thru

Summary:

Throughput data file.

Naming Convention:

thru-{ARM}.fits, where {ARM} is ‘b’, ‘r’, ‘z’.

Regex:

thru-[brz]\.fits

File Type:

FITS, 1 MB

Contents

Number	EXTNAME	Type	Contents
HDU0	PRIMARY	IMAGE	Empty
HDU1	THROUGHPUT	BINTABLE	Throughput model
HDU2	FIBERINPUT	BINTABLE	Geometric loss at fiber input

FITS Header Units

HDU0

EXTNAME = PRIMARY

This HDU has no non-standard required keywords.

Empty HDU.

HDU1

EXTNAME = THROUGHPUT

Throughput model.

Required Header Keywords

KEY	Example Value	Type	Comment
NAXIS1	32	int	length of dimension 1
NAXIS2	24651	int	length of dimension 2
EXPTIME	1000.0	float	default exposure time [sec]
GEOMAREA	86787.09421000001	float	geometric area of mirror - obscurations
FIBERDIA	1.52	float	average fiber diameter [arcsec]
WAVEMIN	3533	int	Minimum wavelength [Angstroms]
WAVEMAX	5998	int	Maximum wavelength [Angstroms]
EXTNAME	THROUGHPUT	str	extension name

Required Data Table Columns

Name	Type	Units	Description
wavelength	float64	Angstrom	Wavelengths
throughput	float64		Throughput losses not due to atmosphere or fiber inputs
extinction	float64		Atmospheric extinction
fiberinput	float64		DEPRECATED; fiber input losses (point-source?)

HDU2

EXTNAME = FIBERINPUT

Typical fiber input geometric throughput for various object types. 0 = no transmission; 1 = all light makes it into the fibers.

Required Header Keywords

KEY	Example Value	Type	Comment
NAXIS1	40	int	length of dimension 1
NAXIS2	24651	int	length of dimension 2
EXTNAME	FIBERINPUT	str	extension name

Required Data Table Columns

Name	Type	Units	Description
wavelength	float64	Angstrom	Wavelengths at which loss is modeled
elg	float64		throughput for typical ELG
lrg	float64		throughput for typical LRG
star	float64		throughput for typical point source
sky	float64		throughput for uniform source