In FU Ori type outbursts, driven by episodic accretion, the stellar luminosity can temporarily increase by orders of maximum. This ProDiMo model (Rab+2020) is a time-dependent simulation of the chemical processes that might occur in the outbursting source such as V883 Ori. The top left figure shows the CO concentration in the disk as a function of radius and height. The three other plots show simulated ALMA CO-observations for different inclination angles. We see that the CO ice is quickly sublimated at the onset of the outburst, leading to high CO concentrations almost everywhere in the disk, followed by a much slower re-formation of the CO ice, connected to a decline of the CO signal.The effect is limited to about the innermost 2000 au.
