1. 14-The Evolution of Stars and Gas in Galaxies

2. Elliptical Galaxies

3. Spiral Galaxies

4. Barred Spiral Lenticular Irregular (Large Magellanic Cloud) Dwarf Spheroidal Galaxy

7. Isochrone - 2.5x10 8 yrs Isochrone - 4x10 9 yrs

13. IMF in the ρ Oph Association

15. Ivan Baldry (2008) www.astro.ljmu.ac.uk/~ikb/research/imf-use-in-cosmology.html

16. “The observations are consistent with a single underlying IMF, although the scatter at and below the stellar/sub-stellar boundary clearly calls for further study.” Bastian et al, 2010, ARAA, 48, 339

17. Is the IMF Universal in Space and Time? The situation is complicated! Doesn ’ t seem to be tremendously different within the Milky Way Galaxy, although some obvious differences exist M/L in other galaxies - tricky - L is dominated by late-type giants, while M is dominated by dwarf stars and dark matter However, the presence of metals in high-z systems might require a flatter IMF with more massive stars than local IMF

18. What about the Star-Formation Rate? Stars more massive than 2 M sun evolve so quickly they are a good indicator of current SFR. The past SFR needs to include lower-mass stars - much harder to do (don ’ t know ages!) Oort Limit (kinematic) - stars are 70-95 M sun pc -2. Guessing the time dependence gives 1.5 < SFR < 25 M sun pc -2 Gyr -1 (but we don ’ t really know if SFR is currently decreasing or increasing!) Star counts give 43-144 M sun pc -2 and 3 < SFR < 7 M sun pc -2 Gyr -1 Rough mean of these 2 methods: SFR ~ 10 (+10/-5) M sun pc -2 Gyr -1

19. The SFR Depends on Location in the MWG! Current MWG star formation is dominated by 2 regions: 1.Innermost 1 kpc 2.Ring between 5-8 kpc of center And the actual rate is probably dominated by a wide variety of (often) little understood processes: gas density, shock conditions (local sound speed, shock frequency & strength), global and local gas rotation and shear, magnetic field strength, gas metal abundance (cooling!) and the background star density. May need to depend on more general ideas based on relevant factors - a complete analytic description is probably beyond hope at this point.

20. Nucleosynthesis & Chemical Enrichment Main Sequence M<1.1M sun - pp chain makes He from H M>1.1M sun - CNO makes He from H, while N builds up at expense of CO (Note that this requires pre-existing C) Post-MS Low-mass stars: Red Giant Tip through Horizontal Branch to Asymptotic Giant Branch - He converted to C and O - winds & PN High-mass stars: He converted to C and O heavy metals produced through Fe - winds & SN II Some WD stars in binaries also return heavies - SN I

23. “ G-Dwarf Problem ” (There is a deficit of metal poor G stars) Solar neighborhood can be modeled as a closed system It started as 100% metal- free gas The IMF is constant The gas is chemically homogeneous with time Infall - most stars formed after significant enrichment Pregalactic burst of massive stars Variable IMF ISM chemically inhomogeneous

27. Clouds Above the Galactic Plane Galactic Fountains? Primordial Local Group Mini-Clouds Tail-End of MWG Formation Tidally-Stripped Gas from Passing Small Galaxy

28. Magellanic Stream

31. Abundance Gradients in the Galaxy??

32. Korotin et al. 2014, arXiv:1408.6103v1

33. Rosolowsky & Simon (2007)