1. Revealing Elliptical Galaxy Halos Duncan Forbes, Swinburne University

2. Collaborators Robert Proctor (Sao Paulo) Alan Brito (Swinburne) George Hau (Swinburne) Lee Spitler (Swinburne) Caroline Foster (Swinburne) Christina Blom (Swinburne) Jean Brodie (UCSC) Aaron Romanowsky (UCSC) Jacob Arnold (UCSC) Jay Strader (Harvard) Soeren Larsen (Utrecht)

3. Why study elliptical galaxy halos? Also some kinematic signatures of galaxy formation only apparent at large radii

4. Halo stellar populations and kinematics using Deimos on Keck multiplexing times 4 ! MetallicityKinematics Globular Clusters~10 R eff Foster et al. In prep ~10 R eff Romanowsky et al. 2009 Halo starlight~3 R eff Foster et al. 2009 ~3 R eff Proctor et al. 2009 “Need outer halo kinematics” - Rix

5. Deimos spectra and fits to the galaxy halo light in the 3 Calcium Triplet regions S/N

6. NGC 2768: Deimos as an IFU

7. Velocity map for NGC 2768 Sauron maps R eff = 64 arcsec

8. Radial Kinematics - NGC 821 Proctor,Forbes etal. 2009 NGC 821: a low DM galaxy?

9. N2768 and N821

10. Anisotropy (Binney) diagram NGC 2768 Fast -> Faster NGC 821 Fast -> Slow

11. Metallicity gradients (<1R e ) vs mass Spolaor et al. 2009 Log sigmaMBMB

12. NGC 2768: Metallicity to ~3 R e

13. Galaxy Halo Mass Globular Cluster System Mass New Halo vs Globular Cluster Mass (linear) Relation Spitler & Forbes 2008

14. Globular Cluster Formation GC formation is directly proportional to the host halo mass with little environmental trend 0.007% of Halo Mass = (Globular Cluster System Mass)

15. Science progresses best when observations force us to alter our preconceptions. Vera Rubin Teacher and Coauthor

16. Conclusions New method for measuring 2D halo starlight kinematics and stellar populations to large R e Fast/slow rotators may change with radius. Outer gE halos may be very metal-poor, built by low mass progenitors? Mass modelling – see talk by Romanowsky. New method for obtaining halo masses (based on globular cluster system mass) – see poster by Spitler.