  We report ALMA high-angular resolution (~ 50 au) observations of the binary
system SVS13-A. More specifically, we analyse deuterated water (HDO) and sulfur
dioxide (SO2) emission. The molecular emission is associated with both the
components of the binary system, VLA4A and VLA4B. The spatial distribution is
compared to that of formamide (NH2CHO), previously analysed in the system.
Deuterated water reveals an additional emitting component spatially coincident
with the dust accretion streamer, at a distance larger than 120 au from the
protostars, and at blue-shifted velocities (> 3 km/s from the systemic
velocities). We investigate the origin of the molecular emission in the
streamer, in light of thermal sublimation temperatures calculated using updated
binding energies (BE) distributions. We propose that the observed emission is
produced by an accretion shock at the interface between the accretion streamer
and the disk of VLA4A. Thermal desorption is not completely excluded in case
the source is actively experiencing an accretion burst.
