Cause of the lack of PAH feedback in regions intersected by the southern outflow

Determine whether the observed absence of significant changes in PAH ionization state and grain size in regions intersected by the southern outflow of NGC 3256 is caused by projection effects of the outflow crossing the galaxy disk or by a co-spatial outflow that does not alter PAH grains.

Background

The authors analyze PAH fluxes and PAH 6.2/7.7 and 11.3/7.7 ratios across the disk and within the outflow regions. They find no clear signs that the outflows significantly reduce PAH surface brightness or alter the average PAH ionization state or grain size compared to the rest of the disk.

Given the complex geometry of the merging system, it remains unresolved whether this lack of PAH modification arises from the outflow merely crossing the disk in projection or from a truly co-spatial outflow that is intrinsically unable to modify PAH grains.