Year: 2026
Type: article
Abstract: There are millions of undetected black holes wandering through our galaxy. Observatories like Chandra, LIGO, and more recently, Gaia, have provided valuable insights into the configurations of these elusive objects when residing in binary systems. Motivated by these advances, we study, for the first time, the enhanced accretion of metals from the interstellar medium (ISM) onto low-mass companions in binary systems with highly unequal mass ratios, utilizing a series of hydrodynamical simulations. Our study demonstrates that a stellar companion’s metal accretion history from the ISM alone, from its formation to the present, can significantly influence its surface abundance, especially when enhanced by a massive black hole companion. However, this effect is likely only measurable in stars that are still on the main sequence. Once a stellar companion evolves off the main sequence, similar to what has been observed with the Gaia BH3 companion, the initial dredge-up process is likely to erase any excess surface abundance resulting from the metals that were accreted. As we discover more unequal mass ratio binary systems, it is crucial to understand how the observed metallicity of Sun-like companions may differ from their birth metallicity, especially if they are not yet evolved.
Source: The Astrophysical Journal
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $4,499
Funders: European High Performance Computing Joint Undertaking, National Science Foundation, U.S. Department of Energy, University of California, Santa Cruz, University of Wisconsin-Madison, University of Rochester, Heising-Simons Foundation, Norges Forskningsråd, Office of Science, National Nuclear Security Administration, Division of Graduate Education
Awards: REU Site: The Lamat Summer Research Program on High Performance Computing in Astrophysics, WoU-MMA: Multiple Approaches to Multi-Messenger Astronomy, G4393721236, Multiple Approaches to Multiple-Messenger Astronomy, Collaborative Research: Connecting Models to Observations of Tidal Disruption Events, G6464745819, MRI: Acquisition of a High Performance Computer for Computational Science at UC Santa Cruz
OpenAlex ID: W7122666761