Related Experiment Video
Updated: Jul 26, 2025

Scattering And Absorption of Light in Planetary Regoliths
Published on: July 1, 2019
Streamers feeding the SVS13-A protobinary system: astrochemistry reveals accretion shocks?
Eleonora Bianchi1, Ana López-Sepulcre2,3, Cecilia Ceccarelli2
1Excellence Cluster ORIGINS, Boltzmannstraße 2, Garching bei München, 85748, Germany. eleonora.bianchi@origins-cluster.de.
Abstract:
We report Atacama Large Millimeter/submillimeter Array (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 shows an additional emitting component spatially coincident with the dust-accretion streamer, at a distance ≥120 au from the protostars, and at blue-shifted velocities (>3 km s-1 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 energy (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.
Related Concept Videos
Sulfur Assimilation
Atomic Emission Spectroscopy: Interference
Atomic Emission Spectroscopy: Overview
Atomic Emission Spectroscopy: Instrumentation
Second Order systems II
Second Order systems I
By reinterpreting the system, one can derive the closed-loop transfer function, which...

