The purpose of the study reported here was to check if the glitch removal process included in Derive-SPD has an impact on spectral lines detected in fast speed AOT 1 observations. The spectra of three Planetary Nebulae with strong emission lines were selected for this test.
The following steps were followed:
The attached figures show several examples of the comparison between the standard AAR product (crosses) and the non-deglitched AAR (asterisks).
Figure 8.3: Good AOT 1 line fitting
Figure 8.4: Bad AOT 1 line fitting
Table 8.1 displays the results of the line flux calculation after a Gaussian fit, for all those lines in the three observations in which points flagged as glitched were found.
|Source||Line||Line flux||Line flux||%|
|( )||standard AAR||non-deglitched AAR||discrepancy|
|(W cm )||(W cm )|
The results of the analysis are:
Generally the spectrum resulting from a fast speed AOT 1 observation is improved after glitch removal. However, when points belonging to spectral lines are flagged as glitched, one must be cautious about the line profiles and fluxes (except for band 4) because the line profile may be significantly distorted by glitch removal.
If a user wants to derive line fluxes from fast AOT 1's it will be necessary to check the datapoints around a line to see if they are flagged as glitched. If they are it may be necessary to visit one of the data centers so that additional data processing can occur.