A Huge Hydrogen Halo Envelops The Milky Way

Gazing on 732,225 galaxies with the 2.5-meter telescope of the Sloan Digital Sky Survey has revealed the veil of diffuse hydrogen gas enshrouding the Milky Way. After combining this staggering number of spectra — recorded patterns of wavelengths revealing clues about the nature of a cosmic target — astronomers Huanian Zhang and Dennis Zaritsky report the first detections of diffuse hydrogen wafting about in a vast halo surrounding the Milky Way. [Read More]

Super Galaxy Cluster verifies Kinetic Sunyaev-Zel'dovich Predictions

Caltech and Jet Propulsion Lab scientists observing a high-speed component of a massive galaxy cluster, observed the effect, a change in the cosmic microwave background due to interaction with massive moving objects. This means that for the first time in a single object, the previously predicted kinetic Sunyaev-Zel’dovich effect has been detected. Shown in the image here, the galaxy cluster MACS J0717.5+3745 is an unusually dynamic one. It also has a total mass greater than a million billion times the mass of the sun. [Read More]