  Galaxy imaging surveys provide us with information on both the galaxy
distribution and their shapes. In this paper, we systematically investigate the
sensitivity of galaxy shapes to new physics in the initial conditions. For this
purpose, we decompose the galaxy shape function into spin components, and
compute the contributions to each spin component from both intrinsic alignment
and weak lensing. We then consider the angular-dependent primordial
non-Gaussianity, which is generated by a non-zero integer spin particle when
active during inflation, and show that a galaxy imaging survey essentially
functions as a spin-sensitive detector of such particles in the early universe.
We also perform a forecast of the PNG generated from a higher spin particle,
considering a Rubin Observatory LSST-like galaxy survey.
