HETGS Line Profiles

Verification with Real HETG Dataset

Verification: Capella HETG/ACIS-S (ObsID: 1103) dataset

Finally we verify the validity of the LSF library with the real science dataset. In this example we use a 43 ksec Calibration/GTO observation of Capella (ObsID 1103) taken with Chandra HETG/ACIS-S.

Similar to the earlier validation, we use isis to perform line profile fitting (using a delta function) here. Since the Capella spectrum exhibits a weak continuum, we add a 1st order polynomial function to adjust the baseline.

Since the plots themselves speak a thousand word, please look at the fitting results shown in the following figures.

Line Profile Fitting

HETG/ACIS-S +1st order spectra:

Fe XVII $\bf{\lambda{15.015}}$

Figure 11: Results of line profile fitting at Fe XVII. A delta function (forward-folded with both RMF and ARF) is used to fit the line. The red line shows the best-fit model. The difference $\delta\chi$ is also displayed for your entertainment: (top) HEG; (bottom) MEG.

Mg XII $\bf{\lambda{8.421}}$

Figure 12: The same as for Figure 11.

Si XIII Triplet $\bf{\lambda\lambda{6.647, 6.685, 6.740}}$

Figure 13: The same as for Figure 11.

Fe XVII + Ne X Blend $\bf{\lambda\lambda{12.125, 12.136}}$

Figure 14: The same as for Figure 11.

HETG/ACIS-S -1st order spectra:

Fe XVII $\bf{\lambda{15.015}}$

Figure 15: Results of line profile fitting at Fe XVII. A delta function (forward-folded with both RMF and ARF) is used to fit the line. The red line shows the best-fit model. The difference $\delta\chi$ is also displayed for your entertainment: (top) HEG; (bottom) MEG.

Mg XII $\bf{\lambda{8.421}}$

Figure 16: The same as for Figure 11.

Si XIII Triplet $\bf{\lambda\lambda{6.647, 6.685, 6.740}}$

Figure 17: The same as for Figure 11.

Fe XVII + Ne X Blend $\bf{\lambda\lambda{12.125, 12.136}}$

Figure 18: The same as for Figure 11.

These results of line fitting are quite representative of line profile analyses we have performed on other lines in the same dataset. A couple of spot checks on flux estimate also show that the measured fluxes do not depend on a full width that is used to extract line spectra here.

This demonstrates that the new LSF library is valid for extensive spectroscopic analysis.

Previous: Validation: Wavelength Next: New vs. Old RMFs (LSFPARMS vs. gRMF N0004)

This page was last updated Apr 11, 2003 by Bish K. Ishibashi. To comment on it or the material presented here, send email to bish@space.mit.edu.