Search arXiv⌕ Search
Home/Archive/arXiv

arXiv · 2508.03624

Radiative Nonideal MHD Simulations of Inner Protoplanetary Disks: Temperature Structures, Asymmetric Winds, and Episodic Surface Accretion

Shoji Mori·Xue-Ning Bai·Kengo Tomida
View original source ↗Read source document ↗Export metadata ↓

Abstract

We perform two-dimensional global magnetohydrodynamic (MHD) simulations including the full nonideal MHD effects (Ohmic diffusion, Hall effect, and ambipolar diffusion) and approximate radiation transport to understand the dynamics and thermal structure of the inner protoplanetary disks (PPDs). We have developed a simple radiative transfer model for PPDs that reasonably treats stellar non-thermal (XUV), stellar thermal (optical/infrared), and re-emitted radiations, reproducing the temperature structures from Monte Carlo radiative transfer. Our simulations show fast one-sided surface accretion ($\sim 10\%$ of Keplerian velocity) and asymmetric disk winds when the vertical magnetic field is aligned with the disk angular momentum. The asymmetry is due to the failure of the wind on the side with the accretion layer. On the accreting surface, clumps are repeatedly generated and accrete, driven by radiative feedback. For the anti-aligned fields, surface accretion becomes more moderate and time-variable, while the winds remain largely symmetric. For the thermal structure, accretion heating does not affect the disk temperature in any of our runs. This is because (1) the accretion energy dissipates via Joule heating at 2--3 gas scale heights, where low optical depth enables efficient radiative cooling, and (2) the winds remove $\gtrsim 10\%$ of the accretion energy. In contrast, the winds enhance radiative heating by elevating the irradiation front. These results highlight the importance of coupling between gas dynamics and radiation transport in PPDs, and provide observable magnetic activities such as fast episodic accretion, wind asymmetry, and molecular survival in XUV-irradiated winds.

Explore related subjects

astro-ph.EPastro-ph.SR

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Shoji Mori, Xue-Ning Bai, Kengo Tomida. 2025-08-05. Radiative Nonideal MHD Simulations of Inner Protoplanetary Disks: Temperature Structures, Asymmetric Winds, and Episodic Surface Accretion. https://doi.org/10.3847/1538-4357%2Fadf8d7

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

Radiating Bondi Flows I: Dimensionless Framework and Constant Opacity Solutions

In this paper, we extend the foundational work of Bondi (1952) to include the effects of radiative feedback in gas-pressure-dominated environments. We construct steady-state spherically symmetric accretion solutions including radiative heating and cooling. Under the simplifying assumption of a constant opacity, the solutions are controlled by four dimensionless parameters: the adiabatic index $γ$, optical depth through the Bondi radius $τ_B$, dimensionless luminosity at infinity $\tilde{L}_\infty$, and a characteristic dimensionless cooling time $β$. We present numerical solutions across the dimensionless parameter space $(τ_B, \tilde{L}_\infty, β)\in [10^{-3}, 10^3]$. Contrary to radiation-pressure-dominated environments, radiative feedback primarily operates to suppress accretion -- particularly at high $τ_B$, $\tilde{L}_\infty$, and/or $β$. We also present analytic descriptions confirming the suppressive nature of this feedback and give the scalings for the accretion rate $\dot{M}\sim \tilde{L}_\infty^{-5/4}$ at large $\tilde{L}_\infty$, $\dot{M}\sim τ_B^{-10/11}β^{-5/11}$ at large $τ_B$, and $\dot{M}\sim (\tilde{L}_\inftyτ_B)^{-5/8}$ for large $\tilde{L}_\inftyτ_B$. We discuss the potential role of convection in these steady-state solutions, and the particular relevance to problems of planet formation where radiative heating is significant, but the system remains in the gas-pressure-dominated regime.

astro-ph.EP↗
arXiv2026

Radiating Bondi Flows II: Giant Planet Accretion Models

In the core accretion model of giant planet formation, the late stages of runaway growth are regulated by the hydrodynamic infall of gas from the protoplanetary disk. For a subset of planet-disk pairings, this scenario is analogous to the classical Bondi problem, which has motivated a Bondi-like parameterization of accretion in some population synthesis models. Existing models and the associated classical Bondi rate however, are predicated upon an adiabatic equation of state. In reality, the planet and its associated accretion shock supply a luminosity that substantially heats the accretion flow. In Paper I of this series, we demonstrate that such radiative feedback can dramatically suppress accretion by orders of magnitude. Here we quantify this effect under realistic planet-forming conditions. We find that for planets forming in an unperturbed disk, accretion is suppressed by 1-2 orders of magnitude interior to $\sim 10$ AU. For planets that open a gap, this feedback is less dramatic and the effect is $\sim$ 1 order in magnitude. We investigate the effect of various assumptions regarding dust opacities, shock efficiency, and planet radius and find this radiative suppression mechanism to be fairly insensitive to these effects. We also perform full time-dependent simulations demonstrating that the associated adverse entropy profiles are accurate and stable to convection. A simple and flexible set of open-source tools are provided to incorporate this radiative feedback into existing accretion models and population synthesis frameworks.

astro-ph.EP↗
arXiv2026

Assessing the Impact of High-Resolution Imaging on Statistical Validation of TESS Planet Candidates

High-resolution imaging is widely used to constrain false-positive scenarios in exoplanet validation, but it is a finite follow-up resource that reaches only a subset of candidates, and its population-level impact on validation outcomes has not been quantified through controlled removal experiments. Using an automated pipeline built on TRICERATOPS, we compute the false-positive probability (FPP) of 443 TESS planet candidates. For the 264 planet candidates with high-resolution imaging observations, we compute FPP with and without the corresponding contrast curves, allowing us to quantify the impact of the additional data. We find that 72% of 68 contrast-curve bearing validated planets would fail validation without their adopted contrast curves. The fraction requiring imaging decreases with increasing planet size, from 100% below $1.7~R_\oplus$ to $33\%$ above $4~R_\oplus$: within our sample and TRICERATOPS-based analysis, the availability of high-resolution imaging directly limits the yield of small-planet validation and the supply of validated targets for atmospheric characterization. Our analysis statistically validates 64 new TESS planets with sizes spanning 0.94 to 7.83 $R_\oplus$ across hosts of spectral type M through F. Four of these are highly amenable to JWST observations based on the transmission and emission spectroscopy metrics, and each achieves validation only with its imaging constraint.

astro-ph.EP↗