Modeling (Sub-)millimeter Scattering Properties of Fractal and Consolidated Porous Particles: Applications to Protoplanetary Disks

arXiv:2605.23680 · astro-ph.EP · Submitted 2026-05-22 · Read on arXiv

Gonzalo Vargas, Daniel Guirado, Carlos Carrasco-Gonzalez, Olga Munoz, Maxim A. Yurkin, Enrique Macias, Jesus M. Jaquez-Dominguez, Francisco J. Garcia-Izquierdo

Instituto de Astrofisica de Andalucia · Instituto de Astrofisica de Andalucia · Instituto de Radioastronomia y Astrofisica, Universidad Nacional Autonoma de Mexico, Morelia, Mexico · Instituto de Astrofisica de Andalucia · Universite Rouen Normandie, INSA Rouen Normandie, CNRS, CORIA UMR 6614, Saint-Etienne-du-Rouvray, France · European Southern Observatory · Instituto de Radioastronomia y Astrofisica, Universidad Nacional Autonoma de Mexico, Morelia, Mexico · Instituto de Astrofisica de Andalucia

astro-ph.EP

Submitted: 2026-05-22

Comments: 18 pages, 8 figures, 8 tables. Accepted for publication in The Astrophysical Journal

License: http://creativecommons.org/licenses/by/4.0/

The gist: We perform light-scattering numerical simulations for two dust populations: (i) consolidated porous particles computed with the discrete dipole approximation (ADDA) and (ii) highly porous aggregate

Terminology

Abstract

We perform light-scattering numerical simulations for two dust populations: (i) consolidated porous particles computed with the discrete dipole approximation (ADDA) and (ii) highly porous aggregate models, including fractal and hierarchical aggregates, computed with the multiple-sphere T-matrix method (MSTM). Using DSHARP optical constants, we compute scattering matrices, cross sections, and effective albedo omega eff for a size distribution n(a) proportional to a q, with q = -3.5, amin = 0.1 micron, and ten wavelengths from 0.87 to 10 mm. We find that increasing porosity strengthens forward scattering and enhances polarization near theta approximately 90 degrees. For compact spheres, P(90 degrees) times omega eff peaks near amax approximately lambda divided by 2 pi and then declines, whereas porous particles show a broader peak extending to larger sizes, keeping polarization-based constraints compatible with amax approximately 1 mm. Porosity also lowers kappa abs at fixed dust mass relative to compact spheres, implying larger inferred dust masses for a given continuum flux.

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