Data model: specObj

General Description
This file contains the list of all spectra for a given data release, with associated parameters from the 2D and 1D pipelines for each.
Naming Convention
specObj-dr[0-9]+\.fits, where [0-9]+ is the release number (8, 9, 10, ...).
Approximate Size
2 Gbytes
File Type
FITS
Read by Products
sas
Written by Products
sas

HDU0: header HDU for table

Required Header Keywords
KEYValueTypeComment
SIMPLETboolConforms to FITS standard
BITPIX16int16 bit floating point (dummy value)
NAXIS0int0 (no data in this HDU)
EXTENDTboolExtensions may be present
SAS_VERSstrVersion of sas used to create file
TREE_VERstrVersion of tree used to create file

HDU1: table with catalog

Required Header Keywords
KEYValueTypeComment
XTENSIONBINTABLEstrTable Extension
TFIELDS127intNumber of columns in table
Required Columns
NameTypeComment
SURVEYstrSurvey that this object is part of
INSTRUMENTstrInstrument that this spectrum was observed with (SDSS or BOSS)
CHUNKstrName of tiling chunk that this spectrum was tiled in (boss1, boss2, etc), important for tracking large-scale structure samples
PROGRAMNAMEstrProgram within each survey that the plate was part of
PLATERUNstrDrilling run that this plate was drilled in
PLATEQUALITYstrFinal quality of plate this spectrum came from ("good", "marginal" or "bad")
PLATESN2float32Overall signal-to-noise-squared measure for plate (only for SDSS spectrograph plates)
DEREDSN2float32Dereddened overall signal-to-noise-squared measure for plate (only for BOSS spectrograph plates)
LAMBDA_EFFfloat32Effective wavelength drilling position was optimized for (Angstroms)
BLUE_FIBERint32Set to 1 if this was requested to be a "blue fiber" target, 0 if it was a "red fiber" (in BOSS high redshift LRGs are requested to be on red fibers)
ZOFFSETfloat32Washer thickness used (for backstopping BOSS quasar targets, so they are closer to 4000 Angstrom focal plan (microns)
SNTURNOFFfloat32Signal to noise measure for MS turnoff stars on plate (-9999 if not appropriate)
NTURNOFFint32Number of stars used for SNTURNOFF determination
SPECPRIMARYint1Set to 1 for primary observation of object, 0 otherwise
SPECSDSSint1Set to 1 for primary SDSS spectrograph observation of object, 0 otherwise
SPECLEGACYint1Set to 1 for primary SDSS Legacy program observation of object, 0 otherwise
SPECSEGUEint1Set to 1 for primary SDSS SEGUE program observation of object (including SEGUE-1 and SEGUE-2), 0 otherwise
SPECSEGUE1int1Set to 1 for primary SDSS SEGUE-1 program observation of object, 0 otherwise
SPECSEGUE2int1Set to 1 for primary SDSS SEGUE-2 program observation of object, 0 otherwise
SPECBOSSint1Set to 1 for primary BOSS spectrograph observation of object, 0 otherwise
BOSS_SPECOBJ_IDint32Identification number internal to BOSS for SPECBOSS=1 objects
SPECOBJIDstrUnique database ID based on PLATE, MJD, FIBERID, RUN2D (same as SkyServer version)
FLUXOBJIDstrUnique database ID of flux-based photometric match based on RUN, RERUN, CAMCOl, FIELD, ID (same as SkyServer version)
BESTOBJIDstrUnique database ID of (recommended) position-based photometric match based on RUN, RERUN, CAMCOl, FIELD, ID (same as SkyServer version)
TARGETOBJIDstrUnique database ID of targeting object based on RUN, RERUN, CAMCOl, FIELD, ID (same as SkyServer version)
PLATEIDstrUnique database ID of plate based on PLATE, MJD, RUN2D (same as SkyServer version)
NSPECOBSint16Number of spectroscopic observations of this source
FIRSTRELEASEstrName of first release this PLATE, MJD, FIBERID, RUN2D was associated with
RUN2DstrSpectroscopic 2D reduction (extraction of spectra) name
RUN1DstrSpectroscopic 1D reduction (redshift and classification) name
DESIGNIDint32Design identification number for plate
CXfloat64Position of object on J2000 unit sphere
CYfloat64Position of object on J2000 unit sphere
CZfloat64Position of object on J2000 unit sphere
XFOCALfloat32Hole position on plate (+X = +RA) in mm
YFOCALfloat32Hole position on plate (+Y = +DEC) in mm
SOURCETYPEstrString expressing type of source (similar to OBJTYPE in DR8 and earlier)
TARGETTYPEstrGeneral type of target ("SCIENCE", "STANDARD" or "SKY")
THING_ID_TARGETINGint64Resolve THING_ID in SDSS imaging for targeted object
THING_IDint32Resolve THING_ID in SDSS imaging for best positional match
PRIMTARGETint32Deprecated version of primary (science) target flags (meanings highly overloaded)
SECTARGETint32Deprecated version of secondary (calibration) target flags (meanings highly overloaded)
LEGACY_TARGET1int32Primary (science) target flags for SDSS-I and SDSS-II Legacy survey
LEGACY_TARGET2int32Secondary (calibration) target flags for SDSS-I and SDSS-II Legacy survey
SPECIAL_TARGET1int64Primary (science) target flags for SDSS-I and SDSS-II special program targets
SPECIAL_TARGET2int64Secondary (calibration) target flags for SDSS-I and SDSS-II special program targets
SEGUE1_TARGET1int32Primary (science) target flags for SEGUE-1 targets
SEGUE2_TARGET1int32Primary (science) target flags for SEGUE-2 targets
SEGUE2_TARGET2int32Secondary (calibration) target flags for SEGUE-2 targets
MARVELS_TARGET1int32Primary (science) target flags for MARVELS targets
MARVELS_TARGET2int32Secondary (calibration) target flags for MARVELS targets
BOSS_TARGET1int64Primary (science) target flags for BOSS targets
BOSS_TARGET2int64 Always set to zero (placeholder for BOSS target flags never used)
EBOSS_TARGET0int64SEQUELS, TDSS and SPIDERS target selection flags
EBOSS_TARGET1int64eBOSS, TDSS and SPIDERS target selection flags for main eBOSS survey
EBOSS_TARGET2int64eBOSS, TDSS and SPIDERS target selection flags for main eBOSS survey
ANCILLARY_TARGET1int64Target flags for BOSS ancillary targets
ANCILLARY_TARGET2int64More target flags for BOSS ancillary targets
SPECTROGRAPHIDint16Which spectrograph (1 or 2)
PLATEint32Plate number (each plate corresponds to an actual plug plate)
TILEint32Tile number (each tile can have several plates drilled for it)
MJDint32Modified Julian Day of observation
FIBERIDint32Fiber number
OBJIDint32[5]SDSS photometric object identification numbers (RUN, RERUN, CAMCOL, FIELD, ID)
PLUG_RAfloat64Right ascension of hole (J2000 deg)
PLUG_DECfloat64Declination of hole (J2000 deg)
CLASSstrBest spectroscopic classification ("STAR", "GALAXY" or "QSO")
SUBCLASSstrBest spectroscopic subclassification
Zfloat32Best redshift
Z_ERRfloat32Error in best redshift
RCHI2float32Reduced chi-squared of best fit
DOFint32Number of degrees of freedom in best fit
RCHI2DIFFfloat32Difference in reduced chi-squared between best and second best fit
TFILEstrFile that best fit template comes from in idlspec2d product
TCOLUMNint32[10]Columns of template files that correspond to each template
NPOLYint32Number of polynomial terms in fit
THETAfloat32[10]Template coefficients of best fit
VDISPfloat32Velocity dispersion (km/s)
VDISP_ERRfloat32Error in velocity dispersion (km/s)
VDISPZfloat32Redshift associated with best-fit velocity dispersion
VDISPZ_ERRfloat32Error in redshift associated with best-fit velocity dispersion
VDISPDOFint32Number of degrees of freedom in velocity dispersion fit
VDISPCHI2float32Chi-squared for best-fit velocity dispersion
VDISPNPIXfloat32Number of pixels overlapping the templates used in the velocity dispersion fit
WAVEMINfloat32Minimum observed (vacuum) wavelength (Angstroms)
WAVEMAXfloat32Maximum observed (vacuum) wavelength (Angstroms)
WCOVERAGEfloat32Coverage in wavelength, in units of log10 wavelength
ZWARNINGint32Bitmask of spectroscopic warning values; 0 means everything is OK
SN_MEDIAN_ALLfloat32Median signal-to-noise per pixel across full spectrum
SN_MEDIANfloat32[5]Median signal-to-noise per pixel within each of the ugriz bandpasses
CHI68Pfloat3268-th percentile value of abs(chi) of the best-fit synthetic spectrum to the actual spectrum (around 1.0 for a good fit)
FRACNSIGMAfloat32[10]Fraction of pixels deviant by more than N sigma relative to best-fit (for 1,2,..,10 sigma)
FRACNSIGHIfloat32[10]Fraction of pixels high by more than N sigma relative to best-fit (for 1,2,..,10 sigma)
FRACNSIGLOfloat32[10]Fraction of pixels low by more than N sigma relative to best-fit (for 1,2,..,10 sigma)
SPECTROFLUXfloat32[5]Spectrum projected onto ugriz filters (nanomaggies)
SPECTROFLUX_IVARfloat32[5]Inverse variance of spectrum projected onto ugriz filters (nanomaggies)
SPECTROSYNFLUXfloat32[5]Best-fit template spectrum projected onto ugriz filters (nanomaggies)
SPECTROSYNFLUX_IVARfloat32[5]Inverse variance of best-fit template spectrum projected onto ugriz filters (nanomaggies)
SPECTROSKYFLUXfloat32[5]Sky flux in each of the ugriz imaging filters (nanomaggies)
ANYANDMASKint32For each bit, records whether any pixel in the spectrum has that bit set in its ANDMASK
ANYORMASKint32For each bit, records whether any pixel in the spectrum has that bit set in its ORMASK
SPEC1_Gfloat32Signal-to-noise squared for spectrograph #1, at g=20.20 for SDSS spectrograph spectra, g=21.20 for BOSS spectrograph spectra
SPEC1_Rfloat32Signal-to-noise squared for spectrograph #1, at r=20.25 for SDSS spectrograph spectra, r=20.20 for BOSS spectrograph spectra
SPEC1_Ifloat32Signal-to-noise squared for spectrograph #1, at i=19.90 for SDSS spectrograph spectra, i=20.20 for BOSS spectrograph spectra
SPEC2_Gfloat32Signal-to-noise squared for spectrograph #2, at g=20.20 for SDSS spectrograph spectra, g=21.20 for BOSS spectrograph spectra
SPEC2_Rfloat32Signal-to-noise squared for spectrograph #2, at r=20.25 for SDSS spectrograph spectra, r=20.20 for BOSS spectrograph spectra
SPEC2_Ifloat32Signal-to-noise squared for spectrograph #2, at i=19.90 for SDSS spectrograph spectra, i=20.20 for BOSS spectrograph spectra
ELODIE_FILENAMEstrFile name for best-fit ELODIE star
ELODIE_OBJECTstrStar name for ELODIE star
ELODIE_SPTYPEstrELODIE star spectral type
ELODIE_BVfloat32(B-V) color index for ELODIE star (mag)
ELODIE_TEFFfloat32Effective temperature of ELODIE star (Kelvin)
ELODIE_LOGGfloat32log10(gravity) of ELODIE star
ELODIE_FEHfloat32Metallicity [Fe/H] of ELODIE star
ELODIE_Zfloat32Redshift fit to ELODIE star
ELODIE_Z_ERRfloat32Error in redshift fit to ELODIE star
ELODIE_Z_MODELERRfloat32Standard deviation in redshift among the 12 best-fit ELODIE stars
ELODIE_RCHI2float32Reduced chi-squared of fit to best ELODIE star
ELODIE_DOFint32Degrees of freedom in fit to best ELODIE star
Z_NOQSOfloat32Best redshift when ignoring QSO fits, recommended for BOSS CMASS and LOWZ targets; calculated only for survey='boss' spectra, not for any SDSS spectrograph data
Z_ERR_NOQSOfloat32Error in Z_NOQSO redshift
ZWARNING_NOQSOint32For Z_NOQSO redshift, the bitmask of spectroscopic warning values; 0 means everything is OK
CLASS_NOQSOstrSpectroscopic classification for Z_NOQSO redshift
SUBCLASS_NOQSOstrSpectroscopic subclassification for Z_NOQSO redshift
RCHI2DIFF_NOQSOfloat32Difference in reduced chi-squared between best and second best fit for Z_NOQSO redshift
Z_PERSONfloat32Visual-inspection redshift
CLASS_PERSONint32Visual-inspection classification (0=not inspected or unknown, 1=star, 2=narrow emission-line galaxy, 3=QSO, 4=galaxy)
Z_CONF_PERSONint32Visual-inspection confidence (0=not inspected or no confidence, 1,2=low confidence, 3,4=high confidence)
COMMENTS_PERSONstrVisual-inspection comments
CALIBFLUXfloat32[5]ugriz fluxes used for calibrations (nanomaggies)
CALIBFLUX_IVARfloat32[5]Inverse variances of ugriz fluxes used for calibrations (nanomaggies)