Final Activity Report Summary - SPNWE (Ages of Galaxies and Constraints on Galaxy Formation)
The aim of the project was to develop a modelling of astronomical data that could ensure precision in the derivation of the ages of distant galaxies. The age of a galaxy is an extremely important property that can set constraints to galaxy formation models, that in turn are strictly connected to our modern view of evolution in the Universe in a cosmological context.
The age of a distant galaxy is obtained by the age of its stars, which in turn is obtained by comparing the luminous emission by the stars themselves with so-called stellar population models. These models exploit robust knowledge of the physics of the stellar interiors to make predictions of the energy emitted by an ensemble of stars such as a galaxy. The fellow is a well-recognised expert of such models and together with her collaborators has contributed substantially to the improvement in the field. In particular, in 2005 while at Oxford she has published a paper describing innovative models that for the first time incorporate the energy contribution by red giant stars evolving through the last giant phase of stellar evolution.
The inclusion of these stars has dramatically improved the interpretation of galaxy data, noticeably of the primeval galaxies populating the extreme Universe whose data can be acquired only with modern satellites. Previous models failed to describe the energetic emission of these galaxies and could not provide reliable estimates of the galaxy formation epochs and masses. The original modelling by the fellow in 2005 has definitively opened a new era in this type of study. In 2007, the major competitors of the fellow have publicly agreed that the new models are superior.
The age of a distant galaxy is obtained by the age of its stars, which in turn is obtained by comparing the luminous emission by the stars themselves with so-called stellar population models. These models exploit robust knowledge of the physics of the stellar interiors to make predictions of the energy emitted by an ensemble of stars such as a galaxy. The fellow is a well-recognised expert of such models and together with her collaborators has contributed substantially to the improvement in the field. In particular, in 2005 while at Oxford she has published a paper describing innovative models that for the first time incorporate the energy contribution by red giant stars evolving through the last giant phase of stellar evolution.
The inclusion of these stars has dramatically improved the interpretation of galaxy data, noticeably of the primeval galaxies populating the extreme Universe whose data can be acquired only with modern satellites. Previous models failed to describe the energetic emission of these galaxies and could not provide reliable estimates of the galaxy formation epochs and masses. The original modelling by the fellow in 2005 has definitively opened a new era in this type of study. In 2007, the major competitors of the fellow have publicly agreed that the new models are superior.