Uncloaking globular clusters of the inner Galaxy Javier Alonso-García Department of Astronomy University of Michigan In collaboration with: Mario Mateo (Department of Astronomy, UMich) Bodhissatva Sen (Department of Statistics, UMich) Moulinath Banerjee (Department of Statistics, UMich) Michael Woodroofe (Department of Statistics, UMich)

Galactic spheroids contain a large fraction of the stellar mass in the local universe. (Zoccali et al. 2003, Fukugita et al. 1998) Understanding of their formation and evolution is crucial to comprehend galaxy formation and to reconstruct the whole cosmic star formation history.

But it is only in a few cases that we can resolve the stellar populations. M32 M31 bulge MW bulge

The inner MW globular clusters characteristics provide powerful constraints on models of the formation and evolution of the bulge of the Milky Way. NGC 6304 NGC 6624

Serious limitation in the study of many GCs: the existence of large and differential extinction by foreground dust.

Our Project 25 inner Galaxy GCs Imacs on Magellan B,V and I observations FOV 15.4’x15.4’ New dereddening technique Goal: to determine the relative mixtures, age sequence, and chemical properties of the cluster populations in the inner Milky Way.

Dereddening Technique Obtaining a ridgeline. Moving the stars along the reddening vector. Smoothing the shifts. Iterative process.

M62 Before After

M19 Before After

M19

An important by-product of this process is a map of the differential extinction across a cluster

GC-Field separation Observation Besançon Model