Disentangling the entangled: Observations and analysis of the triple non-coeval protostellar system VLA1623

TL;DR

This study analyzes the youngest multiple protostellar system VLA1623, revealing it as a triple non-coeval system with a potential Keplerian disk around the Class 0 protostar VLA1623A, offering insights into early star formation stages.

Contribution

First detailed observational analysis of VLA1623 as a triple non-coeval protostellar system with evidence of a Keplerian disk around a Class 0 protostar.

Findings

VLA1623 is a triple non-coeval system with distinct evolutionary stages.

Detection of a potential Keplerian disk around VLA1623A.

VLA1623B identified as an extremely young protostar.

Abstract

Commonplace at every evolutionary stage, Multiple Protostellar Systems (MPSs) are thought to be formed through fragmentation, but it is unclear when and how. The youngest MPSs, which have not yet undergone much evolution, provide important constraints to this question. It is then of interest to disentangle early stage MPSs. In this letter we present the results of our work on VLA1623 using our observations and archival data from the Submillimeter Array (SMA). Our continuum and line observations trace VLA1623's components, outflow and envelope, revealing unexpected characteristics. We construct the SED for each component using the results of our work and data from literature, as well as derive physical parameters from continuum and perform a simple kinematical analysis of the circumstellar material. Our results show VLA1623 to be a triple non-coeval system composed of VLA1623A, B & W, with each source driving its own outflow and unevenly distributed circumstellar material. From the SED, physical parameters and IR emission we conclude that VLA1623A & W are Class 0 and I protostars, respectively, and together drive the bulk of the observed outflow. Furthermore, we find two surprising results, first the presence of a rotating disk-like structure about VLA1623A with indications of pure Keplerian rotation, which, if real, would make it one of the first evidence of Keplerian disk structures around Class 0 protostars. Second, we find VLA1623B to be a bonafide extremely young protostellar object between the starless core and Class 0 stages.