Thesis Meeting

Met with Kim and Chris at long last this afternoon. The last time we all met was in April, and while I’ve gone to Kim a couple times with questions in the interim, it was good to meet with both of them and talk about my thesis again.

We talked a bit about my troubles with the deadtime correction with the Crab data. We’re not convinced that the Crab is the right source to be using, and Chris is going to e-mail another scientist to see if he has suggestions for better galatic sources to use. Unfortunately, those sources are still likely to require deadtime corrections. We also grabbed another scientist in the lab, Craig, who has done a lot of work with XTE data, and he was able to answer a few questions about the deadtime correction.

One interesting thing that came out of our talk with Craig was that XTE Epoch 5 does not correspond with a gain change, but with PCU 0 blowing it’s propane layer. This means that during Epoch 5, even though PCU 0 is still generating data, it may not have the spectral response that we are expecting, and may not be well-modelled. This means that I will have to go back and re-extract the Epoch 5 data for both the Crab and MCG -6-30-15 with PCU 0 excluded.

We also talked a bit about my work with the pipeline results. Unfortunately, it looks like the blind-fitting results are not coming back as reasonable. This is a problem because if I start to “massage” the spectral fits, our own biases can be easily introduced. We’d really like to say that blind fitting returns reasonable results, but they don’t, and this is largely because the bandpass of XTE and the degeneracies of the reflection models are working against each other.

At least I have a few directions to go in right now, and I’m looking forward, once again, to my thesis work over the next few weeks.