eSSENCE research in focus

The Milky Way

Using eScience to map the Milky Way

A key goal of contemporary astrophysics is to discover the history of our Milky Way galaxy: when and where did its stars form, and how did they come to be where they are today? One of the efforts to answer these important question comes from the Gaia satellite, funded by the European Space Agency, which is measuring the distances to around a billion stars.

To complete the data from Gaia we also need the stars’ radial velocities – their speeds measured along the line of sight – and their chemical compositions. Both can be derived from absorption lines that are visible when the light from a star is split up into its different wavelengths: the star’s spectrum.

A collaboration between groups at Lund and Uppsala universities are producing a pipeline to analyse the spectra of around 10000 stars that will be observed each night by 4MOST, an instrument being built for the VISTA telescope at the European Southern Observatory (ESO). This is a much greater data rate than any previous spectrograph, and so new analysis tools need to be developed.

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