Astrometry of Water Maser Sources in Nearby Molecular Clouds with VERA - II. SVS 13 in NGC 1333

TL;DR

This study uses VLBI astrometry to measure the distance to the NGC 1333 star-forming region with high precision, confirming previous estimates and providing detailed maser motion data.

Contribution

First high-precision VLBI parallax measurement of water masers in NGC 1333, improving distance accuracy and revealing maser associations with young stellar objects.

Findings

Distance to NGC 1333 is 235+/-18 pc, consistent with previous estimates.

Maser features are associated with VLA4A, a young stellar object.

Proper motions of masers are not clearly linked to jets or disks, requiring further study.

Abstract

We report on the results of multi-epoch VLBI observations with VERA (VLBI Exploration of Radio Astrometry) of the 22 GHz H2O masers associated with the young stellar object SVS 13 in the NGC 1333 region. We have carried out phase-referencing VLBI astrometry and measured an annual parallax of the maser features in SVS 13 of 4.25+/-0.32 mas, corresponding to the distance of 235+/-18 pc from the Sun. Our result is consistent with a photometric distance of 220 pc previously reported. Even though the maser features were detectable only for 6 months, the present results provide the distance to NGC 1333 with much higher accuracy than photometric methods. The absolute positions and proper motions have been derived, revealing that the H2O masers with the LSR (local standard of rest) velocities of 7-8 km s-1 are most likely associated with VLA4A, which is a radio counterpart of SVS 13. The origin of the observed proper motions of the maser features are currently difficult to attribute to either the jet or the rotating circumstellar disk associated with VLA4A, which should be investigated through future high-resolution astrometric observations of VLA4A and other radio sources in NGC 1333.