Characterizing Accretion Mechanisms across the Brown Dwarf and Planetary Mass Regimes

Recent discoveries of accreting brown dwarfs (BD) and exoplanets have placed new importance on understanding the mechanisms that control their formation. Accretion mechanisms are well understood for stars, and substellar objects have been assumed to operate similarly; however, simulations suggest that accretion rates (Ṁ) of substellar objects are controlled by their formation mechanisms. I will discuss my work disentangling physical and systematic effects in substellar accretion properties using the Comprehensive Archive of Substellar and Planetary Accretion Rates (CASPAR). CASPAR consists of >1000 measured Ṁs from ~800 T-Tauri stars, BDs, and planetary mass companions (PMC), making it the largest compiled sample of Ṁs for these objects to-date. I systematically rederive all physical and accretion properties using Gaia distances, consistent ages and evolutionary models, and a single set of line to total-accretion-luminosity scaling relations. This update decreases the M-Ṁ relation scatter by 7%, indicating that the remaining broad scatter is attributable to physical effects such as age and variability. I will also present the detection of the first NIR accretion signatures from a protoplanet, Delorme 1 (AB)b, and found from Paγ, Paβ, and Brγ line emission, it accretes at a rate of 3-4x10-8 MJ/yr. Ratios of its NIR emission lines are most consistent with planetary shock accretion models, and its high Ṁ suggests disk fragmentation formation