Modeling accretion shocks at the disk–envelope interface

As material from an infalling protostellar envelope hits the forming disk, accretion shock may develop which could (partially) alter entering disk. Observations with Atacama Large Millimeter/submillimeter Array (ALMA) indicate that emission originating warm SO and SO$_2$ might be good tracers of such shocks. The goal this work is to test under what conditions abundances gas-phase increase in at disk-envelope interface. Detailed models including gas dynamics are computed using Paris-Durham code for non-magnetized J-type shocks typical inner conditions. effect pre-shock density, velocity, strength ultraviolet (UV) radiation field on abundance explored. Warm chemistry efficient most considered. In lower-velocity (~3 km/s) shocks, increased through subsequent reactions starting thermally desorbed CH$_4$ toward H$_2$CO finally SO. higher velocity (>4 both formed OH atomic S. UV crucial particular formation photodissociation H$_2$O. Thermal desorption ice only relevant high-velocity (>5 high densities ($>10^7$ cm$^{-3}$). a possible tracer interface as long local present. Additional observations ALMA high-angular resolution provide further constraints. Moreover, James Webb Space Telescope will give access other slow, dense H$_2$, H$_2$O, [S I] 25$\mu$m.