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Access to CALOBS data files
02 July 2001
CALOBS contains several versions of the ultraviolet (UV) and optical spectra of the fundamental flux standards used for HST calibrations. Some of these files contain the original data obtained from different sources (UV: VOYAGER2 or IUE; optical: Oke, Tapia or Stone; or STIS), while others contain corrected or updated versions. Updates to the flux distributions are indicated by file names with the same root name but incremental version number. The earlier versions are retained for comparison purposes. All files are in machine independent binary FITS table format. Information about the pedigree of a given spectrum is in the header of the FITS file, which can be read with the IRAF hedit task or by mrdfits.pro in IDL.
The table below lists the Oke's faint spectrophotometric standards. In total, Oke supplied 30 spectra, which include 5 more than his 1990 publication (Oke 1990). The CDBS name listed in column 4 of the table is the most recently updated version of the original Oke spectra on the white dwarf scale, corrected for spectral shape and absolute photometry, and covering the 3200 to 9200 Angstrom range. See Bohlin (1996) and references therein for details. The CDBS name listed in column 5 of the table is the most updated version of the IUE spectra on the white dwarf scale (see Bohlin 1996 for details). Those spectra have been used to create the CALSPEC spectra of HST standards and can also be used in the calibration of ground based data.
See Bohlin, Dickinson, and Calzetti (2001) for a description of the two most recent CALOBS additions: BPM16274_STIS_001 and G191B2B_PURE_STIS_001.
List of Oke's optical faint spectrophotometric standards:
NAME RA(2000) DECLINATION(2000) CDBS NAME CDBS NAME (1) (2) (3) (4) (5) G158-100 00 33 54.32 -12 07 57.1 G158_100_011 GD50 03 48 50.06 -00 58 30.4 GD50_013 GD50_012 SA95-42 03 53 43.67 -00 04 33.0 SA95_42_005 HZ 4 03 55 21.70 +09 47 18.7 HZ4_019 HZ4_018 LB227 04 09 28.76 +17 07 54.4 LB227_008 LB227_007 HZ 2 04 12 43.51 +11 51 50.4 HZ2_014 HZ2_013 G191B2B 05 05 30.62 +52 49 54.0 G191B2B_019 G191B2B_018 G193-74 07 53 27.40 +52 29 35.7 G193_74_008 BD+75D325 08 10 49.31 +74 57 57.5 BD_75D325_011 BD_75D325_010 AGK+81D266 09 21 19.06 +81 43 28.6 AGK_81D266_010 AGK_81D266_009 GD108 10 00 47.33 -07 33 31.2 GD108_012 GD108_011 FEIGE 34 10 39 36.71 +43 06 10.1 FEIGE34_020 FEIGE34_019 HD 93521 10 48 23.51 +37 34 12.8 HD93521_014 HD93521_013 HZ 21 12 13 56.42 +32 56 30.8 HZ21_015 HZ21_014 FEIGE 66 12 37 23.55 +25 04 00.3 FEIGE66_017 FEIGE66_016 FEIGE 67 12 41 51.83 +17 31 20.5 FEIGE67_016 FEIGE67_015 G60-54 13 00 09.53 +03 28 55.7 G60_54_007 HZ 44 13 23 35.37 +36 08 00.0 HZ44_018 HZ44_017 GRW+70D5824 13 38 51.77 +70 17 08.5 GRW_70D5824_012 GRW_70D5824_011 BD+33D2642 15 51 59.86 +32 56 54.8 BD_33D2642_016 BD_33D2642_015 G138-31 16 27 53.59 +09 12 24.5 G138_31_009 G24-9 20 13 56.05 +06 42 55.2 G24_9_009 LDS749B 21 32 15.75 +00 15 13.6 LDS749B_011 LDS749B_010 BD+28D4211 21 51 11.07 +28 51 51.8 BD_28D4211_021 BD_28D4211_020 G93-48 21 52 25.33 +02 23 24.3 G93_48_009 G93_48_008 BD+25D4655 21 59 39.3 +26 25 42 BD_25D4655_007 BD_25D4655_006 NGC 7293 22 29 38.46 -20 50 13.3 NGC7293_010 NGC7293_009 LTT 9491 23 19 34.98 -17 05 29.8 LTT9491_010 LTT9491_009 FEIGE 110 23 19 58.39 -05 09 56.1 FEIGE110_020 FEIGE110_019 GD 248 23 26 06.69 +16 00 21.4 GD248_010
Note: The unit of flux in all files is erg s-1 cm-2 A-1.
REFERENCES:
Bohlin, R.C., 1996, AJ, 111, 1743. Bohlin, R.C., Dickinson, M. E., & Calzettti, D. 2001, AJ, in press. Oke, J.B. 1990, AJ, 99, 1621.
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To the CALOBS data (historical data, for current and more accurate data, please go to the CALSPEC page)