| Summary: | Input spectra to simulate with pixsim. |
|---|---|
| Naming Convention: | simspec-{EXPID}.fits, where {EXPID} is the 8-digit exposure ID. |
| Regex: | simspec-[0-9]{8}\.fits |
| File Type: | FITS, 2 GB |
| Number | EXTNAME | Type | Contents |
|---|---|---|---|
| HDU0 | WAVE | IMAGE | Input wavelength vector |
| HDU1 | FLUX | IMAGE | Input object spectra |
| HDU2 | SKYFLUX | IMAGE | Input sky flux |
| HDU3 | WAVE_B | IMAGE | Input wavelengths b-channel |
| HDU4 | PHOT_B | IMAGE | Input object photons b-channel |
| HDU5 | SKYPHOT_B | IMAGE | Input sky photons b-channel |
| HDU6 | WAVE_R | IMAGE | Input wavelengths r-channel |
| HDU7 | PHOT_R | IMAGE | Input object photons r-channel |
| HDU8 | SKYPHOT_R | IMAGE | Input sky photons r-channel |
| HDU9 | WAVE_Z | IMAGE | Input wavelengths z-channel |
| HDU10 | PHOT_Z | IMAGE | Input object photons z-channel |
| HDU11 | SKYPHOT_Z | IMAGE | Input sky photons z-channel |
| HDU12 | TRUTH | BINTABLE | Truth metadata about the targets |
| HDU13 | FIBERMAP | BINTABLE | Fibermap |
| HDU14 | OBSCONDITIONS | BINTABLE | Observing conditions metadata |
| HDU15 | TRUTH_BGS | BINTABLE | BGS-specific truth metadata |
| HDU16 | TRUTH_ELG | BINTABLE | ELG-specific truth metadata |
| HDU17 | TRUTH_STAR | BINTABLE | STAR-specific truth metadata |
| HDU18 | TRUTH_WD | BINTABLE | WD-specific truth metadata |
EXTNAME = WAVE
Input wavelength vector. Simulation inputs are stored in header cards.
.. collapse:: Required Header Keywords Table
.. rst-class:: keywords
======== =================== ===== ==========================================
KEY Value Type Comment
======== =================== ===== ==========================================
NAXIS1 32001 int Number of wavelength pixels
NIGHT YYYYMMDD str Night of observation
EXPID 0 int DESI exposure ID
TILEID 1 int DESI tile ID
PROGRAM dark str Program name
FLAVOR science str Flavor of observation (arc, flat, science)
TELRA 0.0 float Telescope pointing RA [degrees]
TELDEC 0.0 float Telescope pointing Dec [degrees]
AIRMASS 1.0 float Airmass at middle of exposure
EXPTIME 1000.0 float Exposure time [sec]
SEEING 1.080542206764221 float Seeing FWHM [arcsec]
MOONFRAC 0.4083473802955095 float Moon illumination fraction 0-1; 1=full
MOONALT -4.92578905244666 float Moon altitude [degrees]
MOONSEP 135.3911422523808 float Moon:tile separation angle [degrees]
DATE-OBS 2017-06-15T22:00:00 str Start of exposure
MJD 58925.38986146489 float
SNR2FRAC 0.501188337802887 float
TRANSP 0.9904059171676636 float
SKY 1.0 float
RA 150.73 float
DEC 30.52 float
PASS 4 int
DOSVER SIM str
FEEVER SIM str
BUNIT Angstrom str Wavelength unit
AIRORVAC vac str Vacuum wavelengths
======== =================== ===== ==========================================
Data: FITS image [float64, 32001]
EXTNAME = FLUX
Input object spectra.
.. collapse:: Required Header Keywords Table
.. rst-class:: keywords
======== ============================ ===== ==============
KEY Value Type Comment
======== ============================ ===== ==============
NAXIS1 32001 int
NAXIS2 5000 int
BUNIT 10**-17 erg/(s cm2 Angstrom) str Flux unit
======== ============================ ===== ==============
Data: FITS image [float32, 32001x5000]
EXTNAME = SKYFLUX
Input sky flux.
.. collapse:: Required Header Keywords Table
.. rst-class:: keywords
======== ============================ ===== ==============
KEY Value Type Comment
======== ============================ ===== ==============
NAXIS1 32001 int
NAXIS2 5000 int
BUNIT 10**-17 erg/(s cm2 Angstrom) str Flux unit
======== ============================ ===== ==============
Data: FITS image [float32, 32001x5000]
EXTNAME = WAVE_B
Input wavelengths b-channel [Angstrom].
.. collapse:: Required Header Keywords Table
.. rst-class:: keywords
======== ======== ===== ==================
KEY Value Type Comment
======== ======== ===== ==================
NAXIS1 11901 int
======== ======== ===== ==================
Data: FITS image [float64, 11901]
EXTNAME = PHOT_B
Input object photons b-channel.
.. collapse:: Required Header Keywords Table
.. rst-class:: keywords
======== ======== ===== ==============
KEY Value Type Comment
======== ======== ===== ==============
NAXIS1 11901 int
NAXIS2 5000 int
BUNIT photon str
======== ======== ===== ==============
Data: FITS image [float32, 11901x5000]
EXTNAME = SKYPHOT_B
Input object photons b-channel.
.. collapse:: Required Header Keywords Table
.. rst-class:: keywords
======== ========= ===== ==============
KEY Value Type Comment
======== ========= ===== ==============
NAXIS1 11901 int
NAXIS2 5000 int
BUNIT photon str
======== ========= ===== ==============
Data: FITS image [float32, 11901x5000]
EXTNAME = WAVE_R
Input wavelengths r-channel [Angstrom].
.. collapse:: Required Header Keywords Table
.. rst-class:: keywords
======== ======== ===== ==================
KEY Value Type Comment
======== ======== ===== ==================
NAXIS1 10581 int
======== ======== ===== ==================
Data: FITS image [float64, 10581]
EXTNAME = PHOT_R
Input object photons r-channel.
.. collapse:: Required Header Keywords Table
.. rst-class:: keywords
======== ======== ===== ==============
KEY Value Type Comment
======== ======== ===== ==============
NAXIS1 10581 int
NAXIS2 5000 int
BUNIT photon str
======== ======== ===== ==============
Data: FITS image [float32, 10581x5000]
EXTNAME = SKYPHOT_R
Input object photons r-channel.
.. collapse:: Required Header Keywords Table
.. rst-class:: keywords
======== ========= ===== ==============
KEY Value Type Comment
======== ========= ===== ==============
NAXIS1 10581 int
NAXIS2 5000 int
BUNIT photon str
======== ========= ===== ==============
Data: FITS image [float32, 10581x5000]
EXTNAME = WAVE_Z
Input wavelengths z-channel [Angstrom].
.. collapse:: Required Header Keywords Table
.. rst-class:: keywords
======== ======== ===== ==================
KEY Value Type Comment
======== ======== ===== ==================
NAXIS1 11996 int
======== ======== ===== ==================
Data: FITS image [float64, 11996]
EXTNAME = PHOT_Z
Input object photons z-channel.
.. collapse:: Required Header Keywords Table
.. rst-class:: keywords
======== ======== ===== ==============
KEY Value Type Comment
======== ======== ===== ==============
NAXIS1 11996 int
NAXIS2 5000 int
BUNIT photon str
======== ======== ===== ==============
Data: FITS image [float32, 11996x5000]
EXTNAME = SKYPHOT_Z
Input object photons z-channel.
.. collapse:: Required Header Keywords Table
.. rst-class:: keywords
======== ========= ===== ==============
KEY Value Type Comment
======== ========= ===== ==============
NAXIS1 11996 int
NAXIS2 5000 int
BUNIT photon str
======== ========= ===== ==============
Data: FITS image [float32, 11996x5000]
EXTNAME = TRUTH
.. collapse:: Required Header Keywords Table
.. rst-class:: keywords
====== ============= ==== =====================
KEY Example Value Type Comment
====== ============= ==== =====================
NAXIS1 109 int length of dimension 1
NAXIS2 5000 int length of dimension 2
====== ============= ==== =====================
.. rst-class:: columns
| Name | Type | Units | Description |
|---|---|---|---|
| TARGETID | int64 | Unique DESI target ID | |
| MOCKID | int64 | TODO: description needed | |
| TRUEZ | float32 | TODO: description needed | |
| TRUESPECTYPE | char[10] | TODO: description needed | |
| TEMPLATETYPE | char[10] | TODO: description needed | |
| TEMPLATESUBTYPE | char[10] | TODO: description needed | |
| TEMPLATEID | int32 | TODO: description needed | |
| SEED | int64 | TODO: description needed | |
| MAG | float32 | TODO: description needed | |
| MAGFILTER | char[15] | TODO: description needed | |
| 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_W3 | float32 | TODO: description needed | |
| FLUX_W4 | float32 | TODO: description needed |
EXTNAME = FIBERMAP
Map of which fibers are on which targets. See See :doc:`DESI_SPECTRO_DATA/NIGHT/EXPID/fibermap-EXPID <../../../../DESI_SPECTRO_DATA/NIGHT/EXPID/fibermap-EXPID>`.
.. collapse:: Required Header Keywords Table
.. rst-class:: keywords
======== ======================= ===== ======================================
KEY Example Value Type Comment
======== ======================= ===== ======================================
NAXIS1 334 int length of dimension 1
NAXIS2 5000 int length of dimension 2
NIGHT 20200316 str Night of observation YEARMMDD
EXPID 10 int DESI exposure ID
TILEID 28408 int DESI tile ID
PROGRAM GRAY str program [dark, bright, ...]
FLAVOR science str Flavor [arc, flat, science, zero, ...]
TELRA 150.73 float Telescope pointing RA [degrees]
TELDEC 30.52 float Telescope pointing dec [degrees]
AIRMASS 1.34693655042678 float Airmass at middle of exposure
EXPTIME 757.8536680645208 float Exposure time [sec]
SEEING 1.080542206764221 float Seeing FWHM [arcsec]
MOONFRAC 0.4083473802955095 float Moon illumination fraction 0-1; 1=full
MOONALT -4.92578905244666 float Moon altitude [degrees]
MOONSEP 135.3911422523808 float Moon:tile separation angle [degrees]
DATE-OBS 2020-03-17T09:21:24.031 str Start of exposure
======== ======================= ===== ======================================
.. rst-class:: columns
| Name | Type | Units | Description |
|---|---|---|---|
| TARGETID | int64 | Unique DESI target ID | |
| 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 | |
| SECONDARY_TARGET | int64 | TODO: description needed | |
| TARGET_RA | float64 | deg | Barycentric right ascension in ICRS |
| TARGET_DEC | float64 | deg | Barycentric declination in ICRS |
| TARGET_RA_IVAR | float64 | deg-2 | TODO: description needed |
| TARGET_DEC_IVAR | float64 | deg-2 | TODO: description needed |
| BRICKID | int64 | Brick ID from tractor input | |
| BRICK_OBJID | int64 | Imaging Surveys OBJID on that brick | |
| MORPHTYPE | char[4] | Imaging Surveys morphological type from Tractor | |
| PRIORITY | int32 | Target current priority | |
| SUBPRIORITY | float64 | Random subpriority [0-1) to break assignment ties | |
| REF_ID | int64 | Tyc1*1,000,000+Tyc2*10+Tyc3 for Tycho-2; sourceid for Gaia DR2 |
|
| PMRA | float32 | 10**-3 arcsec yr-1 | proper motion in the +RA direction (already including cos(dec)) |
| PMDEC | float32 | 10**-3 arcsec yr-1 | Proper motion in the +Dec direction |
| REF_EPOCH | float32 | yr | Reference epoch for Gaia/Tycho astrometry. Typically 2015.5 for Gaia |
| PMRA_IVAR | float32 | 10**+6 arcsec-2 yr2 | Inverse variance of PMRA |
| PMDEC_IVAR | float32 | 10**+6 arcsec-2 yr2 | Inverse variance of PMDEC |
| RELEASE | int16 | Imaging surveys release ID | |
| 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 | 1/nanomaggies**2 | Inverse variance of FLUX_G (AB) |
| FLUX_IVAR_R | float32 | 1/nanomaggies**2 | Inverse variance of FLUX_R (AB) |
| FLUX_IVAR_Z | float32 | 1/nanomaggies**2 | Inverse variance of FLUX_Z (AB) |
| FLUX_IVAR_W1 | float32 | 1/nanomaggies**2 | Inverse variance of FLUX_W1 (AB) |
| FLUX_IVAR_W2 | float32 | 1/nanomaggies**2 | Inverse variance of FLUX_W2 (AB) |
| FIBERFLUX_G | float32 | nanomaggies | Predicted g-band flux within a fiber of diameter 1.5 arcsec from this object in 1 arcsec Gaussian seeing |
| FIBERFLUX_R | float32 | nanomaggies | Predicted r-band flux within a fiber of diameter 1.5 arcsec from this object in 1 arcsec Gaussian seeing |
| FIBERFLUX_Z | float32 | nanomaggies | Predicted z-band flux within a fiber of diameter 1.5 arcsec from this object in 1 arcsec Gaussian seeing |
| FIBERFLUX_W1 | float32 | nanomaggies | TODO: description needed |
| FIBERFLUX_W2 | float32 | nanomaggies | TODO: description needed |
| FIBERTOTFLUX_G | float32 | nanomaggies | 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 | nanomaggies | 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 | nanomaggies | Predicted z-band flux within a fiber of diameter 1.5 arcsec from all sources at this location in 1 arcsec Gaussian seeing |
| FIBERTOTFLUX_W1 | float32 | nanomaggies | TODO: description needed |
| FIBERTOTFLUX_W2 | float32 | nanomaggies | TODO: description needed |
| MW_TRANSMISSION_G | float32 | Milky Way dust transmission in LS g-band | |
| MW_TRANSMISSION_R | float32 | Milky Way dust transmission in LS r-band | |
| MW_TRANSMISSION_Z | float32 | Milky Way dust transmission in LS z-band | |
| EBV | float32 | mag | Galactic extinction E(B-V) reddening from SFD98 |
| PHOTSYS | char[1] | 'N' for the MzLS/BASS photometric system, 'S' for DECaLS | |
| OBSCONDITIONS | int32 | Bitmask of allowed observing conditions | |
| NUMOBS_INIT | int64 | Initial number of observations for target calculated across target selection bitmasks and OBSCONDITIONS | |
| PRIORITY_INIT | int64 | Target initial priority from target selection bitmasks and OBSCONDITIONS | |
| NUMOBS_MORE | int32 | Number of additional observations needed | |
| HPXPIXEL | int64 | HEALPixel containing this location at NSIDE=64 in the NESTED scheme | |
| FIBER | int32 | Fiber ID on the CCDs [0-4999] | |
| PETAL_LOC | int32 | Petal location [0-9] | |
| DEVICE_LOC | int32 | Device location on focal plane [0-523] | |
| LOCATION | int32 | Location on the focal plane PETAL_LOC*1000 + DEVICE_LOC | |
| FIBERSTATUS | int32 | Fiber status mask. 0=good | |
| OBJTYPE | char[3] | Object type: TGT, SKY, NON, BAD | |
| LAMBDA_REF | float32 | Angstrom | Requested wavelength at which targets should be centered on fibers |
| FIBERASSIGN_X | float32 | mm | Fiberassign expected CS5 X location on focal plane |
| FIBERASSIGN_Y | float32 | mm | Fiberassign expected CS5 Y location on focal plane |
| FA_TARGET | int64 | Targeting bit internally used by fiberassign (linked with FA_TYPE) | |
| FA_TYPE | byte | Fiberassign internal target type (science, standard, sky, safe, suppsky) | |
| NUMTARGET | int16 | Total number of targets that this positioner covered | |
| FIBER_RA | float64 | deg | RA of actual fiber position |
| FIBER_DEC | float64 | deg | DEC of actual fiber position |
| FIBER_RA_IVAR | float32 | deg-2 | TODO: description needed |
| FIBER_DEC_IVAR | float32 | deg-2 | TODO: description needed |
| PLATEMAKER_X | float32 | mm | TODO: description needed |
| PLATEMAKER_Y | float32 | mm | TODO: description needed |
| PLATEMAKER_RA | float32 | deg | TODO: description needed |
| PLATEMAKER_DEC | float32 | deg | TODO: description needed |
| NUM_ITER | int32 | Number of positioner iterations | |
| SPECTROID | int32 | Hardware ID of spectrograph (not used) | |
| BRICKNAME | char[8] | Brick name from tractor input | |
| LAMBDAREF | float64 | TODO: description needed | |
| DELTA_X | float64 | mm | CS5 X requested minus actual position |
| DELTA_Y | float64 | mm | CS5 Y requested minus actual position |
EXTNAME = OBSCONDITIONS
Table with a single row defining the observing conditions for this exposure, e.g. SEEING, AIRMASS, lunar conditions.
.. collapse:: Required Header Keywords Table
.. rst-class:: keywords
====== ============= ==== =====================
KEY Example Value Type Comment
====== ============= ==== =====================
NAXIS1 115 int length of dimension 1
NAXIS2 1 int length of dimension 2
====== ============= ==== =====================
.. rst-class:: columns
| Name | Type | Units | Description |
|---|---|---|---|
| EXPID | int32 | Exposure ID | |
| MJD | float64 | d | Modified Julian Date |
| EXPTIME | float32 | s | Exposure time |
| TILEID | int32 | Tile ID | |
| SNR2FRAC | float32 | TODO: description needed | |
| AIRMASS | float32 | Airmass | |
| SEEING | float32 | arcsec | Atmospheric seeing FWHM |
| TRANSP | float32 | Transparency [0-1]; 0=no photons | |
| SKY | float32 | TODO: description needed | |
| PROGRAM | char[6] | DESI program name (e.g. DARK/GRAY/BRIGHT) | |
| NIGHT | char[8] | Night 'YEARMMDD' | |
| FLAVOR | char[7] | Exposure flavor (e.g. science or calib) | |
| MOONFRAC | float64 | Moon illumination fraction [0-1]; 1=full moon | |
| MOONALT | float64 | deg | Moon altitude |
| MOONSEP | float64 | deg | Separation angle between moon and center of tile |
| RA | float64 | deg | Right ascension |
| DEC | float64 | deg | Declination |
| PASS | int16 | tiling pass number |
TODO: define if AIRMASS etc. are at middle of exposure, averaged, etc.
EXTNAME = TRUTH_BGS
Truth metadata that are specific to BGS targets.
.. collapse:: Required Header Keywords Table
.. rst-class:: keywords
====== ============= ==== =====================
KEY Example Value Type Comment
====== ============= ==== =====================
NAXIS1 56 int length of dimension 1
NAXIS2 262 int length of dimension 2
====== ============= ==== =====================
.. rst-class:: columns
| Name | Type | Units | Description |
|---|---|---|---|
| TARGETID | int64 | Unique DESI target ID | |
| OIIFLUX | float32 | TODO: description needed | |
| HBETAFLUX | float32 | TODO: description needed | |
| EWOII | float32 | TODO: description needed | |
| EWHBETA | float32 | TODO: description needed | |
| D4000 | float32 | TODO: description needed | |
| VDISP | float32 | TODO: description needed | |
| OIIDOUBLET | float32 | TODO: description needed | |
| OIIIHBETA | float32 | TODO: description needed | |
| OIIHBETA | float32 | TODO: description needed | |
| NIIHBETA | float32 | TODO: description needed | |
| SIIHBETA | float32 | TODO: description needed | |
| TRUEZ_NORSD | float32 | TODO: description needed |
EXTNAME = TRUTH_ELG
Truth metadata that are specific to ELG targets.
.. collapse:: Required Header Keywords Table
.. rst-class:: keywords
====== ============= ==== =====================
KEY Example Value Type Comment
====== ============= ==== =====================
NAXIS1 56 int length of dimension 1
NAXIS2 4225 int length of dimension 2
====== ============= ==== =====================
.. rst-class:: columns
| Name | Type | Units | Description |
|---|---|---|---|
| TARGETID | int64 | Unique DESI target ID | |
| OIIFLUX | float32 | TODO: description needed | |
| HBETAFLUX | float32 | TODO: description needed | |
| EWOII | float32 | TODO: description needed | |
| EWHBETA | float32 | TODO: description needed | |
| D4000 | float32 | TODO: description needed | |
| VDISP | float32 | TODO: description needed | |
| OIIDOUBLET | float32 | TODO: description needed | |
| OIIIHBETA | float32 | TODO: description needed | |
| OIIHBETA | float32 | TODO: description needed | |
| NIIHBETA | float32 | TODO: description needed | |
| SIIHBETA | float32 | TODO: description needed | |
| TRUEZ_NORSD | float32 | TODO: description needed |
EXTNAME = TRUTH_STAR
Truth metadata that are specific to STAR targets.
.. collapse:: Required Header Keywords Table
.. rst-class:: keywords
====== ============= ==== =====================
KEY Example Value Type Comment
====== ============= ==== =====================
NAXIS1 20 int length of dimension 1
NAXIS2 106 int length of dimension 2
====== ============= ==== =====================
.. rst-class:: columns
| Name | Type | Units | Description |
|---|---|---|---|
| TARGETID | int64 | Unique DESI target ID | |
| TEFF | float32 | TODO: description needed | |
| LOGG | float32 | TODO: description needed | |
| FEH | float32 | TODO: description needed |
EXTNAME = TRUTH_WD
Truth metadata that are specific to White Dwarf targets.
.. collapse:: Required Header Keywords Table
.. rst-class:: keywords
====== ============= ==== =====================
KEY Example Value Type Comment
====== ============= ==== =====================
NAXIS1 16 int length of dimension 1
NAXIS2 1 int length of dimension 2
====== ============= ==== =====================
.. rst-class:: columns
| Name | Type | Units | Description |
|---|---|---|---|
| TARGETID | int64 | Unique DESI target ID | |
| TEFF | float32 | TODO: description needed | |
| LOGG | float32 | TODO: description needed |