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Final Datasets for WD1957+225

Dataset Range Texp MJD QF
E140M-1425_020X020_52021 FITS ETC 1140-1729 5167 52021.664 98

Notes. Range is in Å. Texp is maximum monochromatic exposure (seconds), accounting for coadditions and splices. MJD is first start date of a sequence. "QF" is a quality factor (0-100).

Preview. In main panel, first spectrum is blue and its photometric error (2σ) red. For additional spectra, second is green and its photometric error orange; third is black, and color coding repeats for n>3. Only first two error curves are shown. Flux density and error tracings were heavily smoothed for display. Fluxes are clipped at photometric error. For weak spectra, error tracing dominates. Highly structured error curve tracks rapidly varying "echelle ripple" sensitivity.

Right panel depicts observation time line. Each exposure start is marked by a vertical bar spanning λ range of mode (bottom of frame is 1000 Å; top, 3300 Å). Gray shading delimits FUV modes; upper unshaded zone, NUV. Color coding: orange E140M, blue E140H, green E230M, red E230H.

Data table. Dataset column drills down to next layer: contributing exposures. Bottom-most level: o-type subexposures (if n>1). FITS returns FITS file containing data products. EXTEN=0 is header describing target, observation, and processing history (if applicable). EXTEN=1 holds wavelength, flux, photometric error, and data quality flag. If dataset is o-type with two or more subexposures, EXTEN=1 is coadded spectrum, subexp 1 is in EXTEN=2, subexp 2 in EXTEN=3, and so forth.

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