A correction for IUE UV fluxes
to make them consistent with the HST UV calibration

Reference: Bohlin, R., and Bianchi, L. 2018, A.J., 155, 162 ; arXiv : 1802.03419
A Correction for IUE UV Flux Distributions from Comparisons with CALSPEC
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A collection of spectral energy distributions (SEDs) is available in the Hubble Space Telescope (HST) CALSPEC database that is based on calculated model atmospheres for pure hydrogen white dwarfs (WDs). A much larger set (about 100,000) of UV SEDs covering the range (1150-3350 Ang) with somewhat lower quality are available in the IUE database. IUE low-dispersion flux distributions are compared with CALSPEC to provide a correction that places IUE fluxes on the CALSPEC scale. While IUE observations are repeatable to only 4–10% in regions of good sensitivity, the average flux corrections have a precision of 2–3%. Our re-calibration places the IUE flux scale on the current UV reference standard and is relevant for any project based on IUE archival data, including our planned comparison of GALEX to the corrected IUE fluxes. IUE SEDs may be used to plan observations and cross-calibrate data from future missions, so the IUE flux calibration must be consistent with HST instrumental calibrations to the best possible precision.

Tables with the combined IUE spectra of CALSPEC stars, and the IUE flux corrections:

Table 2. The correction factors for IUE fluxes

Combined IUE spectra for CALSPEC stars:

g191b2b.mrg

gd153.mrg

gd71.mrg

grw_70d5824.mrg

hz21.mrg

hz43

These tables are also available at :
MAST HLSP
and
VizieR On-line Data Catalog: J/AJ/155/162