Late accretion offers pathway to misaligned disk around the planet-hosting IRAS 04125+2902

TL;DR

The paper addresses the misaligned transition disk observed in the IRAS 04125+2902 binary system. It employs 3D hydrodynamical simulations with the FARGO3D code to model a late infall of a gas cloudlet onto the binary, forming second-generation disks around both stars with substantial misalignment relative to the binary. The results show a primary disk forming at about 300 AU with a mass of roughly 2.1×10^-3 solar masses and a secondary disk at ~9.3×10^-5 solar masses, with a mass-weighted misalignment around 58 degrees and a warp that persists after 4.4 binary orbits; the orientation is broadly consistent with the observed disk inclination under reasonable assumptions. This scenario demonstrates that environmental mass inflow can drive disk-planet misalignment without requiring additional massive companions, highlighting a key mechanism in disk evolution and planet formation.

Abstract

We present a 3D hydrodynamical simulation of the accretion of a gas cloudlet onto the IRAS 04125+2902 binary system, where the 3-Myr primary hosts a transiting planet. We demonstrate that such an accretion event can naturally produce a circumstellar disk that is misaligned with respect to the rest of the system, consistent with the observed misaligned transition disk. In the model, the prescribed orbital plane of the cloudlet is largely retained by the resulting circumstellar disk after undergoing gravitational interactions with the secondary during the initial accretion. After ~4.4 binary orbits, a disk with $R_d=300~\mathrm{AU}$ has formed around the stellar primary made of ~13% of the cloudlet mass, $M_\mathrm{d,p}=2.1\times 10^{-3}~\mathrm{M}_\odot$. The companion also retains some of the cloudlet's mass and forms a disk with $M_\mathrm{d,c}=9.3\times 10^{-5}~\mathrm{M}_\odot$, though only the transition disk around the primary has been observed. Our findings highlight the importance of considering mass inflow onto protoplanetary disk for their evolution.

Figures (7)

• Figure 1: Gas column density at $t_\mathrm{end}=94.8k$. The camera angle is such that the position angle of the binary orbit corresponds to the observed value. The orbit is indicated by the white dotted line, and the white arrows indicate the initial infall direction.
• Figure 2: Orientation of the primary disk. The angle between the angular momentum vector of a ring at the radius indicated on the horizontal axis and the binary orbit is shown as a solid blue line. The mass-weighted average value is given by the dashed blue line. For reference, the disk's cumulative mass is indicated by the dashed black line, whereas the dotted vertical black line denotes the limiting radius for the mass-weighting.
• Figure 3: ALMA Band 6 observations of the circumstellar disk around the primary. The contour lines show the $10\sigma$ and $15\sigma$ continuum emission. The top left panel shows the 1.3mm continuum emission map, the top right panel the CO peak intensity map, the bottom left panel the CO moment 0 map, and the bottom right panel the CO moment 1 map.
• Figure 4: Total masses of the primary (blue line) and secondary (orange line) disks, as well as the initial cloudlet mass $M_\mathrm{c}$ (black dashed line) and total mass of bound gas (black solid line).
• Figure 5: Time series of the gas column density found in the simulation. The camera perspective is chosen as in Fig. \ref{['fig:figure_1']}. The white arrows denote the initial infall direction, and the white dashed line represents the orbit of the secondary star.