A new direction for dark matter research: intermediate mass compact halo objects

TL;DR

This paper explores the potential of gravitational microlensing to detect intermediate mass compact halo objects (MACHOs) as a form of dark matter, emphasizing Earth's motion effects on microlensing signals.

Contribution

It proposes a novel observational strategy using Earth's motion-influenced microlensing curves to confirm MACHOs as dark matter candidates.

Findings

Earth's motion affects microlensing light curves.

Microlensing can directly detect MACHOs in the galactic halo.

Strategy could confirm dark matter composition within years.

Abstract

The failure to find evidence for elementary particles that could serve as the constituents of dark matter brings to mind suggestions that dark matter might consist of massive compact objects (MACHOs). In particular, it has recently been argued that MACHOs with masses > 15 solar masses may have been prolifically produced at the onset of the big bang. Although a variety of astrophysical signatures for primordial MACHOs with masses in this range have been discussed in the literature, we favor a strategy that uses the potential for gravitational microlensing of stars outside our galaxy to directly detect the presence of MACHOs in the halo of our galaxy. We point out that the effect of the motion of the Earth on the shape of the microlensing brightening curves provides a promising approach to confirming over the course of next several years that dark matter consists of MACHOs.