DS test  

DS6.1x test.

 

DS6.1x Test Report

This is a validation test of DS 6.11 after the J. Davis fix on the wavelength scale problem (in tg_resolve_events). In brief, the wavelength scale problem is no longer outstanding, while other geometrical issues (mostly related to LETG) may still remain unresolved.

LETG + HRC-S:

A MARX simulated LETG+HRC-S dataset is processed with DS6.10 and DS6.11. The resulted plots speak themselves about the improvement.

LETG/HRCS +1st order
LETG/HRCS +1st order
Figure 1: Wavelength vs. Wavelength Offset plot for a LETG+HRC-S +1st order configuration: (top) processed with DS6.10 and (bottom) DS6.11. Each bar marker (not error bar, btw) indicates the centroid position for the offset distribution at that bin.

Look closer to the bar markers.

LETG/HRCS +1st order (marker only)
LETG/HRCS +1st order (marker only)
Figure 2: Wavelength vs. Wavelength Offset plot for a LETG+HRC-S +1st order configuration: (top) processed with DS6.10 and (bottom) DS6.11. The same data points as shown in Figure 1.

As J. Drake points out, there exists a constant offset (-0.005AA) in wavelength across HRC-S chips. The similar effect is also seen in the -1st order as well.

LETG/HRCS -1st order
LETG/HRCS -1st order
Figure 3: Wavelength vs. Wavelength Offset plot for a LETG+HRC-S -1st order configuration: (top) processed with DS6.10 and (bottom) DS6.11.

LETG/HRCS -1st order (marker only)
LETG/HRCS -1st order (marker only)
Figure 4: Wavelength vs. Wavelength Offset plot for a LETG+HRC-S -1st order configuration: (top) processed with DS6.10 and (bottom) DS6.11. The same data points as shown in Figure 3.

HETG + ACIS-S:

A MARX simulated HETG+ACIS-S dataset is processed with DS6.10 and DS6.11. The results are identical to that of LETG+ACIS-S.

HETG/ACIS-S +1st order
HETG/ACIS-S +1st order
Figure 5: Wavelength vs. Wavelength Offset plot for a HETG+ACIS-S +1st order configuration: (top) processed with DS6.10 and (bottom) DS6.11. Each bar marker (not error bar, btw) indicates the centroid position for the offset distribution at that bin.

Look closer to the bar markers.

HETG/ACIS-S +1st order (marker only)
HETG/ACIS-S +1st order (marker only)
Figure 6: Wavelength vs. Wavelength Offset plot for a HETG+ACIS-S +1st order configuration: (top) processed with DS6.10 and (bottom) DS6.11. The same data points as shown in Figure 5.

Notice the increasing trend in wavelength offset across a single ACIS CCD chip. We do not understand the cause of the tilt (actually one can spot the same effect in Jeremy's memo). The scale of this particular anomaly is much smaller than the absolute accraucy required for HETG in any case, however. The similar effect is also seen in the -1st order as well.

HETG/ACIS-S -1st order
HETG/ACIS-S -1st order
Figure 7: Wavelength vs. Wavelength Offset plot for a HETG+ACIS-S -1st order configuration: (top) processed with DS6.10 and (bottom) DS6.11.

HETG/ACIS-S -1st order (marker only)
HETG/ACIS-S -1st order (marker only)
Figure 8: Wavelength vs. Wavelength Offset plot for a HETG+ACIS-S -1st order configuration: (top) processed with DS6.10 and (bottom) DS6.11. The same data points as shown in Figure 7.

This page was last updated Feb 14, 2003 by Bish K. Ishibashi. To comment on it or the material presented here, send email to bish@space.mit.edu.
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