Atmospheric parameters sub-WG

 Context and Objectives

The purpose of this sub-WG is to produce atmospheric parameters (Teff, logg, [Fe/H]) for the targets to be observed by the Ariel mission. Since the stars span a wide range in parameter space, ranging from cool M dwarfs to hot A stars, we employ different methods for the determination of their parameters. To ensure maximum homogeneity in the determination of parameters, we used the same atmospheric models and atomic data for the spectral lines wherever possible. In addition, all methods use a combination of spectral analysis, with high-signal-to-noise and high-resolution spectra, and photometric information from the Gaia mission. These spectro-photometric methods enable improved parameter determination, particularly of surface gravity. 

We also ensured that we always had overlap and benchmark samples (such as stars in star clusters) in which to apply different methods to guarantee the homogeneity, precision and accuracy of our analysis. 

In addition, this sub-WG provides orbital parameters, such as the mean Galactocentric radius and the orbit eccentricity, crucial to investigate the displacement of stars across the Galactic disc, and thus the original site of formation of  the stars and their planetary systems. 

The coordinators

The sub-WG members

Jesus Maldonado (INAF- Osservatorio Astrofisico di Palermo, Palermo, Italy ) - Jesus is in charge for the determination of the stellar parameters of M type stars

Heleri Ramler (Tartu Observatory, Tartu, Estonia ) - Heleri is responsible for the determination of the parameters of A type stars, with Teff > 7000 K

Diego Bossini  (INAF - Osservatorio di Padova, Padova, Italy) and Tiago Campante (IA, Porto)   - Diego and Tiago provide an accurate photometric determination of surface gravity, an essential step in the iterative spectrophotometric method. 

Anna Brucalassi (INAF - Osservatorio Astrofisico di Arcetri, Florence, Italy)  - Anna led the work of comparing the various analysis techniques that resulted in the definition of the adpted spectrophotometric method.

Katia Biazzo (INAF - Osservatorio Astronomico di Roma, Rome, Italy) - Katia is an expert in the determination of stellar parameters and she performed quality control and checks on the analysis. 

Colin Folsom (Tartu Observatory, Tartu,  Estonia) - Colin is an expert of spectral analysis of hot stars 

Sandipan Borthakur  (Tartu Observatory, Tartu, Estonia)