CGUC Seminário - Do we live in a spiral galaxy? - 22 de junho de 2012



Do we live in a spiral galaxy?

Manuel Silva

(Centre for Astrophysics Research - Univ. of Hertfordshire)



A direct observation of the spiral structure of the Galaxy is hindered by our position in the middle of the Galactic plane.
We propose a method based on the analysis of the birthplaces of high galactic latitude runaway stars to map the spiral arms and determine their dynamics. As a proof of concept, the method is applied to a local sample of early-type stars and a sample of runaways stars to obtain estimates of the pattern speed ( Omega_{p,local}=20.6+-0.5km/s and Omega_{p,runaway}=21.2+-7.7km/s ) and \phi_{runaway}=-57.2◦+-16.9◦.
We also estimate the performance of this method once the data gathered by Gaia, in particular for runaway stars observed on the other side of the Galaxy, is available.



22 de junho de 2012 | 11:00



Auditório do Observatório Astronómico da Universidade de Coimbra, Portugal