Evidence for IMF Variations from the Integrated Light of SDSS Galaxies - Astrophysics > Cosmology and Nongalactic AstrophysicsReport as inadecuate




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Abstract: The H alpha equivalent width EW is the ratio of the H alpha flux to thecontinuum at 6565{\AA}. In normal star forming galaxies the H alpha flux isdominated by reprocessed photons from stars with masses greater than 10 M o andthe 6565{\AA} continuum is predominantly due to 0.7-3.0 M o red giant stars. Inthese galaxies the H alpha EW is effectively the ratio of high mass to low massstars and is thus sensitive to the stellar initial mass function IMF. InHoversten and Glazebrook 2008 we used ~131,000 galaxies from the Sloan DigitalSky Survey to show evidence for systematic variations in the IMF with galaxyluminosity. In this proceeding we use that sample, with the addition of Hdelta A measurements, to investigate other parameterizations of the IMF. Wefind evidence for IMF variations with surface brightness, and also show that,modulo uncertainties in spectral synthesis models, that 120 M o stars areimportant in accounting for the observed H alpha EW distribution.



Author: Erik A. Hoversten, Karl Glazebrook

Source: https://arxiv.org/







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