When two observations share some common information, they can be “cross-correlated” to extract it. In today’s example, we discover what the matter halos and energetic phenomena in the Universe have in common through a cross-correlation.
In the next few years, gravitational wave detectors are expected to start finding mergers of compact objects. But their resolution is limited to large areas of the sky. Fast galaxy surveys are needed to aid in the task of locating the source more precisely, but how fast can they go?
The distribution of matter in the Universe has much to say about its constituents and evolution. Can the distribution of voids also help us understand the Universe?
Cosmic rays hit the Earth and produce showers of particles that can be detected on the ground. Understanding where these cosmic rays come from can help scientists pin down their sources and construct models for the magnetic field in our neighborhood.
Gas in clusters is predicted to cool quickly, but observations suggest otherwise. What prevents the gas from cooling? The authors explore the incidence and impact of heating by active galactic nuclei.