2022J7ZFRA – Exo-CASH

2022J7ZFRA – Exo-CASH
CUP: C53D23001100006
PI: Giuseppina Micela

 

 

 

 

 

Exo-planetary Cloudy Atmospheres and Stellar High energy (Exo-CASH)

 

The objective of the project is the determination of the role of the high-energy flux of the host star in shaping the properties and evolution of exoplanetary atmospheres. We expect relevant effects on temperature and pressure profiles, on chemical abundances, and on the formation of particulates. In particular, high-energy stellar radiation changes the ionisation level, modifying the chemical reactivity and inducing departure from chemical equilibrium, activating chemical routes otherwise inhibited. Furthermore, it may trigger precursors of hazes and particulates that will significantly impact the atmospheric structure. In fact, hazes and clouds are one of the most important causes affecting the observation of the spectrum of the planetary atmosphere, creating an opaque layer that prevents the observation of the components below.

We will focus on a representative sample of giant exoplanets.

For each of these systems, we plan 1) to determine the stellar high energy flux and its properties, 2) to build a self-consistent model of the atmosphere with a detailed description of the radiation transfer, the secondary electron cascade, the possible formation of hazes and clouds, and the corresponding induced chemistry, and 3) to simulate Ariel observations of the derived synthetic spectrum, using the dedicated simulator developed by the mission consortium, in order to verify the observability of the atmospheres, and the possible detectability of spectral diagnostics of star-planet interaction.

The project is conducted by two research Units (INAF- Osservatorio Astronomico di Palermo, CNR – Istituto per i Processi Chimico-Fisici)

The work is organized on three axes subdivided in sub-tasks

 

Axis A

Axis A.1: Selection and prioritisation of planetary systems to be analysed (resp. G. Micela, Unit 1);

Axis A.2: Determination of the high energy properties of the host stars of the selected systems (resp. A. Maggio, Unit 1);

 

 

Axis B

Axis B.1: Physical and chemical modelling of the atmospheres of the selected planets (resp. C. Cecchi Pestellini, Unit 1);

AxisB.2: Analysis of the particulate formation conditions in the derived conditions, determination of the optical properties of theparticles (resp A. Iati, Unit 2)

 

Axis C

Axis C.1: Ab initio calculation of spectra from atmospheric layers (resp. F. Saija, Unit 2)

Axis C.2: Spectral synthesis of the entire atmosphere (resp. G. Aresu, Unit 1)

Axis C.3: Simulations of specific observations with Ariel (resp. G. Micela, Unit1)

 

PARTICIPANTS

 

UNIT 1

G. Micela – Responsible

G. Aresu

C. Cecchi Pestellini

A. Maggio

R. Muscolino

A. Petralia

R. Spinelli

 

UNIT 2

F. Saija – Responsible

G. Cassone

M.A. Iatì

K. Mrazikova