arXiv subjects

Danai Polychroni

Publications and source records attributed to Danai Polychroni.

3 recordsLinked to original sources

arXiv2026

Unveiling Complex Chemistry in Planet-forming Disks with the SKAO

The chemical composition of planets is inherited from that of the natal protoplanetary disk at the time of planet formation. In recent years, we have made huge progress in characterizing disk chemistry. (Sub-)millimeter interferometers, such as ALMA, allowed us to detect emission lines from simple to complex organic molecules and to probe their radial and vertical distribution in disks. On the other hand, JWST has started to unveil the composition of disk ices, and line emission from the innermost disk regions. The advent of SKA will open new domains in the field, by observing emission lines from heavier molecules including heavy carbon chains and rings, and prebiotic molecules with peak emission in the cm range. Moreover, SKA will probe molecular emission from regions which are obscured by dust opacity at mm wavelengths, hence from the disk midplane, and often from the inner 30 au region. These observations will constrain the initial conditions for disk evolution and planet formation, allowing us to predict the chemical composition of the forming planets and their atmospheres. Comparison with forthcoming results on exoplanet atmospheres and on the chemistry of pristine bodies in the Solar System will provide new hints on the origin and evolution of planetary systems including our own.

astro-ph.SR↗

arXiv2026

Substructures in Planet-Forming Disks with the SKAO

Disks of gas and dust orbiting young stars are the arenas and material reservoirs for planet formation. Over the past decade, multiwavelength observations, from infrared to radio, have resolved the spatial distribution of hundreds of protoplanetary disks in nearby star-forming regions, revealing a diverse zoo of substructures. These substructures are morphological features such as rings, gaps, spirals, vortices, asymmetries, warps, or clumps that trace variations in density, temperature, or composition relative to an otherwise smooth distribution of gas and dust. Many unknowns persist as to the origin of these substructures, their role in planet assembly, and their true properties. SKA-Mid Band 5b continuum observations, offering angular resolutions of $\sim 0.05''$ ($\sim 0.15''$) with AA4 (AA*) at $12.5$ GHz / $2.4$ cm, will enable new progress at this frontier. In this chapter, we outline the open questions in the field of disk substructure that SKA-Mid is uniquely poised to address, with a lens on dust thermal emission.

astro-ph.EP↗

arXiv2022

Dust resurgence in protoplanetary disks due to planetesimal-planet interactions

Observational data on the dust content of circumstellar disks show that the median dust content in disks around pre-main sequence stars in nearby star forming regions seem to increase from about 1 Myr to about 2 Myr, and then decline with time. This behaviour challenges the models where the small dust grains steadily decline by accumulating into larger bodies and drifting inwards on a short timescale (less than about 1 Myr). In this Letter we explore the possibility to reconcile this discrepancy in the framework of a model where the early formation of planets dynamically stirs the nearby planetesimals and causes high energy impacts between them, resulting in the production of second-generation dust. We show that the observed dust evolution can be naturally explained by this process within a suite of representative disk-planet architectures.

astro-ph.EP↗