A dark matter stream through the solar neighborhood

A stream of dark matter associated with the Sagittarius dwarf galaxy may be passing by the solar system. In direct searches for weakly interacting dark matter particles (WIMPs) in the stream provide a characteristic signature in the recoil spectrum of target nuclei, namely a new yearly modulation limited to low energy recoils. The maximum recoil energy due to stream WIMPs, and thus the proportion of high energy and low energy recoils, are modulated during the year, in a pattern that would be difficult to attribute to laboratory effects. As such, this new pattern may provide an intrinsic way of ascertaining the WIMP nature of a dark matter signal.