Tomography of Galactic star-forming regions and spiral arms with the Square Kilometer Array
Abstract
Very Long Baseline Interferometry (VLBI) at radio wavelengths can provide astrometry accurate to 10 micro-arcseconds or better (i.e. better than the target GAIA accuracy) without being limited by dust obscuration. This means that unlike GAIA, VLBI can be applied to star-forming regions independently of their internal and line-of-sight extinction. Low-mass young stellar objects (particularly T Tauri stars) are often non-thermal compact radio emitters, ideal for astrometric VLBI radio continuum experiments. Existing observations for nearby regions (e.g. Taurus, Ophiuchus, or Orion) demonstrate that VLBI astrometry of such active T Tauri stars enables the reconstruction of both the regions' 3D structure (through parallax measurements) and their internal kinematics (through proper motions, combined with radial velocities). The extraordinary sensitivity of the SKA telescope will enable similar "tomographic mappings" to be extended to regions located several kpc from Earth, in particular to nearby spiral arm segments. This will have important implications for Galactic science, galactic dynamics and spiral structure theories.
Keywords
Cite
@article{arxiv.1412.6481,
title = {Tomography of Galactic star-forming regions and spiral arms with the Square Kilometer Array},
author = {Laurent Loinard and Mark Thompson and Melvin Hoare and Huib Jan van Langevelde and Simon Ellingsen and Andreas Brunthaler and Jan Forbrich and Kazi L. J. Rygl and Luis F. Rodriguez and Amy J. Mioduszewski and Rosa M. Torres-Lopez and Sergio A. Dzib and Gisela N. Ortiz-Leon and Tyler L. Bourke and James A. Green},
journal= {arXiv preprint arXiv:1412.6481},
year = {2014}
}
Comments
To appear in the Proceedings Advancing Astrophysics with the SKA (AASKA14)