Astronomers Detect Dark Matter Sub-Halo in Milky Way Using Pulsar Accelerations

Astronomers have identified a dark matter sub-halo within the Milky Way by analyzing the accelerations of pulsars, marking a significant advancement in understanding dark matter distribution. Dr. Sukanya Chakrabarti, the Pei-Ling Chan Endowed Chair in the College of Science at The University of Alabama in Huntsville, led the research team that utilized both binary and solitary pulsars to detect this sub-halo.

Pulsars, rapidly spinning neutron stars emitting regular radio pulses, serve as precise cosmic clocks. By measuring slight deviations in their timing, the team inferred gravitational influences from unseen masses. Their analysis revealed a dark matter sub-halo with an estimated mass of approximately 24.5 million solar masses, located near the Sun.

To confirm that this signal wasn't due to regular matter, the researchers examined data from the Gaia space observatory and large surveys of hydrogen gas, finding no evidence that the gravitational signal could come from stars or gas.

This discovery provides a proof of principle for probing nearby, low-mass sub-halos and has implications across many fields of astrophysics—from understanding the nature of dark matter to galaxy formation.

The study is published in the journal Physical Review Letters.