1 / 19

Aaron Dotter (STScI) HotSci 20 July 2011

The Galactic Globular Cluster Age-Metallicity Relation and the Formation of the Galaxy. Aaron Dotter (STScI) HotSci 20 July 2011. Based on “ Globular clusters in the outer Galactic halo: new HST/ACS imaging of 6 globular clusters and the Galactic globular cluster age-metallicity relation ”

ellery
Télécharger la présentation

Aaron Dotter (STScI) HotSci 20 July 2011

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. The Galactic Globular Cluster Age-Metallicity Relation and the Formation of the Galaxy Aaron Dotter (STScI) HotSci 20 July 2011

  2. Based on “Globular clusters in the outer Galactic halo: new HST/ACS imaging of 6 globular clusters and the Galactic globular cluster age-metallicity relation” A. Dotter, A. Sarajedini, & J. Anderson ApJ in press—arxiv:1106.4307

  3. INTRODUCTION Globular cluster ages and metallicities provide important insight into their host galaxy's chemical evolution—even if that galaxy is no more. Milky Way GCs Harris (2010) Inside/Outside Solar Circle: 2/1

  4. Omega N6397 47T ω Cen NGC 6397 47 Tuc Very Blue HB B/(B+R)=[N/A] ∆(V-I)=0.97 Blue HB B/(B+R)=0.96 ∆(V-I)=0.94 Red HB B/(B+R)=0 ∆(V-I)=0.15 Jay Anderson

  5. The 2nd Parameter & Halo Formation RGC < 5 8 < RGC < 12 Metallicity→ 5 < RGC < 8 RGC > 12 Searle & Zinn (1978) Red→ HB Morphology → Blue

  6. The HST Era HST/WFPC2 covered RGC > 50 kpc (5 GCs) HST/ACS covers > 70 GCs: RGC < 20 kpc well covered by the HST/ACS Survey of Galactic GCs RGC = 30-50 kpc and 15-20 kpc complete with Cycle 17 follow-up RGC = 20-30 kpc not done! HST/WFC3: none yet, several underway . . .

  7. Age and HB Morphology ? RGC < 5 8 < RGC < 12 Metallicity→ 5 < RGC < 8 RGC > 12 Searle & Zinn (1978) Red→ HB Morphology → Blue Age (Gyr)

  8. Age and HB Morphology Intrinsic Properties Metal-rich ⇒ Red HB Intermediate ⇒ ? Metal-poor ⇒ Blue HB ~70 GCs Δ(V-I)

  9. Age and HB Morphology Δ(V-I)

  10. Age and HB Morphology Δ(V-I)

  11. Age and HB Morphology Δ(V-I)

  12. Age and HB Morphology Δ(V-I)

  13. Age and HB Morphology Δ(V-I)

  14. Age and HB Morphology Δ(V-I)

  15. The 2nd Parameter, Explained

  16. Dwarf Galaxy Chemical Evolution M54+Sagittarius from the HST/ACS Survey of Galactic Globular Clusters (Siegel et al. 2007)

More Related