Speaker
Description
Circumstellar disk evolution and planet formation are closely linked to accretion processes and to the environments where young stars form. In this work, we combine observational and methodological advances to quantify how clustered environments and early protostellar phases regulate accretion and, ultimately, the planet-forming potential of disks. First, we studied external photoevaporation in the young massive cluster Trumpler 14 within the Carina Nebula Complex. Multiple O-type stars in this region produce strong farultraviolet (FUV) radiation, which can heat disk surfaces and drive thermal winds that remove gas from the outer regions of disks around nearby low-mass stars. This process may reduce disk mass and lifetime, alter the gas-to-dust ratio, and truncate disks to a few tens of AU, potentially limiting planet formation. To investigate these effects, a new methodology was developed using archival integral-field spectroscopy from VLT/MUSE. Stellar spectra were extracted from the MUSE data and analyzed using a Conditional Invertible Neural Network (cINN) to infer stellar parameters such as effective temperature, surface gravity, extinction, and optical veiling. Combined with J-band photometry, these measurements provide stellar luminosities, ages, and masses, enabling further analysis of how strong FUV irradiation affects disk indicators such as veiling and near-infrared excess. In the second part, we extend the cINN framework to embedded Class I protostars, this time using near-infrared (NIR) spectra. Because these objects are strongly obscured and veiled, conventional diagnostics are uncertain. Our method models NIR emission as the combination of stellar photospheric light, accretion-heated disk emission, and accretion shocks. A grid of synthetic spectra is created to train the cINN, and the model is then validated on observed JHK spectra. The goal of this study is to derive stellar accretion properties from these objects and gain insight into the initial stages of star/disk formation and evolution.
