Eccentric debris disc morphologies II: Surface brightness variations from overlapping orbits in narrow eccentric discs

Abstract

We present Paper II of the Eccentric Debris Disc Morphologies series to explore the effects that significant free and forced eccentricities have on high-resolution millimetre-wavelength observations of debris discs, motivated by recent ALMA images of HD53143's disc. In this work, we explore the effects of free eccentricity, and by varying disc fractional widths and observational resolutions, show for a range of narrow eccentric discs, orbital overlaps result in dust emission distributions that have either one or two radial peaks at apocentre and/or pericentre. The narrowest discs contain two radial peaks, whereas the broadest discs contain just one radial peak. For fixed eccentricities, as fractional disc widths are increased, we show that these peaks merge first at apocentre (producing apocentre glow), and then at pericentre (producing pericentre glow). Our work thus demonstrates that apocentre/pericentre glows in models with constant free and forced eccentricities can be both width and resolution dependent at millimetre wavelengths, challenging the classical assertion that apocentre/pericentre glows are purely wavelength dependent. We discuss future high-resolution observations that can distinguish between competing interpretations of underlying debris disc eccentricity distributions.

7 pages, 5 figures. Accepted for publication in MNRAS Letters

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Cited by in corpus (5)

• Probing the eccentricity in protostellar discs -- Modeling kinematics and morphologies
• The ALMA survey to Resolve exoKuiper belt Substructures (ARKS): VI. Asymmetries and offsets
• ALMA Reveals an Eccentricity Gradient in the Fomalhaut Debris Disk
• High Resolution ALMA Data of the Fomalhaut Debris Disk Confirms Apsidal Width Variation
• Resolving the large exoKuiper belt of the HD 126062 debris disc and extended gas emission in its vicinity