1. Tomography of Galactic star-forming regions and spiral arms with the Square Kilometer Array
- Author
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Loinard, Laurent, Thompson, Mark, Hoare, Melvin, Huib Jan van Langevelde, Ellingsen, Simon, Brunthaler, Andreas, Forbrich, Jan, Rygl, Kazi L. J., Rodriguez, Luis F., Mioduszewski, Amy J., Torres-Lopez, Rosa M., Dzib, Sergio A., Ortiz-Leon, Gisela N., Bourke, Tyler L., and Green, James A.
- Subjects
Astrophysics - Solar and Stellar Astrophysics ,Astrophysics of Galaxies (astro-ph.GA) ,Astrophysics::Instrumentation and Methods for Astrophysics ,FOS: Physical sciences ,Astrophysics::Solar and Stellar Astrophysics ,Astrophysics::Earth and Planetary Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics - Astrophysics of Galaxies ,Solar and Stellar Astrophysics (astro-ph.SR) ,Astrophysics::Galaxy Astrophysics - 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., To appear in the Proceedings Advancing Astrophysics with the SKA (AASKA14)
- Published
- 2014