Probing the IMF Beyond the Milky Way: Integrated Spectra of Young Super-Star Clusters in Nearby Galaxies
Abstract
Understanding the origin of the Initial Mass Function (IMF) remains one of the most challenging problems in astronomy. Discerning what physical parameters control its shape will help us understand the process of star formation and allow us to draw conclusions about mass-to-light ratios in other galaxies. Studies probing the IMF in young clusters within 1 kpc suggest that it does not vary greatly with local conditions (Meyer et al. 2000). Thus IMF measurements in more extreme regions of star formation than those accessible in the Milky Way are needed to investigate the dependence of the IMF on initial conditions.
We present results of an ongoing spectroscopic survey of young super-star clusters in nearby galaxies representing a range of formation environments, with the goal of constraining their IMF. Low-mass pre-main sequence stars, orders of magnitude brighter than their main sequence counterparts, produce observable late-type absorption features in the integrated near-IR spectra of these clusters (Meyer & Greissl 2005). Using this technique, we report the direct detection of low mass stars in a super-star cluster for the first time. We further report constraints on the IMF for our cluster sample through analysis of absorption features tracing the ratio of high- to low- mass stars.- Publication:
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American Astronomical Society Meeting Abstracts #213
- Pub Date:
- January 2009
- Bibcode:
- 2009AAS...21334907G