2010 July 27
Based on the legwork I’ve done, what arguments can we make about the feasibility of my thesis and how should I modify my plans to make them more realistic?
Emphasize gamma rays in Cyg X-3 work🔗
Even though I keep on getting emails about X-ray observations of Cyg X-3 I shouldn’t lose sight of the fact that the key novelty for our Cyg X-3 work is the recent detection of it in gamma rays by AGILE and Fermi (Tavani+ 2009, Fermi LAT Collaboration 2009). We’ll have near-continuous monitoring of X-3 from Fermi’s all-sky mapping activities, though I need to get a better handle on what that dataset will look like. I also need to think about what kind of radio/gamma variability correlations we might find. Geoff suggests that previous work on blazars should provide a good starting point — say, things building on Maraschi+ 1992. For instance, the Fermi team was only able to constrain the delay between radio/gamma emission peaks as 5 +- 7 days — can we do better?
Emphasize gal90 as part of AGCTS🔗
We’re collecting data for the Cyg X-3 project in exactly the same way as we are for the AGCTS and we should make sure to emphasize that these data can be used for transient searching as well. The gal90 project data add to the AGCTS dataset:
- 5 pointings (including Kepler field)
- 164 scans at 3.14 GHz * 66 hours of data
- Mean duration of 0.40 hr
- Median duration of 0.325 hr
Which is nothing to sneeze at.
Explore Metrics for AGCTS🔗
From my attempts to compare the AGCTS and other existing surveys, and my attempts to apply existing measurements of transient rates to the expected AGCTS dataset, it’s become pretty clear that the transient parameter space is too large to allow one or two simple, definitive comparisons. I need to think about a few metrics for transient searches and rates that will demonstrate most clearly the way in which AGCTS is different than existing surveys and in which existing transient rate measurements apply (or fail to apply) to the AGCTS dataset.
The context for this point is that I had failed to appreciate how severely the move to higher frequencies affected the survey speed of the AGCTS. From my initial computations, I had expected it to work out to be clearly superior to the Hyman+ survey; now it’s pretty much inferior. Because of the different chunk of parameter space that we’re carving out, I think we still have interesting things to say about radio transients, but that perspective is definitely a shift in how I think about the AGCTS project.
Reference Posts🔗
There are a few smaller topics that I should write reference posts on:
- Characteristics of relevant radio transient surveys in the literature
- Transient rate measurements in the literature
- Summary of blazar gamma/radio correlation research and its potential applicability to Cyg X-3.