A Catalogue of Interstellar Material Delivery From Nearby Debris Disks

Abstract

We modeled the trajectories of material ejected from 20 nearby debris disk stars, including Epsilon Eridani (Ran), Vega, Fomalhaut, and Beta Pictoris, within a simulated Milky Way potential in order to quantify their contribution to the population of interstellar material entering the solar system. Our simulations show that material from each of these 20 systems is currently to be expected within our planetary system. We calculate expected fluxes of both macroscopic interstellar objects (ISOs, $\geq100~$m), which could be detected by telescopic surveys, and smaller meteoroids ($\geq200~$microns), which could manifest as meteors in Earth's atmosphere. We estimate that the ISO population originating from these debris disks and currently within the inner solar system is on the order of ~2, only a fraction of the expected total ISO population but nonetheless likely to be discovered by Rubin. Meteors in Earth's atmosphere from these systems are expected as well, but current methods, both radar and video, might require decades to collect even a single event. Our sample is found to be rich in relatively low excess velocity particles compared to the broader expected ISO population, which might make them harder to distinguish observationally from bound objects in some cases. These results provide a framework for linking detections of interstellar material to their astrophysical origins, offering new opportunities to probe the composition and dynamical history of nearby planetary systems.

Figures (65)

• Figure 1: The left figure shows the ejection velocities vs the time spent traveling in the ISM of the simulated particles that enter our Oort cloud from all the systems. The right figure shows the arrival velocity vs arrival time of the simulated particles that enter our Oort cloud from all the systems. The complete figure set (20 images) displaying the data for each individual system separately is displayed in Appendix \ref{['append:A:heat']}.
• Figure 2: The heliocentric equatorial radiant for the close approaches at the time of their closest Solar approach ("Arrival Time"), with the current "effective radiant" of each debris disk system corresponding to it's apparent velocity relative to the Sun. The arrival directions of the three confirmed km-scale interstellar objects (ISOs), the direction of the local interstellar cloud (LIC) upstream direction of interstellar dust (ISD), the Solar apex with respect to the Local Standard of Rest (LSR) and within the Milky Way are also included, along with the direction towards the Galactic Center (see Table \ref{['tab:ISO']}). The heat density is in a log-scale for the number of simulated particles transferred to the solar system. The complete figure set (20 images) displaying the data for each individual system separately is displayed in Appendix \ref{['append:A:Rad']}.
• Figure 3: The top plot shows the expected current population of $\geq 100~$m particles in the inner solar system. The bottom plot is the current flux of $\geq 200~\mu$m particles at the Earth.
• Figure 4: This is a zoomed-in version of the radiant plot in Figure \ref{['fig:radiant']}, focusing on the direction in which 1I/'Oumuamua arrived. HD 38858 and HD 166 are the only systems plotted, to show the comparison in the radiant of their particles arrival directions. These particles are colored by their arrival velocity $v_{\infty}$.
• Figure 5: These are histograms of all simulated particles arriving at the solar system, weighted according to their contribution to the flux at Earth (see Section \ref{['sec:flux']}) but with no size dependence. Heliocentric velocity is computed at 1 au ($v_{hel,1au}$) and eccentricities ($e$) with an assumed perihelion at 1 au. Note the log scale on the y-axis. The complete figure set (20 images) displaying the data for each individual system separately is displayed in Appendix \ref{['append:A:vel_e']}.