ALMA and VLA Observations of EX Lupi in Its Quiescent State

Jacob Aaron White , Á. Kóspál , A. G. Hughes , P. Ábrahám , V. Akimkin , A. Banzatti , L. Chen , F. Cruz-Sáenz de Miera , A. Dutrey (1) , M. Flock , S. Guilloteau (1) , A. S. Hales , T. Henning , K. Kadam , D. Semenov , A. Sicilia-Aguilar , R. Teague , E. I. Vorobyov

1 M2A 2020

Extreme outbursts in young stars may be a common stage of pre-main-sequence stellar evolution. These outbursts, caused by enhanced accretion and accompanied by increased luminosity, can also strongly impact the evolution of the circumstellar environment. We present ALMA and VLA observations of EX Lupi, a prototypical outburst system, at 100 GHz, 45 GHz, and 15 GHz. We use these data, along with archival ALMA 232 GHz data, to fit radiative transfer models to EX Lupi's circumstellar disk in its quiescent state following the extreme outburst in 2008. The best fit models show a compact disk with a characteristic dust radius of 45 au and a total mass of 0.01 M$_{\odot}$. Our modeling suggests grain growth to sizes of at least 3 mm in the disk, possibly spurred by the recent outburst, and an ice line that has migrated inward to $0.2-0.3$ au post-outburst. At 15 GHz, we detected significant emission over the expected thermal disk emission which we attribute primarily to stellar (gyro)synchrotron and free-free disk emission. Altogether, these results highlight what may be a common impact of outbursts on the circumstellar dust.

Domaines: Planète et Univers [physics]

Jacob Aaron White, Á. Kóspál, A. G. Hughes, P. Ábrahám, V. Akimkin, et al.. ALMA and VLA Observations of EX Lupi in Its Quiescent State. The Astrophysical Journal, 2020, 904 (1), pp.37. ⟨10.3847/1538-4357/abbb94⟩. ⟨hal-03066039⟩