A SIGNIFICATIVE FRACTION OF BARYONS RESIDE IN THE FILAMENTS OF THE COSMIC WEB

(Credit: NASA, ESA, and E. Hallman (University of Colorado, Boulder)

Observations of the cosmic microwave background indicate that baryons (protons, neutrons, etc., - the ordinary matter just to understand) occupies only 5% of the total energy content of the Universe (95% is dark matter and dark energy). However in the local universe approximately half of this "ordinary" matter it has never been observed.

A group of astrophysicists
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to know more:
(http://arxiv.org/abs/1512.00454)
(http://www.nature.com/nature/journal/v528/n7580/full/nature16058.html)
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has experimentally verified that the missing mass (ordinary) does not fill the space homogeneously but it is concentrated in large-scale filamentary structures that make up the so-called cosmic web with temperatures between 10^5 to 10^7 degrees. This gas has been heated up by the cluster's gravitational pull and is now feeding its core. The filamentous structures intersect at the nodes creating a structure that visually recalls the network of neurons of the nervous system.

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GAMMA-RAY EMISSION FROM THE SNR HB3

Image: At a distance of about 20,000 light years, G292.0+1.8 is one of only three supernova remnants in the Milky Way known to contain large amounts of oxygen. These oxygen-rich supernovas are of great interest to astronomers because they are one of the primary sources of the heavy elements (that is, everything other than hydrogen and helium) necessary to form planets and people. The X-ray image from Chandra shows a rapidly expanding, intricately structured, debris field that contains, along with oxygen (yellow and orange), other elements such as magnesium (green) and silicon and sulfur (blue) that were forged in the star before it exploded. Credit: NASA/CXC/SAO The processes of particles acceleration to very high energies from the supernova shock region and diffusion in the interstellar medium of such particles has not been well understood so far. Gamma-ray observations in the GeV regime are a powerful probe of these mechanisms

Boulevard of Broken Rings

Credit: ESO/Perrot This Picture illustrates the remarkable capabilities of SPHERE (the Spectro-Polarimetric High-contrast Exoplanet REsearch instrument), a planet-hunting instrument mounted on ESO's Very Large Telescope (VLT) in Chile: It shows a series of broken rings of dust around a nearby star. These concentric rings are located in the inner region of the debris disc surrounding a young star named HD 141569A, which sits some 370 light-years away from us. In this image we see what is known as a transition disc, a short-lived stage between the protoplanetary phase, when planets have not yet formed, and a later time when planets have coalesced, leaving the disc populated only by any remaining - and predominantly dusty - debris. What we see here are structures formed of dust, revealed for the first time in near-infrared light by SPHERE - at a high enough resolution to capture remarkable detail! The area shown in this image has a diameter of just 200 times the Earth–Sun distan...

The Milky Way's rotation curve out to 100 kpc and its constraint on the Galactic mass distribution

Image: This annotated artist’s impression shows the Milky Way galaxy. The blue halo of material surrounding the galaxy indicates the expected distribution of the mysterious dark matter. Credit: ESO/L. Calçada In a recent paper (Huang et al. 2016) the rotation curve (RC) of the Milky Way out to ~100kpc has been constructed using ~16,000 primary red clump giants (PRCGs) in the outer disk selected from the LSS-GAC and the SDSS-III/APOGEE survey, combined with ~5700 halo K giants (HKGs) selected from the SDSS/SEGUE survey.

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