Debris Disc Substructures Induced by Secular Planetary Perturbations
Abstract
Observations of debris discs have the potential to provide valuable information about massive planets perturbing them gravitationally. In this work, we explore the evolution of the azimuthally-averaged (or axisymmetric) surface density (ASD) --- a characteristic routinely derived from observations --- in a disc that is secularly perturbed by an inner planet. We develop a detailed analytical understanding of ASD evolution and verify it using a novel numerical framework {\sc debrispy}, which we make publicly available. With these tools we show that in a secularly evolving disc ASD develops a set of sharp features --- sharp peaks at eccentricity nulls and finite discontinuities at caustic points where particle periastra or apoastra pile up --- marching out through the disc as it ages. We probe the dependence of these features on planetary eccentricity, ratio of the free to forced particle eccentricity, and underlying radial mass distribution, showing in particular that more eccentric planets produce more prominent ASD features. Convolution with the PSF of realistic observations (as well as the non-zero random free eccentricity of debris) smooths out these features, but they can still be detectable in high-resolution observations. The radial locations of secular ASD peaks follow a particular, well-defined pattern, which should unambiguously point to their secular nature in observations. We illustrate how both detection and non-detection of such secular features in observed discs can be used (in combination with other constraints) to measure or constrain key parameters of perturbing planets (even those not yet detected) --- mass, semi-major axis and eccentricity.
Related
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- A double debris disc around a white dwarf sculpted by two planetary bodies
- Third-order scalar induced gravitational waves during a matter-dominated era: secular growth and implications for primordial black hole domination
- Effects of Poisson Isocurvature Perturbations on Induced Gravitational Waves
BibTeX
@misc{rafikov2026debris,
title = {{Debris Disc Substructures Induced by Secular Planetary Perturbations}},
author = {Roman R. Rafikov and Deniz Akansoy and Antranik A. Sefilian},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2607.08750},
eprint = {2607.08750},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2607.08750},
note = {CC BY-NC-SA 4.0},
}
RIS
TY - UNPB
TI - Debris Disc Substructures Induced by Secular Planetary Perturbations
AU - Roman R. Rafikov
AU - Deniz Akansoy
AU - Antranik A. Sefilian
PY - 2026
DA - 2026/10/18
PB - arXiv
DO - 10.48550/arxiv.2607.08750
UR - https://arxiv.org/abs/2607.08750
AB - Observations of debris discs have the potential to provide valuable information about massive planets perturbing them gravitationally. In this work, we explore the evolution of the azimuthally-averaged (or axisymmetric) surface density (ASD) --- a characteristic routinely derived from observations --- in a disc that is secularly perturbed by an inner planet. We develop a detailed analytical understanding of ASD evolution and verify it using a novel numerical framework {\sc debrispy}, which we make publicly available. With these tools we show that in a secularly evolving disc ASD develops a set of sharp features --- sharp peaks at eccentricity nulls and finite discontinuities at caustic points where particle periastra or apoastra pile up --- marching out through the disc as it ages. We probe the dependence of these features on planetary eccentricity, ratio of the free to forced particle eccentricity, and underlying radial mass distribution, showing in particular that more eccentric planets produce more prominent ASD features. Convolution with the PSF of realistic observations (as well as the non-zero random free eccentricity of debris) smooths out these features, but they can still be detectable in high-resolution observations. The radial locations of secular ASD peaks follow a particular, well-defined pattern, which should unambiguously point to their secular nature in observations. We illustrate how both detection and non-detection of such secular features in observed discs can be used (in combination with other constraints) to measure or constrain key parameters of perturbing planets (even those not yet detected) --- mass, semi-major axis and eccentricity.
ER -