On conductor submonoids of factorial monoids

We study algebraic and arithmetic properties of submonoids (resp. subrings) of factorial monoids (resp. factorial domains) whose non-invertible elements all lie in the conductor. This continues earlier work of Baeth, Cisto, et al… On our way we answer several conjectures, formulated in their papers in the affirmative ([1,Conjecture 4.16] and [6, Conjectures 2.3 and 2.10, and Section 9]).