David Martinez-Delgado (ARI-University of Heidelberg)

Stellar tidal streams in the halos of nearby spiral galaxies
When Feb 18, 2016 from 02:30 PM to 03:30 PM
  • Colloquium
Where SH Lecture Hall
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Within the hierarchical framework for galaxy formation, merging and tidal interactions are expected to shape large galaxies up to the present day. While major mergers are quite rare at present, minor mergers and satellite disruptions - that result in giant stellar streams - should be common, and are indeed seen in the halos of the Milky Way and the Andromeda galaxy. In the last years,the Stellar Tidal Stream Survey (PI. Martinez-Delgado) has obtained ultra-deep, wide-field imaging of some nearby Milky Way-like  galaxies, based on data taken with a network of small robotic telescopes (0.1-0.5-meter). These images have revealed for first time external views of such stellar tidal streams at unprecedented sensitivity and detail, and provide an opportunity to estimate the frequency, morphology and stellar mass distribution of these structures in the local universe.

In this talk, I will present the latest results our systematic survey of stellar streams, and from N-body modeling of the most striking tidal features. I will also discuss what we can learn from the comparison of our observations with the predictions from L-CDM cosmological simulations of stellar halos, that is the ultimate objective of this project.