Towards a Comprehensive View of Accretion, Inner Disks, and Extinction in Classical T Tauri Stars: An ODYSSEUS Study of the Orion OB1b Association

Caeley V. Pittman , Catherine C. Espaillat , Connor E. Robinson , Thanawuth Thanathibodee , Nuria Calvet , John Wendeborn , Jesus Hernández , Carlo F. Manara , Fred Walter , Péter Ábrahám , Juan M. Alcalá , Sílvia H. P. Alencar , Nicole Arulanantham , Sylvie Cabrit (1) , Jochen Eislöffel , Eleonora Fiorellino , Kevin France , Manuele Gangi , Konstantin Grankin , Gregory J. Herczeg , Ágnes Kóspál , Ignacio Mendigutía , Javier Serna , Laura Venuti

1 LERMA - Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique

The coevolution of T Tauri stars and their surrounding protoplanetary disks dictates the timescales of planet formation. In this paper, we present magnetospheric accretion and inner disk wall model fits to near-UV (NUV) to near-IR (NIR) spectra of nine classical T Tauri stars in Orion OB1b as part of the Outflows and Disks around Young Stars: Synergies for the Exploration of ULLYSES Spectra (ODYSSEUS) survey. Using NUV-optical spectra from the Hubble UV Legacy Library of Young Stars as Essential Standards (ULLYSES) Director's Discretionary Program and optical-NIR spectra from the PENELLOPE VLT Large Programme, we find that the accretion rates of these targets are relatively high for the region's intermediate age of 5.0 Myr; rates are in the range of (0.5-17.2) × 10^-8 M _☉ yr^-1, with a median value of 1.2 × 10^-8 M _☉ yr^-1. The NIR excesses can be fit with 1200-1800 K inner disk walls located at 0.05-0.10 au from the host stars. We discuss the significance of the choice in extinction law, as the measured accretion rate depends strongly on the adopted extinction value. This analysis will be extended to the complete sample of T Tauri stars being observed through ULLYSES to characterize accretion and inner disks in star-forming regions of different ages and stellar populations.

Keywords: Pre-main sequence stars; Stellar accretion; Stellar accretion disks; Protoplanetary disks; Reddening law; Interstellar extinction; Hubble Space Telescope; Very Large Telescope; Astrophysics - Solar and Stellar Astrophysics; Astrophysics - Earth and Planetary Astrophysics

Domains: Sciences of the Universe [physics]; Astrophysics [astro-ph]

Caeley V. Pittman, Catherine C. Espaillat, Connor E. Robinson, Thanawuth Thanathibodee, Nuria Calvet, et al.. Towards a Comprehensive View of Accretion, Inner Disks, and Extinction in Classical T Tauri Stars: An ODYSSEUS Study of the Orion OB1b Association. The Astronomical Journal, 2022, 164, ⟨10.3847/1538-3881/ac898d⟩. ⟨insu-03851599⟩