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Thursday, 13 April 2023 |
Video-Recording for any system with MP4-support - Video.mp4 (ca. 368 Mb) |
15:15 – 16:15
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"Observability of
short-period rocky exoplanets"
Yamila Miguel
(Leiden Observatory)
Abstract: Short-period rocky exoplanets
can reach surface temperatures
high enough to melt their silicate crust.
Theory predicts that the
resulting lava oceans outgas their
volatile components, attaining
equilibrium with the overlying vapour.
This could create atmospheres
made out of silicates that mix with other
volatiles that might have been
present in such atmospheres. With the
recently successful deployment of
the James Webb Space Telescope (JWST), it
is now possible to characterise
these worlds.
In this talk, we assess JWST observability
of key spectral features
by self-consistently modelling these
atmospheres. We use outgassed
equilibrium chemistry and radiative
transfer methods to compute
temperature-pressure profiles, atmospheric
chemical compositions
and emission spectra. Our results indicate
that SiO and SiO2 infrared
features are the best in pure lava worlds.
However, even a small amount
of volatiles, especially H2O and H–, may
hinder its observability. We
also find that the carbon to oxygen (C/O)
ratio plays a large role in
determining the abundance of SiO.
Detecting SiO on a strongly irradiated
planet could indicate an atmosphere with
high metallicity and a low
C/O ratio, which may be a result of
efficient interaction between the
atmosphere and the underlying melt.
Biography: Yamila Miguel got her PhD in
2011 in Astronomy from the
Universidad Nacional
de La Plata in Argentina. She then had a postdoctoral
fellowship at the Max Planck Institute for
Astronomy in Heidelberg
and in 2015 the Henri Poincare
postdoctoral fellowship at the Côte
d’Azur Observatory. After another
fellowship by the National Centre
for Space Studies, also in Nice, she
became an Assistant Professor at
Leiden Observatory.
Yamila Miguel is well known for her public
outreach activities through
lectures, newspaper articles, and radio
appearences. She is a member of
the Young Academy Leiden.