Fredagskollokvium: UV chemistry in the circumstellar envelopes around evolved stars

Maryam Saberi, Rosseland Centre for Solar Physics, Institute of Theoretical Astrophysics, University of Oslo

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Dr. Maryam Saberi Postdoctoral Fellow at Rosseland Centre for Solar Physics, University of Oslo. Photo: M. Saberi

Low- and intermediate-mass stars (M < 8M) eject a substantial amount of their material (up to 80%) into space during a late phase of stellar evolution, the asymptotic giant branch (AGB) phase. 
Consequently, AGB stars are major players in the cosmic gas and dust cycle. An extended circumstellar envelope (CSE) will be created around the star as a consequence of the intense mass loss. Observations of molecular species and dust content in CSEs help us to broaden our knowledge on mass-loss processes, stellar properties, and the CSE chemistry. In this presentation, I will give an introduction to the CSE chemistry with a focus on the UV chemistry. Then, I will show how high spectral and spatial resolution ALMA observations can help us to quantify the impact of various sources of UV radiation in the CSE chemistry around evolved stars.
Bildet kan inneholde: svart, verdensrommet, astronomisk objekt, blå, stemning.
Ultraviolet mosaic of Mira's bow shock and tail obtained using NASA's Galaxy Evolution Explorer (GALEX) NASA. Image credits: Bob Paz; NASA/JPL-Caltech/C. Martin (Caltech)/M. Seibert (OCIW).

Join the Zoom Colloquium from 11 AM.

Publisert 16. jan. 2020 19:49 - Sist endret 29. mai 2020 10:53