Combined Spectra

File Format: FITS image

Name: spPlate-YYYY-ZZZZZ.fits, where YYYY is the plate ID and ZZZZZ is the MJD the plate was observed. If the same mapping of this plate was observed on several nights, then this MJD corresponds to the last night it was observed.

Produced by: spectro2d

Used by: spectro1d

Archived? Yes. Tracked file.

Description

The combined spectrum over all exposures (potentially spanning multiple nights) for a given mapped plate.

In summary, this file contains the following:

HDU #0 = Flux in units of 10^(-17) erg/cm/s/Ang [FLOAT]
HDU #1 = Inverse variance (1/sigma^2) for the above [FLOAT]
HDU #2 = AND mask [32-bit INT]
HDU #3 = OR mask [32-fit INT]
HDU #4 = Wavelength dispersion in pixels [FLOAT]
HDU #5 = Plug-map structure from plPlugMapM file [BINARY FITS TABLE]

HDU #0 (Primary Header)

Contains the flux in units of 10^-17 erg/s/cm^2/Ang. The length of the spectra (NAXIS1) can vary, depending on the pixel binning and wavelength coverage. The number of spectra (NAXIS2) is always 640.

SIMPLE  =                    T / FIT STANDARD                                   
BITPIX  =                  -32 / FITS BITS/PIXEL                                
NAXIS   =                    2 / NUMBER OF AXES                                 
NAXIS1  =                 3849 / WIDTH (TOTAL!)                                 
NAXIS2  =                  640 / HEIGHT (TOTAL!)                                
EXTEND  =                    T /                                                
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                 
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)             
AUTHOR  = 'Scott Burles & David Schlegel' /                                     
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 /                                                
NWORDER =                    2 / Linear-log10 coefficients                      
WFITTYPE= 'LOG-LINEAR'         / Linear-log10 dispersion                        
COEFF0  =        3.57920000000 / Central wavelength (log10) of first pixel      
COEFF1  =    0.000100000000000 / Log10 dispersion per pixel                     
UNAME   = 'fnpc73  '           /                                                
SMEARUSE=                    T / Smear image used?                              
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' /                     
CRVAL1  =        3.57920000000 / Central wavelength (log10) of first pixel      
CD1_1   =    0.000100000000000 / Log10 dispersion per pixel                     
CRPIX1  =                    1 / Starting pixel (1-indexed)                     
CTYPE1  = 'LINEAR  '           /                                                
DC-FLAG =                    1 / Log-linear flag                                
BUNIT   = '10E-17 erg/cm/s/Ang' /                                               
END                                                                             

HDU #1

Contains the inverse variance in units of 1/(10^-17 erg/s/cm^2/Ang)^2. The dimensions are the same as the primary HDU.
XTENSION= 'IMAGE   '           / IMAGE extension                                
BITPIX  =                  -32 /                                                
NAXIS   =                    2 /                                                
NAXIS1  =                 3848 /                                                
NAXIS2  =                  640 /                                                
PCOUNT  =                    0 / No Group Parameters                            
GCOUNT  =                    1 / One Data Group                                 
WAT0_001= 'system=linear'      /                                                
WAT1_001= 'wtype=linear label=Wavelength units=Angstroms' /                     
CRVAL1  =        3.57980000000 / Central wavelength (log10) of first pixel      
CD1_1   =    0.000100000000000 / Log10 dispersion per pixel                     
CRPIX1  =                    1 / Starting pixel (1-indexed)                     
CTYPE1  = 'LINEAR  '           /                                                
DC-FLAG =                    1 / Log-linear flag                                
END                                                                             

HDU #2

Contains the AND bit mask. The dimensions are the same as the primary HDU.
XTENSION= 'IMAGE   '           / IMAGE extension                                
BITPIX  =                   32 /                                                
NAXIS   =                    2 /                                                
NAXIS1  =                 3848 /                                                
NAXIS2  =                  640 /                                                
PCOUNT  =                    0 / No Group Parameters                            
GCOUNT  =                    1 / One Data Group                                 
WAT0_001= 'system=linear'      /                                                
WAT1_001= 'wtype=linear label=Wavelength units=Angstroms' /                     
CRVAL1  =        3.57980000000 / Central wavelength (log10) of first pixel      
CD1_1   =    0.000100000000000 / Log10 dispersion per pixel                     
CRPIX1  =                    1 / Starting pixel (1-indexed)                     
CTYPE1  = 'LINEAR  '           /                                                
DC-FLAG =                    1 / Log-linear flag                                
END                                                                             

There are two masks, an "AND" mask and an "OR" mask. The spectra are constructed from 3 or more 15-minute observations, and the "AND" mask bits are set if that bit is set for each and every input observation. The "OR" mask bits are set if that bit is set for any of the observations.

The mask bits are set as follows:

  0 NOPLUG           Fiber not listed in plugmap file
  1 BADTRACE         Bad trace from routine TRACE320CRUDE
  2 BADFLAT          Low counts in fiberflat
  3 BADARC           Bad arc solution
  4 MANYBADCOLUMNS   >10% pixels are bad columns
  5 MANYREJECTED     >10% pixels are rejected in extraction
  6 LARGESHIFT       Large spatial shift between flat and object pos'n
  7 BADSKYFIBER      Sky Fiber shows extreme residuals
  8 NEARWHOPPER      Within 2 fibers of a whopping fiber (inclusive)
 10 SMEARIMAGE       Smear available for red and blue cameras
 11 SMEARHIGHSN      S/N sufficient for full smear fit
 12 SMEARMEDSN       S/N only sufficient for scaled median fit
 16 NEARBADPIXEL     Bad pixel within 3 pixels of trace
 17 LOWFLAT          Flat field less than 0.5
 18 FULLREJECT       Pixel fully rejected in extraction (INVVAR=0)
 19 PARTIALREJECT    Some pixels rejected in extraction
 20 SCATTEREDLIGHT   Scattered light significant
 21 CROSSTALK        Cross-talk significant
 22 NOSKY            Sky level unknown at this wavelength (INVVAR=0)
 23 BRIGHTSKY        Sky level > flux + 10*(flux_err)
                       AND sky > 1.25 * median(sky,99 pixels)
 24 NODATA           No data available in combine B-spline (INVVAR=0)
 25 COMBINEREJ       Rejected in combine B-spline
 26 BADFLUXFACTOR    Low flux-calibration or flux-correction factor
 27 BADSKYCHI        Chi^2 > 4 in sky residuals at this wavelength
 28 REDMONSTER       Contiguous region of bad chi^2 in sky residuals

HDU #3

Contains the OR bit mask. The dimensions are the same as the primary HDU.
XTENSION= 'IMAGE   '           / IMAGE extension                                
BITPIX  =                   32 /                                                
NAXIS   =                    2 /                                                
NAXIS1  =                 3848 /                                                
NAXIS2  =                  640 /                                                
PCOUNT  =                    0 / No Group Parameters                            
GCOUNT  =                    1 / One Data Group                                 
WAT0_001= 'system=linear'      /                                                
WAT1_001= 'wtype=linear label=Wavelength units=Angstroms' /                     
CRVAL1  =        3.57980000000 / Central wavelength (log10) of first pixel      
CD1_1   =    0.000100000000000 / Log10 dispersion per pixel                     
CRPIX1  =                    1 / Starting pixel (1-indexed)                     
CTYPE1  = 'LINEAR  '           /                                                
DC-FLAG =                    1 / Log-linear flag                                
END                                                                             

HDU #4

Contains the wavelength dispersion in units of pixels. The dimensions are the same as the primary HDU.
XTENSION= 'IMAGE   '           / IMAGE extension                                
BITPIX  =                  -32 /                                                
NAXIS   =                    2 /                                                
NAXIS1  =                 3848 /                                                
NAXIS2  =                  640 /                                                
PCOUNT  =                    0 / No Group Parameters                            
GCOUNT  =                    1 / One Data Group                                 
WAT0_001= 'system=linear'      /                                                
WAT1_001= 'wtype=linear label=Wavelength units=Angstroms' /                     
CRVAL1  =        3.57980000000 / Central wavelength (log10) of first pixel      
CD1_1   =    0.000100000000000 / Log10 dispersion per pixel                     
CRPIX1  =                    1 / Starting pixel (1-indexed)                     
CTYPE1  = 'LINEAR  '           /                                                
DC-FLAG =                    1 / Log-linear flag                                
END                                                                             

HDU #5

Contains the entries from the plPlugMapM file used for the Spectro-2D reduction. There are always 640 rows (one per object).
XTENSION= 'BINTABLE'           /Binary table written by MWRFITS                 
BITPIX  =                    8 /Required value                                  
NAXIS   =                    2 /Required value                                  
NAXIS1  =                  129 /Number of bytes per row                         
NAXIS2  =                  640 /Number of rows                                  
PCOUNT  =                    0 /Normally 0 (no varying arrays)                  
GCOUNT  =                    1 /Required value                                  
TFIELDS =                   16 /Number of columns in table                      
COMMENT                                                                         
COMMENT  *** Column formats ***                                                 
COMMENT                                                                         
TFORM1  = '5J      '           /                                                
TFORM2  = '6A      '           /                                                
TFORM3  = 'D       '           /                                                
TFORM4  = 'D       '           /                                                
TFORM5  = '5E      '           /                                                
TFORM6  = 'E       '           /                                                
TFORM7  = 'E       '           /                                                
TFORM8  = 'E       '           /                                                
TFORM9  = '19A     '           /                                                
TFORM10 = 'D       '           /                                                
TFORM11 = 'D       '           /                                                
TFORM12 = 'J       '           /                                                
TFORM13 = 'J       '           /                                                
TFORM14 = 'J       '           /                                                
TFORM15 = 'J       '           /                                                
TFORM16 = 'J       '           /                                                
COMMENT                                                                         
COMMENT  *** Column Names ***                                                   
COMMENT                                                                         
TTYPE1  = 'OBJID   '           /                                                
TTYPE2  = 'HOLETYPE '          /                                                
TTYPE3  = 'RA      '           /                                                
TTYPE4  = 'DEC     '           /                                                
TTYPE5  = 'MAG     '           /                                                
TTYPE6  = 'STARL   '           /                                                
TTYPE7  = 'EXPL    '           /                                                
TTYPE8  = 'DEVAUCL '           /                                                
TTYPE9  = 'OBJTYPE '           /                                                
TTYPE10 = 'XFOCAL  '           /                                                
TTYPE11 = 'YFOCAL  '           /                                                
TTYPE12 = 'SPECTROGRAPHID '    /                                                
TTYPE13 = 'FIBERID '           /                                                
TTYPE14 = 'THROUGHPUT '        /                                                
TTYPE15 = 'PRIMTARGET '        /                                                
TTYPE16 = 'SECTARGET '         /                                                
COMMENT                                                                         
COMMENT  *** End of required fields ***                                         
COMMENT                                                                         
END