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 (you may download pdf here)
A Correction for IUE UV Flux Distributions from Comparisons with CALSPEC

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.

Table 2. The correction factors for IUE fluxes correction factors to bring IUE fluxes on the CALSPEC flux scale.

Combined IUE spectra for CALSPEC stars, from Bohlin and Bianchi 2018, A.J., 155, 162 ; arXiv:1802.03419 :

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