Suggestion for extra "2D histograms" plots for online results

I think it would be useful to have the following 2D plots in the "2D histograms" section of the summary pages for online events:

• Under "Spins", add redshifted total mass on the x-axis, \chi_{\rm eff} on the y-axis. This helps me gauge how much a high-mass event falls outside the PyCBC search space, whose high-mass boundary typically follows a curve in this particular projection.
• Under "Location", add the sky position (ra on the x-axis, dec on the y-axis). I know the skymap is already shown, but having the scatter plot in addition to the smoothed/binned version is also useful, especially when the skymap is very precise or very degenerate.
• Under "Location", or perhaps a new section "Timing", add the arrival times at pairs of H1, L1, V1 detectors (or arrival time differences, as requested in #267 (closed)).