psphot Galaxy Parameter Measurements

For PV3 we plan to add some additional measurements of extended sources in psphotStack. This note describes these measurements and includes some results from a test on the SAS2 region.

Asymmetry Indices

In Section 5.6 of a paper published in 2002 ​Luc Simard et al. described two measurements for use in the morphological classification of galaxies (see section 5.6).

The measurements are performed on residual images created by subtracting model fits of galaxies from images.

A later paper published in 2011 shows results of a study on ​SDSS images.