Galactic-Field IMFs of Massive Stars
نویسندگان
چکیده
Over the past years observations of young and populous star clusters have shown that the stellar IMF appears to be an invariant featureless Salpeter power-law with an exponent α = 2.35 for stars more massive than a few M⊙. A consensus has also emerged that most, if not all, stars form in stellar groups and star clusters, and that the mass function of young star clusters in the solar-neighborhood and in interacting galaxies can be described, over the mass range of a few 10M⊙ to 10 M⊙, as a power-law with an exponent β ≈ 2. These two results imply that galactic-field IMFs for early-type stars cannot, under any circumstances, be a Salpeter power-law, but that they must have a steeper exponent αfield>∼ 2.8. This has important consequences for the distribution of stellar remnants and for the chemo-dynamical and photometric evolution of galaxies. Subject headings: stars: formation – stars: luminosity function, mass function – galaxies: star clusters – galaxies: evolution – galaxies: stellar content – Galaxy: stellar content
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