HEAPOW: Dark Matter Bump in the Night? (2014 Jun 30)

Find out the latest thinking about our universe.
User avatar
bystander
Apathetic Retiree
Posts: 18891
Joined: Mon Aug 28, 2006 2:06 pm
Location: Oklahoma

HEAPOW: Dark Matter Bump in the Night? (2014 Jun 30)

Post by bystander » Tue Jul 01, 2014 2:24 am

Image HEAPOW: Dark Matter Bump in the Night? (2014 Jun 30)

X-ray telescopes like the Chandra X-ray Telescope not only take exquisite X-ray images of cosmic objects, like the image of the Perseus cluster of galaxies above, but also measure the energy of the emitted X-rays. The X-ray spectrum, i.e. the distribution of X-rays with energy, is a vital clue to the source of the emission. Electrons spiralling around magnetic fields, particles of hot gas bumping into each other, bound electrons in heavy elements jumping from one orbit to another around the atomic nucleus, all have their distinctive signatures. A new study of over 70 clusters of galaxies using Chandra and the XMM-Newton X-ray telescope has uncovered something strange and unexpected: a bump of emission at an X-ray energy where there should be no bump. A representative bump from the Perseus cluster is shown in the inset above, highlighted by the white oval. Astronomers are not sure what this strange bump might mean. It's possible that the bump is an instrumental artifact, though this is unlikely since the feature is seen by both Chandra and XMM-Newton. An exciting possibility is that the feature might arise from the decay of dark matter particles called sterile neutrinos.

CXC: Perseus Cluster: Mysterious X-ray Signal Intrigues Astronomers
viewtopic.php?t=33002

Detection of an Unidentified Emission Line in the Stacked X-Ray Spectrum of Galaxy Clusters - Esra Bulbul et al An unidentified line in X-ray spectra of the Andromeda galaxy and Perseus galaxy cluster - Alexey Boyarsky et al
<< Previous HEAPOW High Energy Astrophysics Picture of the Week Next HEAPOW >>
Know the quiet place within your heart and touch the rainbow of possibility; be
alive to the gentle breeze of communication, and please stop being such a jerk.
— Garrison Keillor