- The paper demonstrates that compact stars can capture dark matter particles, enabling constraints on DM properties via observable astrophysical effects.
- It details a model of DM accretion onto white dwarfs in globular clusters, linking changes in stellar luminosity to DM-nucleon interactions.
- The study explores neutron stars as extreme-density environments, where DM accumulation might trigger secondary effects like gravitational collapse.
Compact Stars as Dark Matter Probes
The paper "Compact Stars as Dark Matter Probes" by Gianfranco Bertone and Malcolm Fairbairn examines the potential use of compact astrophysical objects, such as white dwarfs and neutron stars, to set constraints on the properties and density of dark matter (DM). The authors explore the interaction of DM particles with these compact objects and determine how such interactions could manifest observationally.
Capture and Annihilation Processes
The capture of dark matter by stars, particularly compact objects that exert high gravitational pull, is a well-explored mechanism that relies on a finite DM-nucleon cross-section. The captured DM particles, upon falling into such dense stellar environments, may subsequently annihilate with each other. The focus is on Weakly Interacting Massive Particles (WIMPs), a leading candidate for DM. Different potential DM candidates, including WIMPzillas and axions, are briefly considered, but the primary analysis centers on WIMPs due to their well-studied interaction characteristics.
White Dwarfs in Globular Clusters
The paper details a model to examine the potential effects of DM accretion onto white dwarfs, specifically in the globular cluster M4, where unique conditions might amplify detectable signals from such processes. Given the cores of white dwarfs and their known radius and escape velocities, the authors compute the change in luminosity induced by potential DM interactions. Observational data of these cool white dwarfs offer a unique opportunity to constrain the DM-nucleon interaction cross-section, leveraging their low temperatures and the assumption of a DM presence in or around these globular clusters.
Neutron Stars and Dark Matter
Neutron stars provide another compelling environment to paper DM interactions. Despite their relatively small size, their extreme densities make them prime candidates for DM capture studies. While direct observational detection might be challenging due to neutron stars' inherent high temperatures, the authors explore secondary effects such as potential gravitational collapse scenarios if a sufficient DM mass accumulates within the star.
Theoretical and Observational Implications
The implications of this research are twofold: if DM can substantially affect the structure or observable properties of these dense stars, it propels new methods for testing DM theories. Practically, should WIMPs or similarly behaving particles be observed in lab settings, this might offer a new branch of astronomical observation focused on dark matter distributions within stellar environments.
The authors conclude that while capturing these DM-signals is challenging due to the temperature and observational issues with compact objects, the outcome could considerably advance both the understanding of DM distributions in globular clusters and potentially verify experimental findings related to WIMPs. The paper underscores the importance of detailed astrophysical modeling and the synergy between observational astronomy and particle physics in the quest to unravel the mysteries of dark matter.