News 2018

June 2018

In ultra-relativistic heavy ion collisions at CERN's LHC accelerator, a new state of matter is formed: the quark-gluon plasma (QGP). It is a kind of very dense and hot "soup" containing only the most elementary constituents of matter. A few microseconds after the Big Bang, the Universe would have passed through this state. Because of the interactions between its constituents, the QGP flows like a fluid.

May 2018

New statistical methods reveal the finest details of the Universe
A team led by University College London (UCL), in collaboration with the Astrophysics Department of CEA-Irfu, has significantly improved the analysis of dark matter maps in the Universe with new methods of data analysis. The maps produced by this analysis demonstrate the power of these new innovative methods for analyzing future large data sets such as those expected from the upcoming EUCLID cosmological mission. These results are published in the MNRAS journal.
Dark matter constitutes about 85% of the total matter content of the Universe. However, its nature is still unknown. The H.E.S.S. observatory located in Namibia scrutinizes the central region of our Galaxy to search for mono-energetic gamma rays from the collision of hypothetical WIMPs, primary elementary particles that are among the leading candidates for dark matter. The search carried out with 10 years of observations of the center of our galaxy with phase 1 of H.E.S.S.

April 2018

The laws of the birth of stars questioned
An international team led by researchers from the CNRS, Grenoble Alpes University and the Astrophysical Department /AIM Laboratory of CEA-Irfu suggests a radical modification on our ideas on the formation of stars. The accuracy of observations provided by the Atacama Large Millimeter Array (ALMA) in Chile has made it possible to measure the quantity of massive star-forming cores in a very active far-away region of our galaxy, and thus to show that their proportion is higher than expected.
The mass distribution of the different stars formed from a collapsing gas cloud has just been successfully reproduced by two researchers from the Astrophysics Department/AIM Laboratory of CEA-Irfu. The collapse of a gas cloud of 1000 solar mass has been reconstructed thanks to numerical simulations, varying the density and the influence of turbulence.
The HESS international collaboration, to which CNRS and CEA contribute, has published the results of fifteen years of gamma ray observations of the Milky Way. Its telescopes installed in Namibia have studied populations of pulsar wind nebulae and supernova remnants, as well as microquasars, never before detected in gamma rays. These studies are supplemented by precise measurements such as those of the diffuse emission at the center of our Galaxy.
Detection by ALMA of polarized dust emission in the protostar B335
An international team led by the Department of Astrophysics/AIM Laboratory of CEA-Irfu has just shown for the first time that the magnetic field plays a fundamental role in the collapse of proto-stars. Based on observations from the Atacama Large Millimeter Array (ALMA) in Chile, researchers measured the polarization of dust in the B335 protostar. This polarization, emission of light in a preferred direction, results from the alignment of the dust grains under the influence of the magnetic field.

February 2018

The very first moments of a star explosion
An unprecedented observation of a supernova, an explosion of a massive star, was captured in its early days by an amateur astronomer, at the exact moment when the supernova became visible in the sky.
A theoretical breakthrough paves the way for anticipation of solar storms
A single phenomenon could control all solar flares. This is what researchers from the Ecole Polytechnique, CNRS, CEA-Irfu and Inria have just proposed in an article in the front page of the journal Nature on February 8, 2018. They highlighted the presence of a reinforced "cage" in which a "magnetic cord" develops, an entanglement of twisted magnetic lines of force at the origin of the solar flares.
A galactic cohabitation more hectic than expected
The MegaCam camera developed at CEA-Irfu has revealed previously unsuspected structures within the famous Stephan Quintet, a spectacular combination of five galaxies. The discovery of a very large red halo, consisting of old stars, centered on one of the elliptical galaxies, NGC 7317, shows that the group of galaxies is still in very strong interaction, an aspect totally ignored in previous studies.

January 2018

Giant galaxies that no longer form stars have 100 times more gas than expected.
By succeeding for the first time to analyze the light of nearly 1000 very distant elliptical galaxies, more than 10 billions light-years away, a team of researchers including three astrophysicists from the Astrophysics Department of CEA-Irfu has just revealed that these galaxies of the beginning of the universe contain a lot of gas but do not form stars. A real enigma that challenges our understanding of the evolution of these giant galaxies.
An interactive video has made it possible to reconstruct the trajectories of 1,400 galaxies, including the Milky Way, over distances reaching up to 100 million light years.


Retour en haut