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arXiv · 1101.4900

The Role of the IGIMF in the chemical evolution of the solar neighbourhood

Francesco Calura·Simone Recchi·Francesca Matteucci·Pavel Kroupa
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Abstract

The integrated galactic initial mass function (IGIMF) is computed from the combination of the stellar initial mass function (IMF) and the embedded cluster mass function, described by a power law with index beta. The result of the combination is a time-varying IMF which depends on the star formation rate. We applied the IGIMF formalism to a chemical evolution model for the solar neighbourhood and compared the results obtained by assuming three possible values for beta with the ones obtained by means of a standard, well-tested, constant IMF. In general, a lower absolute value of beta implies a flatter IGIMF, hence a larger number of massive stars, higher Type Ia and II supernova rates, higher mass ejection rates and higher [alpha/Fe] values at a given metallicity. Our suggested fiducial value for beta is 2, since with this value we can account for most of the local observables. We discuss our results in a broader perspective, with some implications regarding the possible universality of the IMF and the importance of the star formation threshold.

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Francesco Calura, Simone Recchi, Francesca Matteucci, Pavel Kroupa. 2011-01-25. The Role of the IGIMF in the chemical evolution of the solar neighbourhood. https://arxiv.org/abs/1101.4900

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