Bibcode
Weidner, C.; Vazdekis, A.; Pflamm-Altenburg, J.; Kroupa, P.
Bibliographical reference
Monthly Notices of the Royal Astronomical Society, Volume 436, Issue 4, p.3309-3320
Advertised on:
12
2013
Citations
86
Refereed citations
78
Description
Observational studies are showing that the galaxy-wide stellar initial
mass function (IMF) is top-heavy in galaxies with high star formation
rates (SFRs). Calculating the integrated galactic stellar initial mass
function (IGIMF) as a function of the SFR of a galaxy, it follows that
galaxies which have or which formed with SFRs >10 M⊙
yr-1 would have a top-heavy IGIMF in excellent consistency
with the observations. Consequently and in agreement with observations,
elliptical galaxies would have higher mass-to-light ratios as a result
of the overabundance of stellar remnants compared to a stellar
population that formed with an invariant canonical stellar IMF. For the
Milky Way, the IGIMF yields very good agreement with the disc- and the
bulge IMF determinations. Our conclusions are that purely stochastic
descriptions of star formation on the scales of a parsec and above are
falsified. Instead, star formation follows the laws, stated here as
axioms, which define the IGIMF theory. We also find evidence that the
power-law index β of the embedded cluster mass function decreases
with increasing SFR. We propose further tests of the IGIMF theory
through counting massive stars in dwarf galaxies.
Related projects
Traces of Galaxy Formation: Stellar populations, Dynamics and Morphology
We are a large, diverse, and very active research group aiming to provide a comprehensive picture for the formation of galaxies in the Universe. Rooted in detailed stellar population analysis, we are constantly exploring and developing new tools and ideas to understand how galaxies came to be what we now observe.
Ignacio
Martín Navarro