The space distribution of nearby star-forming regions

TL;DR

High-precision radio interferometry enables accurate distance and motion measurements of nearby star-forming regions, enhancing our understanding of star formation processes and internal structures within 1 kpc of the Sun.

Contribution

This paper highlights the potential of VLBI techniques to precisely measure distances and motions of young stars, improving the study of star-forming regions.

Findings

Distances to Taurus, Ophiuchus, Perseus, and Orion measured with unprecedented accuracy.

Radio interferometry can determine internal structures and dynamics of star-forming regions.

Enhanced measurements will improve comparisons with theoretical models of star formation.

Abstract

Multi-epoch radio-interferometric observations of young stellar objects can be used to measure their displacement over the celestial sphere with a level of accuracy that currently cannot be attained at any other wavelength. In particular, the accuracy achieved using carefully calibrated, phase-referenced observations with Very Long Baseline Interferometers such as NRAO's Very Long Baseline Array is better than 50 micro-arcseconds. This is sufficient to measure the trigonometric parallax and the proper motion of any radio-emitting young star within several hundred parsecs of the Sun with an accuracy better than a few percent. Using that technique, the mean distances to Taurus, Ophiuchus, Perseus and Orion have already been measured to unprecedented accuracy. With improved telescopes and equipment, the distance to all star-forming regions within 1 kpc of the Sun and beyond, as well as their internal structure and dynamics could be determined. This would significantly improve our ability to compare the observational properties of young stellar objects with theoretical predictions, and would have a major impact on our understanding of low-mass star-formation.