGETID	int64		Unique DESI target ID
DESI_TARGET	int64		DESI (dark time program) target selection bitmask
SCND_TARGET	int64		Target selection bitmask for secondary programs
SCND_ORDER	int32		Number of row for target entry in secondary file (placeholder; needed by fiberassign)
PRIORITY_INIT	int64		Target initial priority from target selection bitmasks and OBSCONDITIONS
SUBPRIORITY	float64		Random subpriority [0-1) to break assignment ties
NUMOBS_INIT	int64		Initial number of observations for target calculated across target selection bitmasks and OBSCONDITIONS
OBSCONDITIONS	int64		Bitmask of allowed observing conditions
CHECKER	char[5]		Initials of researcher who vetted the target
TOO_TYPE	char[5]		Either “TILE” for a special tile or “FIBER” for a fiber-override ToO
TOO_PRIO	char[2]		Either “HI” for a very-high-priority target or “LO” for a very-low-priority target
OCLAYER	char[6]		Either “DARK” for dark-time or “BRIGHT” to observe in either bright- or dark-time
MJD_BEGIN	float64	d	Start of the allowed observing window for this target (Modified Julian Date)
MJD_END	float64	d	End of the allowed observing window for this target (Modified Julian Date)
TOOID	int64		ID for this target assigned by the CHECKER
TIMESTAMP	char[25]	s	UTC/ISO time at which the target state was updated
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
PLATE_REF_EPOCH	float64	yr	Copy of REF_EPOCH to be used by PlateMaker

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.

Some units in this file do not conform to the FITS standard:

• d is incorrectly recorded as day

Such issues can typically be fixed by parsing the unit through astropy after reading in a Table, e.g.:

import astropy.units as u
from astropy.table import Table
objs = Table.read(filename, 1)
u.Unit(str(objs["MJD_END"].unit))