A likely planet-induced gap in the disc around T Cha


Type
Article
Change log
Authors
Hendler, NP 
Pinilla, P 
Pascucci, I 
Pohl, A 
Mulders, G 
Abstract

jats:titleAbstract</jats:title> jats:pWe present high-resolution (0.11 × 0.06 arcsec2) 3 mm ALMA observations of the highly inclined transition disc around the star T Cha. Our continuum image reveals multiple dust structures: an inner disc, a spatially resolved dust gap, and an outer ring. When fitting sky-brightness models to the real component of the 3 mm visibilities, we infer that the inner emission is compact (≤1 au in radius), the gap width is between 18 and 28 au, and the emission from the outer ring peaks at ∼36 au. We compare our ALMA image with previously published 1.6 μm VLT/SPHERE imagery. This comparison reveals that the location of the outer ring is wavelength dependent. More specifically, the peak emission of the 3 mm ring is at a larger radial distance than that of the 1.6 μm ring, suggesting that millimeter-sized grains in the outer disc are located farther away from the central star than micron-sized grains. We discuss different scenarios to explain our findings, including dead zones, star-driven photoevaporation, and planet-disc interactions. We find that the most likely origin of the dust gap is from an embedded planet, and estimate – for a single planet scenario – that T Cha's gap is carved by a 1.2MJup planet.</jats:p>

Description
Keywords
planets and satellites: detection, planets and satellites: formation, planet-disc interactions, protoplanetary discs, circumstellar matter
Journal Title
Monthly Notices of the Royal Astronomical Society: Letters
Conference Name
Journal ISSN
1745-3925
1745-3933
Volume Title
475
Publisher
Oxford University Press (OUP)
Sponsorship
Science and Technology Facilities Council (ST/N000927/1)