Exoplanets & Exomoons

A Dust-Trapping Ring in the Planet-Hosting Disk of Elias 2-24

By Keith Cowing
Status Report
June 22, 2024
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A Dust-Trapping Ring in the Planet-Hosting Disk of Elias 2-24
High resolution ALMA images of Elias 24 at 1.3 mm and 3 mm, with an RMS of 0.35 K (19 µJy beam−1 ) at 1.3 mm and 0.33 K (9 µJy beam−1 ) at 3 mm. The white ellipse in the bottom left shows the beam size of the image, corresponding to 0.036′′ × 0.034′′ (5.0 au × 4.7 au) at 1.3mm, 0.060′′ × 0.058′′ (8.2 au × 7.9 au) at 3mm. The white hash at the bottom right is 10 au. — astro-ph.EP

Rings and gaps are among the most widely observed forms of substructure in protoplanetary disks.

A dust-trapping ring would provide a promising environment for solid growth and possibly planetesimal production via the streaming instability.

We present evidence of dust trapping in the bright ring of the planet-hosting disk Elias 2-24, from the analysis of 1.3 mm and 3 mm ALMA observations at high spatial resolution (0.029 arcsec, 4.0 au).

We leverage the high spatial resolution to demonstrate that larger grains are more efficiently trapped and place constraints on the local turbulence (8×10−4<αturb<0.03) and the gas-to-dust ratio (Σg/Σd<30) in the ring.

Using a scattering-included marginal probability analysis we measure a total dust disk mass of Mdust=13.8+0.7−0.5×10−4 M. We also show that at the orbital radius of the proposed perturber, the gap is cleared of material down to a flux contrast of 10−3 of the peak flux in the disk.

Radial profiles of the dust properties in the disk around Elias 24. The left column shows our results for p = 2.5, while the right column shows p = 3.5. The orbital radius of the candidate companion from Jorquera et al. (2021) is shown with a green dashed line and the ring location is shown with a magenta dashed line. Top: The dust surface density profile. Notice the increase in surface density at the ring location and the significant decrease in the gap. Center: The maximum grain size profile, which also increases at the ring location, indicating potential grain growth in the ring. Bottom: The temperature profile distributions. The blue dotted line shows the prior temperature profile given by Equation 1, with 1σ Gaussian standard deviations shown as blue dashed lines. — astro-ph.EP

Adolfo S. Carvalho, Laura M. Perez, Anibal Sierra, Maria Jesus Mellado, Lynne A. Hillenbrand, Sean Andrews, Myriam Benisty, Tilman Birnstiel, John M. Carpenter, Viviana V. Guzman, Jane Huang, Andrea Isella, Nicolas Kurtovic, Luca Ricci, David J. Wilner

Comments: 18 pages, 12 figures, accepted to ApJ
Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Solar and Stellar Astrophysics (astro-ph.SR)
Cite as: arXiv:2406.12819 [astro-ph.EP] (or arXiv:2406.12819v1 [astro-ph.EP] for this version)
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Submission history
From: Adolfo Carvalho
[v1] Tue, 18 Jun 2024 17:37:41 UTC (8,926 KB)

Explorers Club Fellow, ex-NASA Space Station Payload manager/space biologist, Away Teams, Journalist, Lapsed climber, Synaesthete, Na’Vi-Jedi-Freman-Buddhist-mix, ASL, Devon Island and Everest Base Camp veteran, (he/him) 🖖🏻