DHp.2.21 — Characterizing the small scale structures in the earliest stages of low-mass star formation

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Aug 10th at 6:00 PM until 6:00 PM

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Author(s): Magnus Vilhelm Persson2, Ewine van Dishoeck2, John Tobin2, Daniel Harsono1, Jes K Jørgensen3

Institution(s): 1. ITA, 2. Leiden University, 3. NBI

In deeply-embedded low-mass protostars, the density and temperature distribution in the inner few hundred AU’s are poorly constrained. In sources where the envelope is less massive, i.e. the Class I stage, disks with Keplerian rotation have been inferred using C18O lines. However, constraining the various disk characteristics turns out to be difficult even in this case. Continuum and molecular line observations of optically thin tracers at very high sensitivity and resolution are needed to constrain the density, temperature and kinematics. Ultimately the assumed structure affects the determination of molecular abundances.
We are attempting to model high-resolution dust continuum radio-interferometric observations of a few deeply-embedded low-mass protostars with a power-law disk model embedded in a spherical envelope.
We model the interferometric visibilities taken with either the Plateau de Bure Interferometer or the ALMA telescope, probing scales down to a few tens of AU in some cases. Given the assumptions, the study shows disk sizes in the deeply-embedded phase that could be slightly larger than typical found in the more evolved Class I sources. The fitting also highlights that models for the physical structure of the inner envelope, on 500-2000 AU scales, needs to be improved. With future high sensitivity observations, we could potentially also be able to constrain any vertical density and temperature structure. In this poster I will present the