Classification of X-Ray Flare-driven Chemical Variability in Protoplanetary Disks

Young stars are highly variable in the X-ray regime. In particular, bright flares can substantially enhance ionization surrounding protoplanetary disk. Since disk chemical evolution is impacted by ionization, have potential to fundamentally alter chemistry of planet forming regions. We present 2D models that incorporate a stochastic flaring module, named \xgen, and examine flares' overall impact compared assume constant flux. 500 years events find global changes on both short time scales (days) response discrete long time-scales (centuries) cumulative many flares. Individual most strongly affect small gas-phase cations, where single flare temporarily abundance species such as H$_3^+$, HCO$^+$, CH$_3^+$, C$^+$. also drive out "steady state" over longer periods, disk-integrated some species, O O$_2$, few percent year model. explore whether specific history (randomly drawn but from same energy distribution) impacts it does not. Finally, we electron fraction. While molecules modeled not sensitive flares, certain including observable molecules, very reactive dynamic environment young star.