| 3 | | Gene suggested that the cupping may be an issue having to do with the S/N of the stack saturating to some value. To check this, I identified the four stars used earlier, added an additional star that appeared to have the core saturated, and then added four extra stars that probe a range of fainter magnitudes. The following table shows the peak values in the S^2^ image, the variance image, and the S^2 |
| | 3 | Gene suggested that the cupping may be an issue having to do with the S/N of the stack saturating to some value. To check this, I identified the four stars used earlier, added an additional star that appeared to have the core saturated, and then added four extra stars that probe a range of fainter magnitudes. The following table shows the peak values in the S^2^ image, the variance image, and the S^2^/V S/n image for these stars. The plot shows that as a function of the detection signal to noise (1 / PSF_INST_MAG_ERR), the stacks do seem to saturate at a S/N value lower than would be predicted based on the S/N values from the warp and chip image. |
