The European Spatial Agency retains the mission of exploration of galaxies
The SPICA infrared space telescope has been shortlisted by the European Space Agency (ESA) to participate in the final competition which will see in September 2021 the choice of the next mission of medium size ESA (M5 mission). SPICA is a large infrared telescope (diameter 2.5 m) fully cooled to a temperature of only a few degrees above absolute zero.
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.
THESEUS pre-selected for an ESA M5 mission
On May 7, 2018, the European Space Agency (ESA) announced the three selected space missions, out of the 25 proposed, for the fifth ESA middle class mission in its scientific program Cosmic Vision, whose launch date is planned in 2032. One of these three missions is the THESEUS project (Transient High-Energy Sky and Early Universe Surveyor), a project developed in recent years by a large European consortium in which the Astrophysics Department-AIM Laboratory of CEA-Irfu plays a major role.
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.
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.
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.
TO BE TRANSLATED Après une sélection sévère, les premières cibles d'observation du télescope spatial James Web (JWST) qui doit être lancé au printemps 2019, viennent d'être dévoilées.
The James Webb Space Telescope (JWST) has reached a key milestone with the completion of cryogenic tests on its telescope and instruments. Working within an international consortium, France, in particular the CEA, the CNRS and the CNES, has played a key role in the development, for the scientific successor to the Hubble and Spitzer space telescopes, of the Mid-InfraRed Imager (MIRIM) that will enable it to see wavelengths of 5 to 28 microns.  
Planetary migration: magnetic or tidal effects ?
A large part of the exoplanets known today are in very close orbit around their star, allowing very intense interactions between the planets and the host star. An international collaboration, led by researchers from Department of Astrophysics-AIM Laboratory at CEA-Irfu, has shown that these planets in close orbits migrate rapidly, due to the combined effect of tidal forces and magnetic forces. This study provides essential elements for understanding the formation and evolution of star-planet systems.
The discovery of a new type of gravitational wave
Using a range of detectors developed with the participation of the CEA, physicists at CEA-Irfu have scrutinized the region from which the gravitational wave was detected on August 17, 2017 by LIGO-VIRGO facilities. Unlike the four previous detections of waves of the same type discovered since 2015, this new vibration of space, called GW170817, is of different origin. It does not result from the fusion of two black holes but of two densest known stars, the neutron stars.
The Cherenkov Telescope Array (CTA) consortium brings together 1300 scientists from 32 countries. They have published their scientific aims in a document over 200 pages long. This is the result of several years of work, and includes contributions from approximately fifteen Irfu researchers involved in X-ray and gamma-ray observatories (Fermi, Integral, XMM-Newton, H.E.S.S., etc.).
An international team including two researchers from the Department of Astrophysics-Laboratory AIM of CEA-Irfu detected for the first time the presence of the CH+ molecule in distant galaxies of the young universe, thanks to the large ALMA interferometer. The presence of this particular molecule demonstrates the existence around the young galaxies of large turbulent reservoirs of low-density cold gas.
The study of solar vibrations reveals the astonishing behavior of the thermonuclear center of the Sun
By analyzing more than 16 years of data collected by the GOLF instrument onboard the SOHO satellite, an international collaboration involving two researchers from the Department of Astrophysics-Laboratory AIM of CEA-IRFU has demonstrated a rapid rotation of heart of the sun. For the first time, researchers were able to indirectly determine the properties of solar gravity waves, oscillations affecting the innermost layers of the star.
The secret of the star magnetic cycles
Thanks to new numerical simulations, a scientific team led by researchers from the Astrophysics Department-Laboratory AIM of CEA-Irfu has succeeded in explaining why the magnetic field of the Sun reverses every 11 years. Scientists have highlighted the existence of a strong feedback between the star magnetic field and its internal rotation profile, with temporal modulations that ultimately determine the period of the cycle.
A new link between the dynamics of galaxies and the activity of their central black hole
Using images obtained with the Hubble Space Telescope, an international team of researchers led by Yu-Yen Chang from the Service d’Astrophysique-Laboratoire AIM at CEA–IRFU showed that some galaxies hosting an active nucleus are much more compact than those without nuclear activity. This discovery sheds new light on the physical processes driving the evolution of super-massive black holes at the center of distant galaxies.
New study simulates how tornado-shaped flow in a dynamo strengthens the magnetic field
An international team, including researchers from the Department of Astrophysics (CEA-Irfu) and Department of Solid State Physics (CEA-Iramis), conducted an unprecedented simulation based on the Von-Kármán-Sodium (VKS) dynamo experiment (CEA-CRS-ENS) [1], to examine more closely how the liquid vortex created in liquid sodium by the propellers of VKS device can generate a magnetic field.
An old galaxy with unexpected features
An international team including a researcher from the AIM Laboratory-Astrophysics Department of CEA-Irfu has just discovered an elliptical galaxy of completely unexpected shape within the galaxy cluster Abell 2670. Deep observations made by the new MUSE multi-spectrograph recently put into operation at the European Observatory VLT in Chile revealed a highly deformed elliptical galaxy, showing in particular long gas tails and star formation regions normally absent in this type of galaxy.
The PILOT astrophysics experiment has been launched the 17th April under a stratospheric balloon from Alice Springs in central Australia. The aim is to observe the polarization of the emission of dust particles present in the interstellar medium of our Galaxy and the nearby galaxies. With a mass of nearly one ton, PILOT [1] uses the biggest balloons launched by the National Center for Space Studies (CNES).
Key role of the gaseous phase underlined by numerical simulations and analytical approach
The proto-clusters, which are the birth sites of stars, are formed non-uniformly inside molecular clouds of the interstellar medium. Studying the steps leading to the collapse of pre-stellar dense cores is essential to understanding the star formation. Using both numerical simulations carried out on massively parallel computers and an analytical approach, two researchers from the Astrophysics Department / AIM Laboratory of CEA-Irfu, Y.-N. Lee and P.
Mysterious alignment of the rotation axis of stars in two clusters
The stars do not play dice! It is the extraordinary discovery that the researchers of the Department of Astrophysics-Laboratoire AIM of the CEA-Irfu made by succeeding in determining the orientation in the space of the axis of rotation of stars belonging to two clusters of stars, thanks to asteroseismology. About 70% of the observed stars have perfectly aligned axes of rotation, in formal contradiction with the star formation models which predict that these axes of rotation should be randomly distributed.
First light of the ArTéMiS camera at two wavelengths and first results on interstellar filaments
The new ArTéMiS submillimetric camera was successfully re-installed in June 2016 on the APEX telescope in the Atacama desert in Chile. In its new configuration, with an increased number of detectors, this camera can simultaneously obtain images at 350 and 450 microns.
An exceptional parade of exoplanets
Seven planets of terrestrial size and moderate temperature gravitate around the star Trappist-1, a small cool red star located at 40 light years from Earth. Better: at least three of them are in conditions compatible with the presence of liquid water on their surface.
In an article published in the Astrophysical Journal, an international team including two researchers from the Astrophysics Department- AIM Laboratory at CEA-Irfu, successfully detected the trace of solar oscillations in the light reflected by the planet. These very Low luminosity variations originate from the vibrations of the solar surface. The data were obtained from the Kepler/K2 (NASA) satellite which observed for 49 days continuously the planet located at an average distance of 4.5 billion kilometers from Earth.
At the center of a small galaxy located about 1.8 billion light-years from Earth, a giant black hole swallowed a star for about a decade, which is exceptionally longer than any observed episode of this kind. This discovery was made by an international collaboration involving an astrophysicist from IRFU, thanks to a trio of orbiting X-ray telescopes.
Astrophysicists from IRFU have studied the evolution over time of the "wind" in stars similar to the Sun. They were able to perform 3D computer simulations of these stellar winds based, in particular, on spectropolarimetric measurements of the surface magnetic field of the stars. 
The most energetic events of the Universe
A team of researchers led by Rémi Adam (Laboratoire Lagrange - OCA, UCA, LPSC Grenoble, CNES), Iacopo Bartalucci and Gabriel Pratt (Astrophysics Department- AIM Laboratory at CEA-Irfu) obtained for the first time an image of the gas velocity in colliding clusters of galaxies with NIKA [1], a new generation millimeter camera, at the focus of the 30 m diameter IRAM telescope of Pico Veleta (Spain).


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