Tag Archive for 'Circumgalactic medium'

Our Milky Way Galaxy is surrounded by an enormous halo of plasma (seen in blue in this artists’ rendition). Image credit: NASA / CXC / M.Weiss / Ohio State / A. Gupta et al.

Milky Way’s Halo is Disk-Like and Clumpy, Study Shows

Oct 20, 2020 by News Staff

Using X-ray data from NASA’s HaloSat minisatellite, astronomers have found that our Milky Way Galaxy is surrounded by a clumpy halo of hot gases that...

This image from the eROSITA X-ray telescope shows the energetic Universe. As eROSITA scans the sky, the energy of the collected photons is measured with an accuracy ranging from 2% - 6%. To generate this image, in which the whole sky is projected onto an ellipse (so-called Aitoff projection) with the center of the Milky Way in the middle and the body of our Galaxy running horizontally, photons have been color-coded according to their energy (red for energies 0.3-0.6 keV, green for 0.6-1 keV, blue for 1-2.3 keV). The red diffuse glow away from the galactic plane is the emission of the hot gas in the vicinity of the Solar System (the Local Bubble). Along the plane itself, dust and gas absorb the lowest energy X-ray photons, so that only high-energy emitting sources can be seen, and their color appears blue in the image. The hotter gas close to the Galactic center, shown in green and yellow, carries imprinted the history of the most energetic processes in the life of the Milky Way, such as supernova explosions, driving fountains of gas out of the plane, and, possibly, past outburst from the now dormant supermassive black hole in the center of the Milky Way. Piercing through this turbulent, hot diffuse medium, are hundreds of thousands of X-ray sources, which appear mostly white in the image, and uniformly distributed over the sky. Among them, distant active galactic nuclei are visible as point sources, while clusters of galaxies reveal themselves as extended X-ray nebulosities. In total, about one million X-ray sources have been detected in this image. Image credit: Jeremy Sanders, Hermann Brunner & the eSASS team / Max Planck Institute for Extraterrestrial Physics / Eugene Churazov & Marat Gilfanov, IKI.

eROSITA X-Ray Telescope Captures Hot, Energetic Universe

Jun 19, 2020 by News Staff

A new all-sky image from the eROSITA X-ray telescope onboard the Spectrum-Roentgen-Gamma (SRG) space observatory contains over one million objects, about...

Milky Way’s Halo Hotter than Previously Thought

Jun 2, 2020 by News Staff

Using deep X-ray observations from ESA’s XMM-Newton Observatory, astronomers have discovered that Milky Way’s halo — a large cloud of ionized...

A volume rendering of the ionized gas wind in the Makani galaxy. Two of the dimensions are spatial, and the third is velocity. The colors trace the velocity axis, shown by the arrow at center. The approximate locations of the two proposed outflow episodes are labeled. Image credit: Jim Geach, David Tree & Peter Richardson, University of Hertfordshire.

Astronomers Observe Giant Outflow of Gas Extending Far Beyond Compact Galaxy

Oct 31, 2019 by News Staff

The direct evidence of the role of galactic winds — ejections of gas from galaxies — in creating the so-called circumgalactic medium has been...