Mid-infrared observations of embedded super star clusters at high spatial resolution
Abstract
Observations of mid-IR fine-structure lines in external galaxies are widely used as diagnostics of starformation providing e.g. constraints on the IMF, starburst age etc. However as these observations are taken through large apertures (e.g. ISO, even SPITZER and in the near future Herschel) the line measurements are likely to consist of contributions from super star clusters (SSCs), the diffuse ISM and other sources rendering their interpretation in the above terms difficult. In addition, photoionization models are strongly underconstrained in such conditions given the lack of observable constraints e.g. on the size, geometry etc. of the emission regions. To determine reliable constraints on the upper part of the IMF we have undertaken high spatial resolution mid-IR imaging and spectroscopy of young starburst galaxies with TIMMI2 on the ESO 3.6 m. Results on the prototypical starburst NGC 5253 are presented here using detailed photoionization models to reproduce a large number of observables including mid-IR to radio observations at various spatial resolutions. In particular we show that results based on large aperture observations cannot yield accurate constraints on quantities such as the upper mass cut-off and age.
- Publication:
-
SF2A-2004: Semaine de l'Astrophysique Francaise
- Pub Date:
- December 2004
- Bibcode:
- 2004sf2a.conf..639M