ASTRONOMY COLLOQUIUM<br>3D Spectroscopy of Giant H II Regions in Nearby Spiral Galaxies</br>

Integral field spectroscopy (IFS) allows us to simultaneously record spectral and spatial information over the observed area. Taking advantage of this capability, a program was started to search for possible variations of physical parameters inside star-forming regions. The ideal candidates are H II regions in face-on nearby spiral galaxies, allowing also to study the differences in the star formation process in the center vs. the outer disk environments. In this talk I will present IFS observations of H II regions in M33 and M101. Their physical properties (density, temperatures, ionic and total abundances, etc.) were derived at different scales, from individual spatial resolution elements (spaxels) to the whole integrated field. Multi-scale results and comparison with literature show the limitation of the methodologies developed for global observations (long slit, single aperture) when used with spatially resolved data. In this case the ionization structure within the nebula must be taken into account and a different interpretation of the results is required. BPT diagnostic diagrams were used to characterize the contribution of different parts of the nebula to the global result, also to test photoionization models with a simple approach to include spatial information.

Colloquia are generally preceded by tea and cookies at 3:30 in the Owl room (Dennison 845). For more information, please contact astro.colloquia@umich.edu.

Astronomy Colloquia listings for Winter 2014.