My Summer as a NASA Intern

Week 8

This week, I finished the last step of the cross-calibration analysis, which was finding cross-normalization constants. To do that, I updated another XSPEC script that my mentor wrote, and I created a Python program that would again write a new version of the script for each observatory pair. Each XSPEC program fits all the data in a given pair simultaneously and records the flux from each instrument. I then calculated the cross-normalization constant of each instrument pair by comparing the flux of one instrument to another.

The cross normalization constants for 2015 between NuSTAR and the other instruments.

While I was finishing up, my mentor and I noticed that the Swift data seemed very off. It was not following the expected trends very well, and it would measure vastly different fluxes for 3C 273 when compared to the other observatories. I tried to correct the Swift data by selecting different source and background regions for its extraction, but it did not seem to fix the glaring inconsistencies in the data.

Messed up contour plot showing how different the flux is between Swift and NuSTAR (from 2016).

Once I had finally found my cross-normalization constants, I began working on my final presentation. On Friday, I gave a short 5-minute presentation to the CRESST interns at NASA. Because I worked on fixing the Swift data for so long, I didn’t give myself enough time to prepare the presentation, and I kind of bombed it. Next week, I will be presenting again at a different event, so I’m hoping to do much better then!