Letters of Intent received in 2016
LoI 2018-1963
Stars on the run - The Gaia perspective
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Date:
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20 August 2018 to 31 August 2018 |
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Category:
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GA Focus meeting
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Location:
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Vienna, Austria
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Contact:
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Stephan Geier (geier@astro.uni-tuebingen.de) |
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Coordinating division:
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Division G Stars and Stellar Physics |
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Other divisions:
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Division G Stars and Stellar Physics
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Co-Chairs of SOC:
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Warren Brown (CfA, Harvard) |
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Co-Chairs of LOC:
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Topics
Surveys for run-away and hypervelocity stars
Dynamics of stellar clusters and the Galactic centre
Chemical composition of run-away and hypervelocity stars
Core-collapse and thermonuclear supernova ejection
High velocity neutron stars
Bow shocks from run-away stars
Binary stellar evolution models and population synthesis
Satellite Galaxy and extragalactic origin
Rationale
Letter of Intent
Run-away stars are produced by dynamical interaction in various environments. Several processes have been suggested for their origin, which include ejection from star clusters and the Galactic Centre, in binary supernova explosions, and from satellite galaxies. Galactic center ejections are linked to the nature and environment of the central massive black hole; the trajectories of these stars -- which travel from the very center to the outer halo -- are potentially unique probes of the Galaxy's dark matter distribution. The fastest run-away stars known, the hyper-velocity stars, travel so fast that they are unbound from the Galaxy. The list of known run-aways includes early type main sequence stars in the Galactic halo as well as neutron stars.
In 2016 observers and theoreticians working on the diverse fields relevant to understand run-away and hyper-velocity stars gathered for the first time for a very successful workshop held in Bamberg, Germany (http://www.sternwarte.uni-erlangen.de/hvs2016).
One of the main conclusions of this meeting was that high-precision astrometry is a prerequisite for tracing the place of origin of these stars, whether that is a particular cluster, the centre of the Galaxy, or elsewhere, and to put constraints on the various acceleration scenarios proposed.
In 2017 the Gaia mission Data Release 2 will provide astrometry of unprecedented accuracy for most of the run-away and hypervelocity stars known, and allow us to discover and study much larger samples. The aim of this two-day focus meeting is to confront theoretical predictions with the first results based on Gaia data.