Final Datasets for ALP-CEN-B
Notes. Spectral Range is in Å. Texp is maximum monochromatic exposure (in s), accounting for co-additions and splices. MJD is first start date of sequence. QF is quality factor (average S/N per resel).
Preview. In main panel (left), spectrum is blue and photometric error (1σ per resel) red. 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 is due to rapidly varying "echelle blaze."
Right panel depicts observation time line. Each exposure start is marked by vertical bar spanning wavelength range of mode (bottom of frame is 1000 Å; top, 3300 Å). Gray shading delimits FUV; upper unshaded zone, NUV. Color coding: E140M, E140H, E230M, E230H.
Data table. Dataset column drills down to next layer: contributing exposures. Bottom-most level: o-type sub-exposures. FITS returns .fits file containing data products. EXTEN=0 is header describing target, observation, and processing history. EXTEN=1 holds wavelength, flux, photometric error, and data quality flag. If dataset is o-type with two or more sub-exposures, EXTEN=1 is coadded spectrum, sub-exp 1 is in EXTEN=2, sub-exp 2 in EXTEN=3, and so forth. ETC returns flat-ASCII file designed for Exposure-Time Calculator adhering to STScI standards. Specially filtered ETC spectrum is NOT SUITABLE for analysis.