Talk by Camilla Juul Hansen – University of Copenhagen

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Talk by Camilla Juul Hansen

Camilla Juul Hansen will give this week's cake talk Thursday 21 March 2013 at 14:15 in the DARK lounge.

Camilla is a postdoc at Heidelberg University, ZAH. Her main research areas are spectroscopy and abundance analysis of cool stars.

Title: Silver, Palladium and the weak r-process

Abstract: A spectral analysis can provide key information about the fundamental
stellar parameters, the stellar age, as well as trace the long gone
massive object that created the elements  we study in the 'living' low
mass successor. By studying abundances in large stellar samples with stars
of varying age and metallicity, we hope to understand the chemical
evolution of our Galaxy; how and when formation processes came into play,
and how they created the abundances we can derive from observations. The
heavy elements (Z>37) have posed many problems, and to date we still do
not know exactly how and where they form. The majority of these heavy
elements are created in very energetic environments by capturing neutrons
onto seed nuclei. The neutron-capture processes split into two main
categories depending on the speed of the neutron captures compared to the
decay of the radioactive nuclei, namely a slow and a rapid neutron-capture
process (s- and r-process, respectively). Studies of asymptotic giant
branch stars as well as massive stars have revealed that the s-process
branches into two components - a main and a weak. Similar speculations
have been made for the r-process. Here I will show you strong
observational indications from silver and palladium abundances for the
existence of a second, weak r-process.