News 2018

Nov 08, 2018
Outstanding results from this Japanese X-rays observatory

Despite a short period of activity, the japanese space agency (Jaxa) Hitomi satellite has shown its full potential by delivering relevant information’s on several celestial objects. In a series of works based on these observations and gathered in an issue of the review Publications of the Astronomical Society of Japan (PASJ), the Hitomi collaboration (among it researchers from the Astrophysical Department of CEA-Irfu Saclay) presents results that take advantage of the exceptional spectral resolution of the SXS spectrometer, one of the payload instrument. At the heart of this work is a detailed study of the dynamics of plasma in the center of an active galactic nucleus, of the ejecta of several supernova remnants, of the composition of matter in a binary system or the search for X and radio correlations in the Crab pulsar thanks to the high temporal resolution. Performed during the verification and calibration phase of the instruments before the satellite failed, these observations and the quality of the results confirm the community's choice on the instruments and the high potential of the high resolution X-rays spectroscopy. The Hitomi team is currently preparing its successor, Xrism (X-Ray Imaging and Spectroscopy Mission) and ESA is on its side working on the Athena project, a major X-rays observatory in which CEA is deeply involved

 

Read more in : Haute résolution pour le satellite Hitomi (in French)

Nov 07, 2018

A prototype of the MXT camera arrived at the CNES in Toulouse on 25 October 2018. This is the Structural and Thermal Model (STM), which will be integrated into the telescope that will be sent to China to be mounted on the SVOM satellite Qualification Model.


The objective of this model is to validate the thermo-mechanical design of the camera. It also makes it possible to check the manufacturing and assembly capacity of the various components, which represent more than 1,000 elements. The model realized includes all the camera subassemblies with a good level of representativeness of the flight model, both on its external design (interfaces with the telescope) and on its internal design (harnesses, connectors...). The electrical parts (detector, electronic boards, motor) are replaced by weights and heaters to simulate their mechanical and thermal behaviour. 

Sep 26, 2018

X-ray photons were detected for the first time in late August 2018 with an engineering model of the SVOM MXT focal plane. This is an important step towards the validation of the design of the detection chain.
The MXT telescope, for Microchannel X-ray Telescope, will be flown on board the SVOM satellite, a collaborative project between France (CNES) and China (CAS, CNSA) to study gamma-ray bursts. It aims at detecting soft X-rays (0.2 to 10 keV) at during the early phases of the afterglow emission, and at providing an accurate (smaller than 1 arc minute) position of the burst. Irfu is in charge of the design and realization of the telescope camera, integrating a pnCCD (provided by MPE) X-ray imaging spectrometer assembled on a dedicated ceramic board. The flight model of the detector must be integrated into the camera in one year from now.



 

Apr 09, 2018

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. The entire set of data will henceforth serve as a reference for the international scientific community. Fourteen articles, making up the largest ever set of scientific results in this field, are published on April 9, 2018 in a special issue of the journal Astronomy & Astrophysics.

Oct 01, 2018
Impressing results from a large X-ray catalog of galaxy clusters

Using the ESA's XMM-Newton observatory, an international team, led by Marguerite Pierre of the Astrophysics Department of CEA-Irfu, has revealed the latest results of the XXL survey, the largest observation program X-ray produced to date by the XMM satellite. The second batch of data just published in a special issue of the journal Astronomy & Astrophysics, includes information on 365 galaxy clusters and 26,000 active galactic nuclei (AGN). By deep examination of two major regions of the sky, the XXL sounding is the first X-ray study to detect enough clusters of galaxies and AGN to trace the large-scale structure of the Universe and its evolution. in time with unprecedented details.

Read more in : Dessiner l'univers: les rayons X apportent une nouvelle lumière (in French)

Feb 05, 2018
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. This interaction shows that Stephan's Quintet is still the scene of generalized galactic cannibalism, in contradiction with the current theoretical predictions, which will therefore have to be revised. These results, from a team from the Strasbourg Astronomical Observatory, the CEA Astrophysics Department and the Lund Observatory (Sweden) are published in the Monthly Notices of the Royal Astronomical Society issue of January 2018.

 

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