Dark matter remains one of nature’s greatest mysteries.
Astrophysically, dark matter’s gravity accounts for multiple disparate observations.
From individual, rotating galaxies
to galaxies moving within clusters
to gravitational lensing
to colliding galaxy clusters
to the large-scale cosmic web,
the independent lines of evidence supporting dark matter are overwhelming.
We’ve even determined how it’s distributed within galaxy clusters.
Now, a new method reveals dark matter’s presence more rigorously than ever before.
When galaxies interact within clusters, stars and tidal streams get stripped out.
This catapults stars into the intracluster medium: the space between galaxies.
Although individually unresolvable, those stars still shine, emitting faint intracluster light.
Because dark matter gravitationally attracts those stars, that intracluster light evolves as a dark matter tracer.
Along with lensing signals, this can map out dark matter substructure within galaxy clusters.
This technique has been successfully leveraged previously with Hubble, revealing suspicious and unexpected features.
But now, the JWST offers even greater scientific potential.
Mireia Montes and Ignacio Trujillo analyzed the original JWST deep field for intracluster light.
Additional processing and calibration revealed multiple contributors.
Central mergers and outer accretion create this light.
This “tracing” technique lets us see and map out dark matter as never before.
Mostly Mute Monday tells an astronomical story in images, visuals, and no more than 200 words. Talk less; smile more.