Telescope Data Center

Hectospec
Data Header Keyword Definitions
Alphabetic Order (Header Order)

Hectospec Image
[TDC Home]  [TDC Search] [OIR Home]
KeywordSample ValueCommentDescription
ADC 'SAO ADC ' ADC identifier
AIRMASS 1.026 airmass
ALTTIMIN 0 alttiming, milli-seconds
AMPNAME 'ampid 1-1' Name of first amplifier
ATM1_1 1.0000000 Amplifier transform matrix The amplifier coordinate system (As,Ap) is based on the order in which pixels are read. The the serial coordinate is As and the parallel coordinate is Ap. The coordinates begin with one for the first CCD pixel (actual charge well) that the controller records or uses in binning and increments by one for each "unbinned" pixel. If the controller always skips some initial columns or lines which are never used (such as for transient settling) then these are not counted. Prescan pixels which are recorded with the image data will have amplifier coordinates less than one. The general linear transformation between the amplifier and CCD coordinates is given by
As = ATM1_1 * Cx + ATM1_2 * Cy + ATV1
Ap = ATM2_1 * Cx + ATM2_2 * Cy + ATV2
Cx = ( ATM2_2 * (As - ATV1) - ATM1_2 * (Ap - ATV2)) / (ATM1_1 * ATM2_2 - ATM1_2 * ATM2_1)
Cy = (-ATM2_1 * (As - ATV1) + ATM1_1 * (Ap - ATV2)) / (ATM1_1 * ATM2_2 - ATM1_2 * ATM2_1)
See the NOAO website for more details.
ATM2_2 1.0000000 Amplifier transform matrix
ATV1 0.0000000 Amplifier transform vector
ATV2 0.0000000 Amplifier transform vector
BITPIX -32Bits per pixel-32 = 4-byte floating point
CAMGAIN 'UNDEFINED' camera gain state
CAT-ID '4_12_20_37_50 ' telescope catalog obj name
CAT-DEC '30:31:02.739 ' telescope catalog dec (degrees)
CAT-RA '9:20:11.359 ' telescope catalog ra (hours)
CCDGAIN 'UNDEFINED' CCD gain state
CCDSIGNM '/sbin/hecsc.bin' ccdsignal file
CCDLOSTB 0 CCD controller lost buffers
CCDOVERR 0 CCD controller buffer overruns
CCDSEC '[1:1024,1:4608]'First amplifier limits in pixels
CCDSUM '1 1 ' on chip summation
CCDTEMP -119.8200000CCD temperature in degrees Celsius
CCDTMOUT 1 CCD controller timeouts
CIFOCUS '0.8700 ' commanded focus position
COMMENT Data taken with the Hectospec multifiber spectrograph
COMMENT Built at SAO and operated at the MMT f/5 Focus
COMMENT STU Preform Polymicro Fibers are 250u or 1.5arcs at focal plane
CORRCTOR 'Wide-Field Correct' telescope corrector
CTILTPOS '-1.9260 ' commanded tiltpos
DARKTIME 1200. total elapsed time, seconds
DATE '2004-08-30T21:06:17'Time file was created
DATE-OBS '2004-04-13T04:16:47' UT date/time of start of exposure
DEC '30:42:19.764' declination (dd:mm:ss)
DETECTOR 'specs ' detector name
DETSEC '[1:1024,97:4704]' Detector data sectionMapping of the CCD section to detector coordinates
DETSIZE '[1:4098,1:4800]'Limiting dimensions of detectors in pixels
DEWTEMP -900.0000000
DISPERSE '270_gpm ' disperser
DWELL 15 sample integration time, microseconds
DTM1_1 1.0000000Detector transform matrix The final coordinate system is the detector coordinate system (Dx,Dy). This is important when multiple amplifiers and/or multiple CCDs are used. The detector coordinate system describes a single pixel raster of "unbinned" CCD pixels into which the multiple CCD/amplifier pixels are mapped to make a single, simple picture. It is used for displaying (and possibly processing) multiple amplifier/multiple CCD data in a consistent fashion with offsets, flips and transposes between the image pixels accounted for.
Dx = DTM1_1 * Cx + DTM1_2 * Cy + DTV1
Dy = DTM2_1 * Cx + DTM2_2 * Cy + DTV2
Cx = ( DTM2_2 * (Dx - DTV1) - DTM1_2 * (Dy - DTV2)) / (DTM1_1 * DTM2_2 - DTM1_2 * DTM2_1)
Cy = (-DTM2_1 * (Dx - DTV1) + DTM1_1 * (Dy - DTV2)) / (DTM1_1 * DTM2_2 - DTM1_2 * DTM2_1)
See the NOAO website for more details.
DTM2_2 1.0000000Detector transform matrix
DTV1 0.0000000 Detector transformation vector
DTV2 96.0000000 Detector transformation vector
EPOCH 2000.0 same as EQUINOX (for back compat.)
EQUINOX 2000.0 equinox of RA and Dec
EXPTIME 1200. actual integration time, seconds
EXTEND FFile has no extensions
FILENAME 'SPEC/2004.0413/F2.20.bg_1.0420'Name of one of original FITS files Multiple exposures were combined to make the image from which this spectrum was extracted. See IMCMBnnn below.
GAIN 2.0000000 Gain, electrons per ADU
HA '+00:59:34.248 ' hour angle
IMAGEID '1' Amplifier ID
IMAGETYP 'OBJECT ' object, flat, bias, etc.
INSFOCUS '0.86995 ' instrument focus
INSTAZ '0.00000000 ' instrument azimuth offset(arcsec)
INSTEL '0.00000000 ' instrument elevation offset(arcsec)
INSTRUME 'spec ' instrument name
IRAF-TLM '16:16:11 (31/08/2004)'Time of last IRAF modification
LTM1_1 1.0000000Image transform matrix The image coordinate system (Ic,Il) refers to the recorded image pixel array. The image array may include other information such as overscan and prescan. Thus the actual data pixels from the CCD may occupy only a region of the image. However the image coordinate system begins with (1,1) for the first pixel in the image. The first data pixel will begin with some coordinate (Ic1,Il1). The data pixels then increment by one for each "binned" pixel. As with the amplifier coordinate system the general linear coordinate transformation between the CCD and image coordinates is given by
Ic = LTM1_1 * Cx + LTM1_2 * Cy + LTV1
Il = LTM2_1 * Cx + LTM2_2 * Cy + LTV2
Cx = ( LTM2_2 * (Ic - LTV1) - LTM1_2 * (Il - LTV2)) / (LTM1_1 * LTM2_2 - LTM1_2 * LTM2_1)
Cy = (-LTM2_1 * (Ic - LTV1) + LTM1_1 * (Il - LTV2)) / (LTM1_1 * LTM2_2 - LTM1_2 * LTM2_1)
LTM2_2 1.0000000Image transform matrix
MJD 53108.17833 modified Julian Date of start of exposure
NAMPS 4Number of amplifiers reading from detectors
NAXIS 2Number of axes
NAXIS1 4505Axis lengthdispersion axis
NAXIS2 3Axis length1=spectrum, 2=sky+spectrum,3=sky
NSCANROW 1 number of CCD rows scanned
OBJECT 'F2.20.bg 1 306' Name of the object observed, added from APID[APERTURE]
OBSERVAT 'mmto ' observatoryIRAF abbreviation
OBSERVER 'dgf, nc, mk, mc ' observers
ORIGIN 'NOAO-IRAF FITS Image Kernel December 2001'FITS file originator
ORIGSEC '[1:1024,1:4608]'First amplifier limits in pixels
PARANGLE '80.7628085 ' telescope parallactic angle(degrees)
PI 'dgf ' Principal Investigator
POSANGLE 70.486 telescope position angle
PROPID 'Engineering ' observing proposal ID
RA '9:21:03.218' right ascension (hh:mm:ss)
RDNOISE 5.0000000 Noise, electrons
ROTANGLE '10.27660791 ' rotation angle, degrees
SECPIX1 0.0800000 Arc-seconds per pixelAt center of image along first (dispersion) axis
SERIALID '8351-7-5'
SIMPLE TFits standard
ST '10:20:01.041 ' sidereal time of start of exposure
TELESCOP 'mmt_f5_adc ' telescope name
TELFOCUS '15057.350 ' telescope focus
TILTPOS '-1.92600 ' tilt position
UT '04:16:47 ' universal time of start of exposure
VDD 14.9080000 HK value for CCD controller
VODL 19.8660000 HK value for CCD controller
VOG1 -5.9130000 HK value for CCD controller
VOG2 -4.9260000 HK value for CCD controller
VRGlo -8.8860000 HK value for CCD controller
VRGhi 2.9930000 HK value for CCD controller
VSlo -7.8950000 HK value for CCD controller
VShi 1.9850000 HK value for CCD controller
VPlo -8.8870000 HK value for CCD controller
VPhi 0.9920000 HK value for CCD controller
VRD 7.9710000 HK value for CCD controller
VTemp -119.8200000 HK value for CCD controller

The following keywords are added by image data reduction tasks:

APERTURE 125Aperture number (sequential on detector)
APIDnnn'130628 08:40:8.9450 45:30:59.9170 0 42 184.462 155.069' Catalog_number RA Dec -5000=TOI/0=program fiber xfib yfib
APNUMnnn '125 0 125 125' Aperture 0=sky/2=nonsky Aperture Aperture
APRANGE '0:0 ' meaningless
BCV -27.0360641479492 Barycentric velocity correction in km/sec from rvsao.xcsao
BESTTEMP 'hemtemp0' Name of best cross-correlation template file from rvsao.xcsao
CATNAME 'name ' Name of catalog with fiber sky position
CATNUM 306Number of entry in catalog
CATOBJ 'target ' Name of object from catalog
CCDPROC Jul 16 12:34 CCD processing done
CD1_1 1.21003552397869 X-axis WCS units (Angstroms) per pixel
CD2_2 1 Y-axis WCS units (spectra) per pixel
CDELT1 1.21003552397869 X-axis WCS units (anstroms) per pixel
CDELT2 1. X-axis WCS units (anstroms) per pixel
COMMENTTemplate information from rvsao.xcsao:
COMMENTfile name, cross-correlation velocity, error, R-value
COMMENTcorrelation peak height (0-1) and width (km/sec)
COMMENTvelocity relative to template, template BCV
COMMENTtemplate em. chopped, template filtered
COMMENTEmission line information from rvsao.emsao:
COMMENTline name, rest wavelength, observed wavelength
COMMENTline height, line width, redshift (km/sec), redshift error (km/sec)
COMMENTequivalent width, weighting factor
CRPIX1 1. X-axis WCS (wavelength) reference pixel
CRVAL1 3700. WCS (wavelength) value at X-axis reference pixel
CTYPE1 'LINEAR ' X-axis WCS is linear
CTYPE2 'LINEAR ' Y-axis WCS is linear
CZEM 47328.7485072547 Emission line velocity in km/sec from rvsao.emsao
CZEMERR 16.2019607110046 Emission line velocity error in km/sec from rvsao.emsao
CZEMNL 10 Number of emission lines found by rvsao.emsao
CZEMNLF 8 Number of emission lines fit by rvsao.emsao
CZERR 16.4119728769627 Redshift velocity error in km/sec
CZPARAMS '4 4096 1 5 10 100 200 0.05' rvsao.xcsao parameters: number of templates, number of log-wavelength pixels, zpad flag, 4 filter limits, apodization
CZXC 47328.0782493144 Best cross-correlation redshift velocity in km/sec from rvsao.xcsao
CZXCERR 7.30550220240955 Best cross-correlation redshift velocity error in km/sec from rvsao.xcsao
CZXCR 16.6141650060873 Best cross-correlation redshift R-value from rvsao.xcsao
DCLOG1 'REFSPEC1 = comp.ms' Reference wavelength calibration spectrum
DC-FLAG 0 Wavelength axis is linear, not log wavelength
DISPAXIS 1 Dispersion axis (1=X)
EMLINE1 'OII 3727.30 4316.45 152.06 2.8951 47386.15 14.56 1103.48 0.033'
EMLINE2 'Hg 4340.50 5025.82 44.999 2.1767 47334.41 35.10 245.52 0.006'
EMLINE3 'Hb 4861.33 5629.04 204.08 2.5295 47343.62 4.89 1293.98 0.288'
EMLINE4 'OIII 5006.84 5797.94 63.244 4.1075 47368.22 22.82 651.16 0.013'
EMLINE5 'OI 6300.23 7297.30 0.0000 0.0000 0.00 0.00 0.00 0.000'
EMLINE6 'N1 6548.06 3700.00 0.0000 0.0000 -130393.89 0.81 0.00 0.000'
EMLINE7 'Ha 6562.82 7599.53 637.70 2.8218 47357.47 6.96 4510.63 0.142'
EMLINE8 'N2 6583.57 7623.62 218.02 3.7515 47360.24 3.72 2050.23 0.497'
EMLINE9 'S1 6716.44 7777.02 92.506 2.7575 47339.64 28.91 639.41 0.008'
EMLINE10 'S2 6730.81 7794.29 84.108 2.4362 47367.40 22.78 513.61 0.013'
EMSAO 'rvsao.emsao 2.3.7 31-Aug-2004 16:16 CZEM = 47328.75 LINES = 8'
END
FIBRGEOM2004-Jul-16 16:35 geometric correction madeWritten by hectospec.htran
FIBRTRAN2004-Jul-16 16:35 fiber throughput corrected: 10 order spline3Written by hectospec.htran
FIBRFILE 'tpc_dome.ms' File used for throughput correction
FIELD 'F2.20.bg_1' Name of field which includes this object
FIBER 248Fiber number
FIBER_X 49.148Fiber X coordinate on focal plane
FIBER_Y -151.72Fiber Y coordinate on focal plane
FIXPIX Jul 16 12:34 Fix mscdb$sao/mmto/mmt/spec/badpix1.pl + sat + bleed
GAINCORR 1.Gain correction in CCDPROC
HABSKY '2004-Aug-30 16:06 hectospec$lib/skyabs.fits divided out'Added by hectospec.habsky
HEXTRACT '2004-Jul-16 16:31 extracted from F2.20.bg_1.fits'Written by hectospec.hextract
HEXAPREF 'dome ' Aperature reference file used by HEXTRACT
HEXAPMAP 'F2.20.bg_1_map'Aperture map file used by HEXTRACT
HMERGE 2004-Jul-16 13:31 4 amplifiers merged into one imageWritten by hectospec.hmerge task
HISTORYrvsao.sumspec 2.3.5 run 16-Jul-2004 16:32
HNORM 2004-Jul-16 16:30 pixels normalized by flat.fitsWritten by hectospec.hnorm task
HPROC2004-Jul-16 12:34 fixpix, overscan, and trimHPROC output
IMCMB001 'F2.20.bg_1.0420.fits[1]' HCOMBINE first image
IMCMB002 'F2.20.bg_1.0422.fits[1]' HCOMBINE second image
IMCMB003 'F2.20.bg_1.0424.fits[1]' HCOMBINE third image
INTERP 'wavelength interpolated '
JD 2453108.685266Julian date of observation midtime
LJD 2453108.Integer Julian Date
NCOMBINE 3 Number of images combined
NP1 1 First X pixel to which WCS applies
NSKYFIB 5 Number of sky fibers used by hectospec.skyproc
NSKYMAX 5 Maximum number of sky fibers usable by hectospec.skyproc
OVERSCANJul 16 12:34 Overscan is [1080:1120,3:4610], mean 2490.28
PREAMPFX2004-Jul-16 12:34 preamplifier correction madeHPROC output
QPLOT 'rvsao.xcsao 2.3.5 16-Jul-2004 17:45 VELOCITY = 47430.28 Q = Q'
SKYDIST 0 If nonzero, only use fibers closer than this in focal plane
SKYFIB '244_267_279_264_222_'Sky fibers used for background removal
SKYAPER '27+28+104+114+143'Sky apertures used for background removal
SKYCERT 4 Maximim R-value for skies correlated against template for hectospec.skyproc
SKYMETHD 'SKYSUB ' Sky subtraction method is hectospec.skyproc
SKYRATIO 0.970260 Scale factor from object sky lines to mean sky lines in hectospec.skyproc
SKYSTDLM 0.2 Reject sky spectra with RMS > 0.2 from mean sky RMS in hectospec.skyproc
SPECNUM 125Number of spectrum in extracted 2-D file
TRIM Jul 16 12:34 Trim is [51:1074,3:4610]
TDEC '+30:31:02.74'Declination of optical axis
TEPOCH 2000Equinox of optical axis (J assumed)
TRA '+09:20:11.36'Right ascension of optical axis
TYPE ' '
VELOCITY 47328.1914967525 Best redshift velocity in km/sec
VELQUAL '_ ' Velocity quality (_=not set, Q=good, X=bad, ?=uncertain) from rvsao.qplot
WAT0_001'system=equispec' IRAF WCS
WAT1_001'wtype=linear label=Wavelength units=angstroms'IRAF WCS
WAT2_001 'wtype=linear' IRAF WCS
WCSDIM 2 Number of WCS dimensions
XCTEMP1 'hemtemp0 47328.078 7.306 16.6142 0.661 172.065 47358.835 0.000 0 3'
XCTEMP2 'habtemp90 47390.822 95.386 2.73766 0.193 481.738 57253.165 0.000 0 3'
XCTEMP3 'femtemp97 47329.947 8.079 16.0382 0.666 184.104 47361.315 0.000 0 3'
XCTEMP4 'fabtemp97 47504.457 114.344 2.17596 0.177 475.139 47534.421 0.000 0 '
XCSAO 'rvsao.xcsao 2.3.7 30-Aug-2004 16:41 CZXC = 47328.08 R = 16.61'