A dynamical measurement of the disk mass in Elias 2-27

• Published in: arXiv.org
• Main Authors: Veronesi, Benedetta, Paneque-Carreno, Teresa, Lodato, Giuseppe, Testi, Leonardo, Pérez, Laura M, Bertin, Giuseppe, Hall, Cassandra
• Format: Paper Journal Article
• Language: English
• Published: Ithaca Cornell University Library, arXiv.org 07.05.2021
• Subjects: Carbon monoxide; Continuum radiation; Emission analysis; Gravitational instability; Gravity; Morphology; Physics - Earth and Planetary Astrophysics; Physics - Solar and Stellar Astrophysics; Planet formation; Planetary rotation; Protoplanetary disks; Star & galaxy formation; Star formation; Stellar age
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.2104.09530

Recent multi-wavelength ALMA observations of the protoplanetary disk orbiting around Elias 2-27 revealed a two armed spiral structure. The observed morphology together with the young age of the star and the disk-to-star mass ratio estimated from dust continuum emission make this system a perfect laboratory to investigate the role of self-gravity in the early phases of star formation. This is particularly interesting if we consider that gravitational instabilities could be a fundamental first step for the formation of planetesimals and planets. In this Letter, we model the rotation curve obtained by CO data of Elias 2-27 with a theoretical rotation curve including both the disk self-gravity and the star contribution to the gravitational potential. We compare this model with a purely Keplerian one and with a simple power-law function. We find that (especially for the \(^{13}\)CO isotopologue) the rotation curve is better described by considering not only the star, but also the disk self-gravity. We are thus able to obtain for the first time a dynamical estimate of the disk mass of \(0.08\pm0.04\,M_{\odot}\) and the star mass of \(0.46\pm0.03\,M_{\odot}\) (in the more general case), the latter being comparable with previous estimates. From these values, we derive that the disk is 17\(\%\) of the star mass, meaning that it could be prone to gravitational instabilities. This result would strongly support the hypothesis that the two spiral arms are generated by gravitational instabilities.