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| Paper: |
The Role of the Integrated Galactic Initial Mass Function in the Chemical Evolution of the Solar Neighborhood |
| Volume: |
440, UP2010: Have Observations Revealed a Variable Upper End of the Initial Mass Function? |
| Page: |
279 |
| Authors: |
Calura, F.; Recchi, S.; Matteucci, F.; Kroupa, P. |
| 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 β.
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 neighborhood and compared the
results obtained by assuming three possible values for β with the
ones obtained by means of a standard, well-tested, constant IMF.
In
general, a lower absolute value of β implies a flatter IGIMF, hence
a larger number of massive stars,
higher Type Ia and II supernova rates, higher
mass ejection rates
and higher [α/Fe] values at a given metallicity.
Our suggested fiducial value for β 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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