1D Spectro Image

File Format: FITS image

Name: spSpec-mmmmm-pppp-fff.fit, where mmmmm is the mjd, pppp is the plate id number and fff is the fiber id number.

Produced by: spectro1d

Used by: opdb, sdbx

Archived? Yes.

Description

Line measurements and redshift determinations, as well as the spectrum, for a single object, summing over all of its exposures through a given mapped plate. Each file contains the following HDUs:

Primary Header

The spectrum. The first row is the spectrum, the second row is the continuum subtracted spectrum, the third row is the noise in the spectrum (standard deviation, in the same units as the spectrum), the forth row is the mask array. The spectra are binned log-linear. Units are 10^(-17) erg/cm/s^2/Ang.


SIMPLE  =                    T                                                  
BITPIX  =                  -32                                                  
NAXIS   =                    2                                                  
NAXIS1  =                 3849                                                  
NAXIS2  =                    4                                                  
TAI     =        4474845874.54 / 1st row - Number of seconds since Nov 17 1858  
RA      =            261.30167 / 1st row - Right ascension of telescope boresigh
DEC     =            60.926492 / 1st row - Declination of telescope boresight (d
EQUINOX =              2000.00 /                                                
RADECSYS= 'FK5     '           /                                                
AZ      =        212.819513333 / 1st row - Azimuth  (encoder) of tele (0=N?) (de
ALT     =        48.0575580000 / 1st row - Altitude (encoder) of tele        (de
AIRMASS =              1.28831 /                                                
FOCUS   = -999999999999.999999 / 1st row - Focus piston (microns?)              
DATE-OBS= '2000-09-05'         / 1st row - TAI date                             
TAIHMS  = '04:27:02.14'        / 1st row - TAI time (HH:MM:SS.SS) (TAI-UT = appr
TIMESYS = 'tai     '           / TAI, not UTC                                   
TAI-BEG =        4474843863.00 / Exposure Start Time                            
TAI-END =        4474846879.00 / Exposure End Time                              
MJD     =                51792 / MJD of observation                             
MJDLIST = '51792   '           /                                                
VERSION = 'v3_17_5_4'          / version of IOP                                 
CAMVER  = 'SPEC2 v4_5'         / Camera code version                            
OBSERVER= 'sjnk    '                                                            
OBSCOMM = 'science '                                                            
TELESCOP= 'SDSS 2.5-M'         / Sloan Digital Sky Survey                       
NEXP    =                   12 / Number of exposures in this file               
EXPID00 = 'b1-51792-00006429-00006426-00006427' / ID string for exposure 0      
EXPID01 = 'b1-51792-00006430-00006426-00006427' / ID string for exposure 1      
EXPID02 = 'b1-51792-00006431-00006437-00006427' / ID string for exposure 2      
EXPID03 = 'b2-51792-00006429-00006426-00006427' / ID string for exposure 3      
EXPID04 = 'b2-51792-00006430-00006426-00006427' / ID string for exposure 4      
EXPID05 = 'b2-51792-00006431-00006437-00006427' / ID string for exposure 5      
EXPID06 = 'r1-51792-00006429-00006426-00006438' / ID string for exposure 6      
EXPID07 = 'r1-51792-00006430-00006426-00006438' / ID string for exposure 7      
EXPID08 = 'r1-51792-00006431-00006437-00006438' / ID string for exposure 8      
EXPID09 = 'r2-51792-00006429-00006426-00006438' / ID string for exposure 9      
EXPID10 = 'r2-51792-00006430-00006426-00006438' / ID string for exposure 10     
EXPID11 = 'r2-51792-00006431-00006437-00006438' / ID string for exposure 11     
EXPT_B1 =              2700.00 / b1 camera exposure time (seconds)              
EXPT_B2 =              2700.00 / b2 camera exposure time (seconds)              
EXPT_R1 =              2700.00 / r1 camera exposure time (seconds)              
EXPT_R2 =              2700.00 / r2 camera exposure time (seconds)              
EXPTIME =              2700.00 / Minimum of exposure times for all cameras      
SPCOADD = 'Fri Jun 28 15:25:10 2002' / SPCOADD finished                         
FLAVOR  = 'science '           / Flavor of this sequence (e.g., dome flat, etc.)
QUALITY = 'unknown '           / night/image quality                            
RADEG   = 2.61302400000000E+02 / Right Ascension. (degrees)                     
DECDEG  = 6.09272200000000E+01 / Declination. (degrees)                         
PLATEID =                  354 / Plate Id                                       
TILEID  =                  153 / Tile Id                                        
CARTID  =                    2 /Cartridge used in this plugging                 
REDDEN  = '0.1724 0.1269 0.0920 0.0698 0.0495' / Median reddening vector for pla
MAPID   =              5179001 / Map Id                                         
NAME    = '0354-51790-01'      / Name of target; PlateId-MJD-Mapper ReRun       
NGUIDE  =              27.0000 / Number of guider frames during exposure        
SEEING20=              1.40667 / 20% seeing during exposure (arcsec)            
SEEING50=              1.50333 / 50% seeing during exposure (arcsec)            
SEEING80=              1.65667 / 80% seeing during exposure (arcsec)            
RMSOFF20=       0.308173333333 / 20% RMS offset of guide fibers (arcsec)        
RMSOFF50=       0.430279000000 / 50% RMS offset of guide fibers (arcsec)        
RMSOFF80=       0.549163333333 / 80% RMS offset of guide fibers (arcsec)        
COLBIN  =                    1 / Binning factor perpendicular to the columns    
ROWBIN  =                    1 / Binning factor perpendicular to the rows       
PROGRAM = 'binning 1   1 '     / Identifying name for CCD program               
SECFOCUS= -3.0000000000000E+02 / Secondary Mirror Position as reported by TCC   
GUIDEIMG= '/data/spectro/guider/gimg0084.fits' / Last archived guider image     
WTIME   =        968128309.000 / weatherData(timeStamp)                         
AIRTEMP =        16.8000000000 / weatherData(airtemp)                           
DEWPOINT=      -0.433333333333 / weatherData(dewpoint)                          
DEWDEP  =        17.2333333333 / weatherData(dewpointDep)                       
DUSTA   =        85468.0000000 / weatherData(dusta)                             
DUSTB   =        957.333333333 / weatherData(dustb)                             
DUSTC   =        99940.0000000 / weatherData(dustc)                             
DUSTD   =        955.333333333 / weatherData(dustd)                             
GUSTD   = 1.32300000000000E+02 / weatherData(gustd)                             
GUSTS   =        21.7000000000 / weatherData(gusts)                             
HUMIDITY=        30.9333333333 / weatherData(humidity)                          
HUMIDOUT=        30.6666666667 / weatherData(humidout)                          
PRESSURE=        21.7000000000 / weatherData(pressure)                          
WINDD   =        132.000000000 / weatherData(windd)                             
WINDS   =        17.5333333333 / weatherData(winds)                             
TEMP01  =       -93.6200000000 / CCD 01 Temperature                             
TEMP02  =       -93.3600000000 / CCD 02 Temperature                             
TEMP03  =       -92.5800000000 / CCD 03 Temperature                             
TEMP04  =       -92.8400000000 / CCD 04 Temperature                             
AZ_OFF  = 0.00000000000000E+00 / Azimuth Offset (Diamond Pointing)              
ALT_OFF = 0.00000000000000E+00 / Altitude Offset (Diamond Pointing)             
VERSIDL = '5.4     '           / Version of IDL                                 
VERSUTIL= 'v4_9_7  '           / Version of idlutils                            
VERSREAD= 'v4_9_8  '           / Version of idlspec2d for pre-processing raw dat
VERS2D  = 'v4_9_8  '           / Version of idlspec2d for 2D reduction          
VERSCOMB= 'v4_9_8  '           / Version of idlspec2d for combining multiple spe
VERSLOG = 'Unknown '           / Version of SPECLOG product                     
VERSFLAT= 'v1_4    '           / Version of SPECFLAT product                    
OPBC    = 'opBC-50000.par'     /                                                
OPCONFIG= 'opConfig-50000.par' /                                                
OPECALIB= 'opECalib-51577.par' /                                                
XSIGMA  =       0.947553247927 /                                                 
XSIGMIN =       0.842633000000 /                                                
XSIGMAX =        1.11480998993 /                                                
WSIGMA  =       0.937792500000 /                                                
WSIGMIN =       0.898409000000 /                                                
WSIGMAX =       0.988289000000 /                                                
PLUGFILE= 'plPlugMapM-0354-51790-01.par' /                                      
LAMPLIST= 'lamphgcdne.dat'     /                                                
SKYLIST = 'skylines.dat'       /                                                
HELIO_RV=        3.38344063555 / Heliocentric correction (added to velocities)  
VACUUM  =                    T / Wavelengths are in vacuum                      
SFLATTEN=                    T / Superflat has been applied                     
PSFSKY  =                    3 / Order of PSF skysubtraction                    
SKYCHI2 =       0.967572500439 / Mean chi^2 of sky-subtraction                  
SCHI2MIN=       0.931639000000 /                                                
SCHI2MAX=        1.01598000526 /                                                
PREJECT =             0.200000 / Profile area rejection threshold               
SPEC1_G =              19.9614 /(S/N)^2 for spec  1 at mag 20.20                
SPEC1_R =              30.2269 /(S/N)^2 for spec  1 at mag 20.25                
SPEC1_I =              25.6335 /(S/N)^2 for spec  1 at mag 19.90                
SPEC2_G =              18.0590 /(S/N)^2 for spec  2 at mag 20.20                
SPEC2_R =              28.4687 /(S/N)^2 for spec  2 at mag 20.25                
SPEC2_I =              23.9591 /(S/N)^2 for spec  2 at mag 19.90                
LOWREJ  =                    5 / Extraction: low rejection                      
HIGHREJ =                    8 / Extraction: high rejection                     
SCATPOLY=                    5 / Extraction: Order of scattered light polynomial
PROFTYPE=                    3 / Extraction profile: 1=Gaussian                 
NFITPOLY=                    1 / Extraction: Number of parameters in each profil
XCHI2   =              1.38691 / Extraction: Mean chi^2                         
XCHI2MIN=              1.20964 /                                                
XCHI2MAX=              1.66991 /                                                
ROFFSET1=          -0.00763309 /Mean r-band mag difference (spectro - photo)    
RSIGMA1 =             0.190664 /Stddev of r-band mag difference (spectro - photo
GROFF1  =            0.0870182 /Mean (g-r) color difference (spectro - photo)   
GRSIGMA1=             0.453493 /Stddev of (g-r) color difference (spectro - phot
ROFFSET2=           -0.0414150 /Mean r-band mag difference (spectro - photo)    
RSIGMA2 =             0.163316 /Stddev of r-band mag difference (spectro - photo
GROFF2  =            0.0145647 /Mean (g-r) color difference (spectro - photo)   
GRSIGMA2=             0.336159 /Stddev of (g-r) color difference (spectro - phot
NWORDER =                    2 / Linear-log10 coefficients                      
WFITTYPE= 'LOG-LINEAR'         / Linear-log10 dispersion                        
UNAME   = 'fnpc73  '           /                                                
SMEARUSE=                    T / Smear image used?                              
SFD_USED=                    T / SFD dust maps used?                            
XYGRSIG1=            0.0621177 / Sigma of (g-r) offsets as a fcn of plate x/y   
XYGRSIG2=            0.0191772 / Sigma of (g-r) offsets as a fcn of plate x/y   
MPGRSIG1=            0.0445317 / Sigma of (g-r)_model - (g-r)_photo Spec 1      
MPGRSIG2=            0.0306900 / Sigma of (g-r)_model - (g-r)_photo Spec 2      
MPGROFF1=            0.0247127 / Mean of (g-r)_model - (g-r)_photo of Spec 1    
MPGROFF2=           0.00158501 / Mean of (g-r)_model - (g-r)_photo of Spec 2    
FBADPIX =            0.0189197 / Fraction of bad pixels                         
FBADPIX1=            0.0178169 / Fraction of bad pixels on spectro-1            
FBADPIX2=            0.0200191 / Fraction of bad pixels on spectro-2            
WAT0_001= 'system=linear'      /                                                
WAT1_001= 'wtype=linear label=Wavelength units=Angstroms' /                     
CRPIX1  =                    1 / Starting pixel (1-indexed)                     
CTYPE1  = 'LINEAR  '           /                                                
DC-FLAG =                    1 / Log-linear flag                                
PIXMIN  = 0.00000000000000E+00 / Place Holder                                   
PIXMAX  = 2.04700000000000E+03 / Place Holder                                   
ARRAY1  = 'SPECTRUM'           / units of (10^-17 erg/s/cm^2/A                  
ARRAY2  = 'CONTINUUM-SUBTRACTED SPECTRUM' / units of (10^-17 erg/s/cm^2/A       
ARRAY3  = 'ERROR   '           / units of (10^-17 erg/s/cm^2/A                  
ARRAY4  = 'MASK    '           / mask bit array                                 
SN_G    = 8.04687000000000E+00 / Median S/N ration ig g'                        
MAG_G   = 1.95412000000000E+01 / Synthetic magnitude in g'                      
SN_R    = 1.08943000000000E+01 / Median S/N ratio in r'                         
MAG_R   = 1.92726000000000E+01 / Synthetic magnitude in r'                     
SN_I    = 8.89338000000000E+00 / Median S/N ratio in i'                         
MAG_I   = 1.91939000000000E+01 / Synthetic magnitude in i'                      
SCI_SN  = 5.64089000000000E+00 / Science signal to noise ratio                  
SMEAR_SN= 1.21036000000000E+00 / Smear signal to noise ratio                    
SM_LEG_0= 3.19574000000000E+00 / 1st legendre coeff. for smear correct          
SM_LEG_1= -2.1375500000000E+00 / 2nd legendre coeff. for smear correct          
SM_LEG_2= 1.38465000000000E+00 / 3rd legendre coeff. for smear correct          
OBJID   = ' 1359 0 4 56 265'   / run rerun camcol field objID                   
MAG     = ' 19.9526 19.4762 19.3762 19.1735 19.2537' / fiber Mags               
OBJTYPE = 'QSO     '           / object Type                                    
RAOBJ   = 2.61528710000000E+02 / RA(deg) of object                              
DECOBJ  = 6.07020680000000E+01 / DEC(deg) of object                             
XFOCAL  = 2.40806440000000E+01 / Primary Target Flag                            
YFOCAL  = -4.8912450000000E+01 / Secondary Target Flag                          
PRIMTARG=              1048580 / fiber ID                                       
SECTARGE=                    0 / fiber ID                                       
FIBERID =                  153 / fiber ID                                       
SPECID  =                    1 / spectrograph ID                                
NGOOD   =                 3838 / Number of Good Pixels                          
VERS_1D = 'v5_7_2  '           / Version of Spectro1d                           
BESTTEMP=                   20 / Best cross-correlation template                
BUNIT   = '1.0E-17 erg/cm^2/s/Ang' / Oct 2002 Version                           
COEFF0  = 3.57920000000000E+00 / Center wavelength (log10) of first pi          
COEFF1  = 1.00000000000000E-04 / Log10 dispersion per pixel                     
CRVAL1  = 3.57920000000000E+00 / Iraf zero point                                
CD1_1   = 1.00000000000000E-04 / Iraf dispersion                                
1D_PDATE= '10/20/02:05:04:36'  / 1D Processing/last Modification date           
SPEC_CLN=                    1 / Spectral Classn                      (allowed values are given below)
VEL_DIS = -9.9990000000000E+03 / Velocity dispersion (km/s)                     
VEL_DISE= -9.9990000000000E+03 / Error on Velocity Dispersion (km/s)            
Z       = -3.7987600000000E-05 / Final redshift                                 
Z_ERR   = 3.97400000000000E-04 / Redshift error                                 
Z_CONF  = 5.68167000000000E-01 / Redshift confidence                            
Z_STATUS=                    5 / Redshift Status                      (for legal values see below)     
Z_WARNIN=                 4128 / Redshift Warning Flags               (for legal values see below)
ECLASS  = -3.0499700000000E-01 / galaxy classification parameter                
ECOEFF1 = 9.58722000000000E-01 / 1st expansion coefficient                      
ECOEFF2 = -2.0545700000000E-01 / 2nd expansion coefficient                      
ECOEFF3 = 1.80952000000000E-01 / 3rd expansion coefficient                      
ECOEFF4 = -2.4917800000000E-02 / 4th expansion coefficient                      
ECOEFF5 = -7.2626400000000E-02 / 5th expansion coefficient                      
EXTEND  =                    T / Binary tables follow                           
END                                                                             

Flags used in mask array

Each pixel in the MASK array (row 4) is a bit mask, with the following legal values:
 SP_MASK_OK           =  0x000,      
 SP_MASK_NOPLUG       =  0x001,      /*  Fiber not listed in plugmap file                     */
 SP_MASK_BADTRACE     =  0x002,      /*  Bad trace from routine TRACE320CRUDE                 */
 SP_MASK_BADFLAT      =  0x004,      /*  Low counts in fiberflat                              */
 SP_MASK_BADARC       =  0x008,      /*  Bad arc solution                                     */
 SP_MASK_MANYBADCOL   =  0x010,      /*  More than 10% pixels are bad columns                 */
 SP_MASK_MANYREJECT   =  0x020,      /*  More than 10% pixels are rejected in extraction      */
 SP_MASK_LARGESHIFT   =  0x040,      /*  Large spatial shift between flat and object position */
 SP_MASK_NEARBADPIX   =  0x10000,    /*  Bad pixel within 3 pixels of trace                   */
 SP_MASK_LOWFLAT      =  0x20000,    /*  Flat field less than 0.5                             */
 SP_MASK_FULLREJECT   =  0x40000,    /*  Pixel fully rejected in extraction                   */
 SP_MASK_PARTIALREJ   =  0x80000,    /*  Some pixels rejected in extraction                   */
 SP_MASK_SCATLIGHT    =  0x100000,   /*  Scattered light significant                          */
 SP_MASK_CROSSTALK    =  0x200000,   /*  Cross-talk significant                               */
 SP_MASK_NOSKY        =  0x400000,   /*  Sky level unknown at this wavelength                 */
 SP_MASK_BRIGHTSKY    =  0x800000,   /*  Sky level > flux + 10*(flux error)                   */
 SP_MASK_NODATA       =  0x1000000,  /*  No data available in combine B-spline                */
 SP_MASK_COMBINEREJ   =  0x2000000,  /*  Rejected in combine B-spline                         */
 SP_MASK_BADFLUXFACTOR=  0x4000000,  /*  Low flux-calibration or flux-correction factor       */
 SP_MASK_BADSKYCHI    =  0x8000000,  /*  Chi^2 > 4 in sky residuals at this wavelength        */
 SP_MASK_REDMONSTER   =  0x10000000, /*  Contiguous region of bad chi^2 in sky residuals      */
 SP_MASK_EMLINE       =  0x40000000  /*  Emission line detected here                         */

Spectra classification:

The keyword SPEC_CLN stores the enumarated type. The following values are used:
 SPEC_UNKNOWN = 0
 SPEC_STAR    = 1
 SPEC_GALAXY  = 2
 SPEC_QSO     = 3
 SPEC_HIZ_QSO = 4 /* high redshift QSO, z>2.3, Ly-alpha finding code is triggered */ 
 SPEC_SKY     = 5 
 STAR_LATE    = 6 /* star dominated by molecular bands, Type M or later           */
 GAL_EM       = 7 /* emission line galaxy -- not set by the code                  */

Redshift status:

The keyword Z_STATUS stores a value indicating the status of the redshift determination:
 NOT_MEASURED   =  0   /* Not yet measured                                            */
 FAILED         =  1   /* Redshift measurement failed                                 */
 INCONSISTENT   =  2   /* Xcorr & emz redshifts both high-confidence but inconsistent */
 XCORR_EMLINE   =  3   /* Xcorr plus consistent emz redshift measurement              */
 XCORR_HIC      =  4   /* z determined from x-corr with high confidence               */
 XCORR_LOC      =  5   /* z determined from x-corr with low confidence                */
 EMLINE_XCORR   =  6   /* Emz plus consistent xcorr redshift measurement              */
 EMLINE_HIC     =  7   /* z determined from em-lines with high confidence             */
 EMLINE_LOC     =  8   /* z determined from em-lines with low confidence              */
 MANUAL_HIC     =  9   /* z determined "by hand" with high confidence                 */
 MANUAL_LOC     = 10   /* z determined "by hand" with low confidence                  */
 XCORR_4000BREAK= 11   /* Xcorr redshift determined when EW(4000break) > 0.95         */ 
 ABLINE_CAII    = 12   /* Redshift determined from average of CaII triplet fits       */
 

Redshift warning flags:

The keword Z_WARNIN is a mask bit, with the following legal values:
 Z_WARNING_OK       =  0x000,    /* no warnings                                      */
 Z_WARNING_NO_SPEC  =  0x001,    /* no spec                                          */
 Z_WARNING_NO_BLUE  =  0x002,    /* no blueside                                      */
 Z_WARNING_NO_RED   =  0x004,    /* no redside                                       */
 Z_WARNING_NOT_GAL  =  0x010,    /* classification does not match galaxy target      */
 Z_WARNING_NOT_QSO  =  0x020,    /* classification does not match qso target         */
 Z_WARNING_NOT_STAR =  0x040,    /* classification does not match star target        */
 Z_WARNING_GAL_COEF =  0x080,    /* strange galaxy coefficients                      */
 Z_WARNING_EMAB_INC =  0x100,    /* emission and absorbtion redshifts inconsistent  */
 Z_WARNING_AB_INC   =  0x200,    /* absorbtion redshifts inconsistent ,multiple peaks*/
 Z_WARNING_EM_INC   =  0x400,    /* emission redshifts inconsistent                 */
 Z_WARNING_HIZ      =  0x800,    /* redshift is   high                               */
 Z_WARNING_LOC      =  0x1000,   /* confidence is low                                */
 Z_WARNING_LOW_SNG  =  0x2000,   /* signal to noise is low in g'                     */
 Z_WARNING_LOW_SNR  =  0x4000,   /* signal to noise is low in r'                     */
 Z_WARNING_LOW_SNI  =  0x8000,   /* signal to noise is low in i'                     */
 Z_WARNING_4000break = 0x10000,  /* EW(4000break) > 0.95                             */
 Z_WARNING_CL_MAN   = 0x20000,   /* classification set manually */
 Z_WARNING_Z_MAN    = 0x40000    /* redshift set manually */

Line HDUs (HDU 1 and 2)

These HDUs list the measured properties of individual emission/absorption lines in the spectrum. There are two HDUs of this type. The first HDU of this type (HDU 1) lists all lines found automatically by the wavelet filter, with no apriori knowledge of the redshift. The second HDU of this type (HDU 2) lists all lines measured based on their expected positions from the highest-confidence emission line redshift. Under most circumstances, the line measurements in HDU 2 should be used.

The following lines are measured, those with positive weights are used to estimate the emission line redshifts for galaxies or qso's:


restWave meanOffset {galWeight qsoWeight} Name
1033.82 0.0 { 0.0 1.0} OVI
1215.67 0.0 { 0.0 9.0} Ly\\d\\ga
1240.81 -1.41 { 0.0 3.0} NV
1305.53 0.0 { 0.0 0.0} OI
1335.31 0.0 { 0.0 0.0} CII
1399.8 0.0 { 0.0 1.0} SiIV+OIV
1549.48 -3.62 { 0.0 8.0} CIV
1640.4 0.0 { 0.0 0.0} HeII
1665.85 0.0 { 0.0 0.0} OIII
1857.4 0.0 { 0.0 0.0} AlIII
1908.734 0.0 { 0.0 7.0} CIII
2326.0 0.0 { 0.0 0.5} CII
2439.5 0.0 { 0.0 0.0} NeIV
2799.117 1.203 { 1.0 8.0} MgII
3346.79 0.0 { 0.0 0.0} NeV
3426.85 0.0 { 0.0 0.0} NeV
3727.092 1.208 { 5.0 1.0} OII
3729.875 0.0 { 0.0 0.0} OII
3798.976 0.0 { -1.0 0.0} H\\d\\gh
3836.47 0.0 { -1.0 0.0} H\\d\\gy
3889.0 0.0 { -1.0 0.0} HeI
3934.777 0.0 {-1.0 0.0} K
3969.588 0.0 {-1.0 0.0} H
4072.3 0.0 { 0.0 0.0} SII
4102.89 0.0 { 0.5 2.0} H\\d\\gd
4305.61 0.0 {-1.0 0.0} G
4341.68 0.0 { 1.0 3.0} H\\d\\gg
4364.436 0.0 { 0.0 0.0} OIII
4862.68 0.0 { 2.0 4.0} H\\d\\gb
4960.295 0.0 { 2.0 2.0} OIII
5008.240 0.0 { 3.0 2.0} OIII
5176.7 0.0 {-1.0 0.0} Mg
5895.6 0.0 {-1.0 0.0} Na
6302.046 0.0 { 0.0 0.0} OI
6365.536 0.0 { 0.0 0.0} OI
6549.86 0.0 { 3.0 0.0} NII
6564.61 0.0 { 8.0 8.0} H\\d\\ga
6585.27 0.0 { 3.0 0.0} NII
6707.89 0.0 { 0.0 0.0} Li
6718.29 0.0 { 3.0 0.0} SII
6732.67 0.0 { 3.0 0.0} SII
8500.36 0.0 { 0.0 0.0} CaII
8544.44 0.0 { 0.0 0.0} CaII
8664.52 0.0 { 0.0 0.0} CaII

XTENSION= 'BINTABLE'                                                            
BITPIX  =                    8                                                  
NAXIS   =                    2                                                  
NAXIS1  =                   89                                                  
NAXIS2  =                   10                                                  
PCOUNT  =                    0                                                  
GCOUNT  =                    1                                                  
TFIELDS =                   23                                                  
TFORM1  = '1E      '                                                            
TTYPE1  = 'wave    '                       / Line center                                                            
TUNIT1  = 'Å '
TFORM2  = '1E      '                                                            
TTYPE2  = 'waveErr '                       / Error in line center                     
TUNIT2  = 'Å '
TFORM3  = '1E      '                                                            
TTYPE3  = 'waveMin '                       / Minimum wavelength of line influence              
TUNIT3  = 'Å '
TFORM4  = '1E      '                                                            
TTYPE4  = 'waveMax '                       / Maximum wavelength of line influence                                 
TUNIT4  = 'Å '
TFORM5  = '1E      '                                                            
TTYPE5  = 'sigma   '                       / Sigma of fitted Gaussian                        
TUNIT5  = 'Å '
TFORM6  = '1E      '                                                            
TTYPE6  = 'sigmaErr'                       / Error in sigma                                                            
TUNIT6  = 'Å '
TFORM7  = '1E      '                                                            
TTYPE7  = 'sigmaMin'                       / Minimum sigma allowed for fit                        
TUNIT7  = 'Å '
TFORM8  = '1E      '                                                            
TTYPE8  = 'sigmaMax'                       / Maximum sigma allowed for fit                      
TUNIT8  = 'Å '
TFORM9  = '1E      '                                                            
TTYPE9  = 'height  '                       / Height of gaussian                                                            
TUNIT9  = '10^-17 ergs/s/cm^2/Å'
TFORM10 = '1E      '                                                            
TTYPE10 = 'heightErr'                      / Error in height                                                           
TUNIT10 = '10^-17 ergs/s/cm^2/Å'
TFORM11 = '1E      '                                                            
TTYPE11 = 'continuum'                      / Value of continuum at line center                      
TUNIT11 = '10^-17 ergs/s/cm^2/Å'
TFORM12 = '1E      '                                                            
TTYPE12 = 'ew      '                       / Equivalent width                                                           
TUNIT12 = 'Å '
TFORM13 = '1E      '                                                            
TTYPE13 = 'ewErr   '                       / Error in equivalent width                                
TUNIT13 = 'Å '
TFORM14 = '1E      '                                                            
TTYPE14 = 'ewMin   '                       / Minimum equilavelent width allowed for line detection      
TUNIT14 = 'Å '
TFORM15 = '1E      '                                                            
TTYPE15 = 'specIndex'                      / Spectral index                                                          
TUNIT15 = 'unitless'
TFORM16 = '1E      '                                                            
TTYPE16 = 'nsigma  '                       / Significance of line in number of sigma                                
TUNIT16 = 'unitless'
TFORM17 = '1E      '                                                            
TTYPE17 = 'chisq   '                       / Chi-squared of fit                                                            
TUNIT17 = 'unitless'
TFORM18 = '1J      '                                                            
TTYPE18 = 'nu      '                       / Degrees of freedom = npix - 3                           
TUNIT18 = 'unitless'
TFORM19 = '1E      '                                                            
TTYPE19 = 'restWave'                       / Restwavelength, also serves as line ID                        
TUNIT19 = 'Å '
TFORM20 = '1E      '                                                            
TTYPE20 = 'weight  '                       / Weight of line in fit                                                 
TUNIT20 = 'unitless'
TFORM21 = '1E      '                                                            
TTYPE21 = 'z       '                       / Redshift of this line                             
TUNIT21 = 'unitless'
TFORM22 = '1E      '                                                            
TTYPE22 = 'zErr    '                       / Error in redshift                                                            
TUNIT22 = 'unitless'
TFORM23 = '1A      '                                                            
TTYPE23 = 'lineMask'                       / Line mask                                                           
TUNIT23 = 'unitless'
COMMENT 'lineMask' is a bit mask, with the following bits defined
COMMENT    SP_LINE_WAVELET = 0x001, /* detected by wavelet filter */
COMMENT    SP_LINE_WZ      = 0x002, /* detected by Wei Zheng algorithm */
COMMENT    SP_LINE_BLENDED = 0x004, /* blended with another line */  
COMMENT    SP_LINE_MINIMIZE= 0x008  /* line & continuum fitted simultaneously*/

Emission Redshift HDU (HDU 3)

Redshift determinations based on sets of emission lines. There is one HDU of this type. There may be multiple entries, with each entry corresponding to a different set of lines.
XTENSION= 'BINTABLE'                                                           
BITPIX  =                    8                                                 
NAXIS   =                    2                                                 
NAXIS1  =                   24                                                 
NAXIS2  =                  XXX
PCOUNT  =                    0                                                 
GCOUNT  =                    1                                                 
TFIELDS =                    6                                                 
TFORM1  = '1E      '                                                           
TTYPE1  = 'z       '           / Redshift
TUNIT1  = 'unitless'
TFORM2  = '1E      '                                                           
TTYPE2  = 'zErr    '           / Error in redshift
TUNIT2  = 'unitless'
TFORM3  = '1E      '                                                           
TTYPE3  = 'conf    '           / Confidence in redshift
TUNIT3  = 'unitless'
TFORM4  = '1J      '                                                           
TTYPE4  = 'nFit'               / Number of matched lines
TUNIT4  = 'unitless'
TFORM5  = '1E      '                                                           
TTYPE5  = 'wtFit'              / Weight of fit lines
TUNIT5  = 'unitless'

Cross-Correlation Redshift HDU (HDU 4)

Redshift determinations from cross-correlations. There is one HDU of this type. More than one peak may be measured in each cross-correlation function (i.e., for each template).
XTENSION= 'BINTABLE'                                                            
BITPIX  =                    8                                                  
NAXIS   =                    2                                                  
NAXIS1  =                   48                                                  
NAXIS2  =                   31                                                  
PCOUNT  =                    0                                                  
GCOUNT  =                    1                                                  
TFIELDS =                   12                                                  
TFORM1  = '1J      '                                                            
TTYPE1  = 'temp_no '           / ID of template used                                                            
TUNIT1  = 'unitless'
TFORM2  = '1J      '                                                            
TTYPE2  = 'peak_no '           / 1=first peak, 2=second peak, etc for templat                                      
TUNIT2  = 'unitless'
TFORM3  = '1E      '                                                            
TTYPE3  = 'shift   '           / Number of pixels between between object and template              
TUNIT3  = 'pixels  '
TFORM4  = '1E      '                                                            
TTYPE4  = 'z       '           / Redshift from this correlation peak                                  
TUNIT4  = 'unitless'
TFORM5  = '1E      '                                                            
TTYPE5  = 'zErr    '           / Error in redshift                                                            
TUNIT5  = 'unitless'
TFORM6  = '1E      '                                                            
TTYPE6  = 'r       '           / Tonry & Davis R value                                  
TUNIT6  = 'unitless'
TFORM7  = '1E      '                                                            
TTYPE7  = 'con     '           / Confidence                                                            
TUNIT7  = 'unitless'
TFORM8  = '1E      '                                                            
TTYPE8  = 'height  '           / Height of CCF peak                                                            
TUNIT8  = 'unitless'
TFORM9  = '1E      '                                                            
TTYPE9  = 'width   '           / Width of CCF peak                                                            
TUNIT9  = 'unitless'
TFORM10 = '1E      '                                                            
TTYPE10 = 'widthErr'           / Error on the width of CCF peak                                 
TUNIT10 = 'unitless'
TFORM11 = '1E      '                                                            
TTYPE11 = 'delta   '           / Error on the location CCF peak                                           
TUNIT11  = 'unitless'
TFORM12 = '1E      '                                                            
TTYPE12 = 'rms     '           / Rms of CCF                                                           
TUNIT12 = 'unitless'

Line Index HDU (HDU 5)

A number of standard line indices and flux ratios are stored here. There is one HDU of this type.

The following indices are measured:

Line Indices

 

We calculate the Lick Indices Brodie & Hanes 1996 (note, however, that the Lick standards are too bright to be observed by SDSS and therefore these indices are not on the Lick system in the classical sense) and those of Diaz, Terlevich & Terlevich 1989.

This table defines the indices:
 
Name Index Begin Index End Red Cont Begin Red Cont End Blue Cont Begin Blue Cont End
Lick_CN1 4143.375 4178.375 4081.375 4118.875 4245.375 4285.375
Lick_CN2 4143.375 4178.375 4085.125 4097.625 4245.375 4285.375
Lick_Ca4227 4223.500 4236.000 4212.250 4221.000 4242.250 4252.250
Lick_G4300 4282.625 4317.625 4267.625 4283.875 4320.125 4333.375
Lick_Fe4383 4370.375 4421.625 4360.375 4371.625 4444.125 4456.625
Lick_Ca4455 4453.375 4475.875 4447.125 4455.875 4478.375 4493.375
Lick_Fe4531 4515.500 4560.500 4505.500 4515.500 4561.750 4580.500
Lick_C4668 4635.250 4721.500 4612.750 4631.500 4744.000 4757.750
Lick_Hb 4848.875 4877.625 4828.875 4848.875 4877.625 4892.625
Lick_Fe5015 4979.000 5055.250 4947.750 4979.000 5055.250 5066.500
Lick_Mg1 5070.375 5135.375 4896.375 4958.875 5302.375 5367.375
Lick_Mg2 5155.375 5197.875 4896.375 4958.875 5302.375 5367.375
Lick_Mgb 5143.875 5162.625 5161.375 5193.875 5192.625 5207.625
Lick_Fe527 5247.375 5287.375 5234.875 5249.875 5287.375 5319.875
Lick_Fe5335 5314.125 5354.125 5306.625 5317.875 5355.375 5365.375
Lick_Fe5406 5390.250 5417.750 5379.000 5390.250 5417.750 5427.750
Lick_Fe5709 5698.375 5722.125 5674.625 5698.375 5724.625 5738.375
Lick_Fe5782 5778.375 5798.375 5767.125 5777.125 5799.625 5813.375
Lick_NaD 5878.625 5911.125 5862.375 5877.375 5923.875 5949.875
Lick_TiO1 5938.875 5995.875 5818.375 5850.875 6040.375 6105.375
Lick_TiO2 6191.375 6273.875 6068.375 6143.375 6374.375 6416.875
B&H_CNB 3810.0 3910.0 3785.0 3810.0 3910.0 3925.0
B&H_H=K 3925.0 3995.0 3910.0 3925.0 3995.0 4010.0
B&H_CaI 4215.0 4245.0 4200.0 4215.0 4245.0 4260.0
B&H_G 4285.0 4315.0 4275.0 4285.0 4315.0 4325.0
B&H_CaI 4215.0 4245.0 4200.0 4215.0 4245.0 4260.0
B&H_G 4285.0 4315.0 4275.0 4285.0 4315.0 4325.0
B&H_Hb 4830.0 4890.0 4800.0 4830.0 4890.0 4920.0
B&H_MgG 5150.0 5195.0 5125.0 5150.0 5195.0 5220.0
B&H_MH 4940.0 5350.0 4740.0 4940.0 5350.0 5550.0
B&H_FC 5250.0 5280.0 5225.0 5250.0 5280.0 5305.0
B&H_NaD 5865.0 5920.0 5835.0 5865.0 5920.0 5950.0
DTT_CaII8498 8483.0 8513.0 8447.5 8462.5 8842.5 8857.5
DTT_CaII8542 8527.0 8557.0 8447.5 8462. 8842.5 8857.5
DTT_CaII8662 8467.0 8677.0 8447.5 8462.5 8842.5 8857.5
DTT_MgI8807 8799.5 8814.5 8775.0 8787.0 8845.0 8855.0

We also calculate the following line rations:
 
 
Name Red Begin Red End Blue Begin Blue End
4000Abreak 3750. 3950. 4050. 4250.
HKratio 3920. 3945. 3955. 3980.


XTENSION= 'BINTABLE'                                                            
BITPIX  =                    8                                                  
NAXIS   =                    2                                                  
NAXIS1  =                   51                                                  
NAXIS2  =                   32                                                  
PCOUNT  =                    0                                                  
GCOUNT  =                    1                                                  
TFIELDS =                    9                                                  
TFORM1  = '19A     '                                                            
TTYPE1  = 'name    '          / Name of the line index                                                  
TUNIT1  = 'unitless'
TFORM2  = '1E      '                                                            
TTYPE2  = 'ew      '          / Equivalent width of the line index (or flux ratio in the case of 4000Abreak, and HKratio)
TUNIT2  = 'Å '
TFORM3  = '1E      '                                                            
TTYPE3  = 'ewErr   '          / Error on the equivalent width
TUNIT3  = 'Å '
TFORM4  = '1E      '                                                            
TTYPE4  = 'mag     '          / Magnitude of the line index                                                  
TUNIT4  = 'unitless'
TFORM5  = '1E      '                                                            
TTYPE5  = 'magErr  '          / Error on the magnitude                                                  
TUNIT5  = 'unitless'
TFORM6  = '1E      '                                                            
TTYPE6  = 'waveMin '          / Minimum wavelength used to calculate the index
TUNIT6  = 'unitless'
TFORM7  = '1E      '                                                            
TTYPE7  = 'waveMax '          / Maximum wavelength used to calculate the index
TUNIT7  = 'unitless'
TFORM8  = '1E      '                                                            
TTYPE8  = 'z       '          / Redshift used to calculate the index
TUNIT8  = 'unitless'
TFORM9  = '1E      '                                                            
TTYPE9  = 'sn      '          / Signal to noise ratio over the index                                  
TUNIT9  = 'unitless'

Mask and Resolution HDU (HDU 6)

The masks as passed from spPlate*.fit (the mask bit values are a subset of those used in the mask array above), as well as the resolution. The length of this table should be the same as the length of the spectrum. There is one HDU of this type.

The resolution column is copied from HDU 4 of the spPlate*.fit file. It contains the RMS resolution at each pixel in units of pixels. To get the FWHM resolution, multiply the pixel values by sqrt(8*ln(2)) ∼ 2.35. Since the spectra are binned with constant logarithmic dispersion, the pixel size is fixed in velocity space at 69 km/s = ln(10) * c * 0.0001, where 0.0001 is the log10 dispersion per pixel (stored in the primary header keyword CD1_1). To convert to resolution in wavelength units, multiply by the local pixel size in wavelength units, which is ln(10) * lambda * 0.0001 where lambda is the wavelength of the pixel and 0.0001 is again the log10 dispersion.

XTENSION= 'BINTABLE'                                                            
BITPIX  =                    8                                                  
NAXIS   =                    2                                                  
NAXIS1  =                   12                                                  
NAXIS2  =                 3850                                                  
PCOUNT  =                    0                                                  
GCOUNT  =                    1                                                  
TFIELDS =                    3                                                  
TFORM1  = '1J      '                                                            
TTYPE1  = 'andMask '             / AND mask
TUNIT1  = 'unitless'
TFORM2  = '1J      '                                                            
TTYPE2  = 'orMask  '             / OR mask
TUNIT2  = 'unitless'
TFORM3  = '1E      '                                                            
TTYPE3  = 'dispRes '             / Wavelength dispersion
TUNIT3  = 'pixels  '