Dynamic atmospheres of cool giants and MATISSE

Supervisor: Josef Hron

Contact information: josef.hron@univie.ac.at

Co-supervisors: Claudia Paladini (ESO, Chile), Susanne Höfner (Uppsala)

Expected duration: 9 months

Project description & Goals:

MATISSE at the VLT Interferometer provides for the first time interferometric data in the full thermal  infrared (L,M and N). One of the prominent science cases are the dynamic atmospheres of cool giants as the wavelengths covered by MATISSE allow simultaneous observations of molecules and dust. This yields unique constraints for the physical processes going on and for the time-dependent model atmospheres.

Obtaining these constraints requires a comparison of the interferometric observables with predicted synthetic observables from a grid of models using the proper wavelength range, spectral resolution, spatial frequencies and stellar parameters. The goal of this master project is to develop a Python toolbox to calculate the synthetic observables and compare them with observations. This should then be applied to representative cases.

Working plan & Milestones (including final thesis):

• Month 1: familiarize with the output of dynamic models and interferometric observables
• Months 2-6: develop and test the code
• Months 7-8: application to representative cases
• Months 9: writing the thesis

Requirements / special skills: good knowledge of Python, basic kowledge of and interest in interferometry and stellar atmospheres

References:

Paladini+ Interferometric properties of pulsating C-rich AGB stars. Intensity profiles and uniform disc diameters of dynamic model atmospheres,  Astronomy and Astrophysics, Volume 501, Issue 3, 2009, pp.1073-1085

Rau+ The adventure of carbon stars. Observations and modeling of a set of C-rich AGB stars,  Astronomy & Astrophysics, Volume 600, id.A92, 2017, 21 pp.