Welcome at my Website

I am doing my postdoc in astronomy at the
National Taiwan Normal University
(department of earth sciences) since May 2011.

We plan to use ALMA to investigate certain aspects of evolved stars / asymptotic giant branch (AGB) stars. These observations will try to e.g. answer the questions where intrinsic asymmetries originate, how the dust formation sequence depends on the evolutionary stage and how the wind is initiated in evolved stars. This is done in close collaboration with ASIAA and other institutes.

In my PhD thesis, which I did at the Landessternwarte / State Observatory Heidelberg, I was mainly involved in interferometric observations of extra- solar planet host stars and AGB stars.

I started my first year working on the PRIMA project, which will use astrometric measurements to find extrasolar planets. This VLT interferometer will be available in 2011/12 and is under commissioning right now. I did simulations related to the data reduction, and preparatory work for the related science program ESPRI.

With beginning of my second year I started working on the reduction and interpretation of AGB star data received with MIDI. These observations allowed us to fit for stellar diameters and to study the structure of the dense circumstellar environment. We were particular interested on the location of the molecular and dust formation layers and its dependence on pulsation cycle, mass loss rate, and chemistry.

In addition of reducing the data, I modeled the visibilities, investigated the light curves and modeled the star+dust configuration with a radiative transfer code. It is also planned to apply dynamic model atmospheres to that data.

NTT (La Silla, Chile) @sunset (March 2008, HDR picture)

last update: 5th May, 2011 (optimized for Firefox 4)

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Ronny Zhao-Geisler © 2011 all rights reserved