1. Exploding stars And the modeling of Dwarf galaxies http://www.spacetoday.org/images/DeepSpace/Stars/StarWR124Hubble.jpg

2. Dwarf Galaxies  What are they?  Where are they?  Why are we interested in them?

3. Dwarf galaxy http://upload.wikimedia.org/wikipedia/en/a/a7/Phoenix_Dwarf.jpg Ultra Faint DG

4. Dwarf Galaxies  What are they?  Where are they?  Why are we interested in them?

5. http://www.sciencecentric.com/images/news/map_milky_way_1000_1000.jpg

6. Dwarf Galaxies  What are they?  Where are they?  Why are we interested in them?

7. Ultra Faint DG’s Very recent discovery ~2005 Low luminosity and metallicity Extreme dark:baryonic matter ratio Remnants of early structures in galaxy formation Closely linked to the first stars (pop III) Chemical Tagging provides valuable information about the nature of these galaxies Black dots: Milky Way stars Blue squares: DG stars Red stars: Ultra faint DG stars

8. Modeling Supernova SN 1987A: NASA, ESA, P. Challis and R. Kirshner (Harvard-Smithsonian Center for Astrophysics)

9. Calculating mean yields Using data from: papers by Nomoto et al, Woosley et al and Chieffi et al. Using sum of all isotopes for each element Mean yields where calculated using numerical integration of: Linear interpolation of (yield of a particular element) α M Salpeter Initial Mass Function

12. SN Subroutine Part of a larger model of Dwarf Galaxy evolution Fortran subroutine to calculate yields of a certain element for a specified mass and metallicity, based on Nomoto SN/HN yields Using bilinear interpolation on the tabulated values

14. Conclusions The stellar models are sensitive to a range of variables Small changes in explosion energy and metallicity influence yields Abundances of odd elements are particularly influenced by the metallicity of a star a metallicity parameter and a HN/SN flag has been incorporated into a new stellar yield subroutine which will form part of a model of galactic chemical evolution

15. Acknowledgements and Refernces Special thank you: Dr. Torgny Karlsson, for the time he spent helping me learn some new physics. Also thanks to Dick Hunstead for organizing the projects. References: Nucleosynthesis Yields of Core-Collapse Supernovae and Hypernovae, and Galactic Chemical Evolution Ken’ichi Nomoto, Nozomu Tominaga, Hideyuki Umeda, Chiaki Kobayashi, Keiichi Maeda, Nuclear Physics A (2006) NUCLEOSYNTHESIS AND EVOLUTION OF MASSIVE METAL-FREE STARS Alexander Heger, S. E. Woosley ApJ, March 21, 2008 SN 1987A: NASA, ESA, P. Challis and R. Kirshner (Harvard-Smithsonian Center for Astrophysics) http://www.sciencecentric.com/images/news/map_milky_way_1000_1000.jpg http://www.spacetoday.org/images/DeepSpace/Stars/StarWR124Hubble.jpg

16. Mixing Effects Mixing effects for B=1.2 Yield

17. Current Supernova Models Simulations are missing ~10 51 ergs! (erg=1 × 10−7 joules) To compensate for this missing energy: – thermal explosion – piston – enhanced neutrino opacity Mixing in the star

20. Data sets Mean Yields Subroutine Galactic Model Whole bunch of reading

21. Ultra Faint DG’s Very recent discovery ~2005 Low luminosity and metallicity Extreme dark:baryonic matter ratio Closely linked to the first stars (pop III) Remnants of early structures in galaxy formation Chemical Tagging provides valuable information about the nature of these galaxies Black dots: Milky Way stars Blue squares: DG stars Red squares: Ultra faint DG stars