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FUSE FITS Keywords

References and comments on FITS keywords are listed below. See main page for background.

Keyword Reference(s) Comments/Notes
EXTNAME See FITS standards document FITS convention for naming table extension (i.e., 'spectral container')
EQUINOX from EQUINOX keyword, see Dixon et al 2007, PASP, 119, 527 Comments here
RADECSYS HST Guide Star Catalog (Lasker et al. 1990, AJ, 99, 2019) Comments here
TIMESYS Dixon et al. 2007, PASP, 119, 527 UTC Time system
MJDREF 0.00000 [d] MJD zero point for times
SPECSYS Dixon et al. 2007, PASP, 199, 527 Heliocentric reference frame
VOSEGT 'SPECTRUM' Segment type
DATALEN derived from data [ ] Number of points in spectrum
DSSOURCE 'POINTED' Survey or Pointed
DATE from PROCDATE keyword Processing-Creation Date
VODATE from IDL "today" command Curation Date
VOREF '' URL for this Documentation
DS_IDENT 'ads/sa.fuse#a088010100000nvo4ttagfcal' Data Set Identifier
VERSION '1.0' Processing Version
COLLECT 'FUSE/FUV' Data Set Collection
INSTRUME from INSTRUME keyword Instrument
FILENAME derived from FILENAME keyword File Name
CR_IDENT derived from FILENAME keyword Internal dataset ID
CRETYPE 'Archival' Not an on-the-fly dataset
VOPUB 'MAST' VO Publishing Authority
AUTHOR 'FUSE project' Creator
VOPUBID 'ivo://' URI for VO Publisher
VOVER '1.0' VO Curation version
VORIGHTS 'PUBLIC' Data is public
CONTRIB1 from PRGRM_ID keyword. See Program ID
CONTACT 'archive help desk' general help desk
EMAIL '' Send questions here
OBJECT from FUSE keyword TARGNAME proposer's target name
SRCCLASS derived from OBJCLASS keyword Object Class
SRTYPE from SP_TYPE keyword Spectral Type
REDSHIFT from Z keyword [ ] Target redshift. If unknown, no value was listed in file.
VRAD_OBS derived from Z keyword. This value was supplied by the program GO and hence has an uncertain origin and reference frame. [km/s] Radial velocity
TITLE derived from data set name and target name Program Identification
RA_TARG from RA_TARG keyword [deg] right ascension of target
DEC_TARG from DEC_TARG keyword [deg] declination of target
WCS Paper 3 Keywords
1S2_1 'WAVE' Column name with spectral coordinates
1CYTP2 'WAVE-TAB' Spectral coordinate is wavelength
1S3_1 'WAVE' Column name with spectral coordinates
1CYTP3 'WAVE-TAB' Spectral coordinate is wavelength
RA from RA_TARG keyword [deg] project-defined right ascension
DEC from DEC_TARG keyword [deg] project-defined declination
APERTURE derived from APERTURE keyword. See FUSE Observer's Guide Sect. 2.3 [arcsec] radius or lengthxwidth LWRS (30x30, MDRS (4x20), HIRS (1.25x20, seldom used), pinhole: (0.5, seldom used)
DATE-OBS derived from TIMEOBS and DATEOBS keywords UT observation start time
EXPOSURE from OBSTIME keyword [s] eff. exposure duration
TSTART from OBSSTART keyword [d] MJD exposure start time
TSTOP from OBSEND keyword [d] MJD exposure stop time
TMID derived from OBSSTART and OBSEND keywords [d] MJD exposure mid time
SPECSDIM '1.0E-10 L' Comments here
SPEC_CAL Calibrated spectral coordinate
SPEC_ERR Dixon et al. 2007, PASP, 119, 527 section 5.1 quotes a value of 0.15 Angstroms; 42 km/sec at 1100 Angstroms as an upper limit for the typically used LWRS aperture. Since this may be interpreted as a 3-sigma value (J. Kruk, priv. commun., 2007) MAST gives 14 km/sec 14 km/s Wavelength statistical error
SPECBAND See for defining wavelength regions Spectral Band(s)
SPEC_VAL derived value [angstrom] Mean Wavelength
SPEC_BW derived value [angstrom] Bandpass Width Wmax - Wmin
SPEC_FIL nvo merged spectra are continuous 1.0 No gaps between points
SPEC_RP FUSE Observer's Guide Sect. 2.4.3 Resolving power W/dW 20,000 (LWRS aperture) but depends on detector segment (e.g., lower for LIF 2B)
FLUXSDIM '1.0E+7 ML-1T-3' Comments here
FLUX_CAL Calibrated Fluxes
SYS_ERR Van Dixon, private communication [ ] flux sys error typically 5-10 percent
DER_SNR Stoehr et al. 2007 Space Tele. Coord. Fac. NL, 42, 4 [ ] Derived signal-to-noise ratio
FLUXAVG derived from data [erg/cm**2/s/angstrom] Average Flux
FLUXMAX2 derived from data [erg/cm**2/s/angstrom] 98% Maximum Flux
SPECDISP derived from data ((Wmax-Wmin)/npts) [angstrom/pixel] Dispersion