2025 Spring Lab Notebook

2.19

Working on paper figures. Concern that the plots we made for the 1000 image sequence are dominated by drift from the source separation in a given pair of beams. Some example plots of this are below.

Open

Open

The red line is temperature and the blue is source separation, for different pairs of beams. We want to compute a running mean for this data and subtract it for all source separation values before taking our standard deviation.

The computed running mean with a window of 20 points is shown in the figure above. We now take this mean and subtract from the y source separation values for beam pair 0.

The new plot looks relatively similar to the previous 1000 image plot (shown below); the x pairs are much flatter

Old plot:

Elana also had the idea to compare this with the ellipticity of our first batch of on-sky data points, so we can make a stronger argument that this dome seeing is directional.

Procedure

• Galsim, make a box around each star to find the PSF

• Rotate the ellipticity back around into the correct x,y frame

  • Coordinate transformation is the same as before to figure out the major/minor axes