Published on 22 January 2019
Jean d'Alembert grant program

Louis Rodriguez is a researcher at the CEA at the Department of Astrophysics. Thanks to the program of Alembert University Paris-Saclay, he welcomed Albrecht Poglitsch in 2018, researcher at the Max Planck Institute and space instrumentalist. Together, they collaborate on the production of B-BOP, a far-infrared instrument incorporating the latest generation of detectors, which is expected to fly on a European satellite in 2032, thus helping to unravel the mysteries of the Universe.

The Department of Astrophysics (CEA) develops innovative technologies in response to the scientific needs of astrophysicists. Thus, it imagines and build instruments embedded on the satellites in areas of radiation inaccessible from the ground (gamma rays and X) or partially accessible (from infrared to millimeter).

B-BOP, detectors from the year 2030

B-BOP (B for magnetic field, Bo for Bolometer and P for Polarimeter) is one of three instruments that will be shipped on the Spica satellite supported by European and Japanese space agencies. B-BOP will be at the forefront of technology: its detectors allow to see polarization and gives access to magnetic fields. "I seized the opportunity of Alembert's Paris-Saclay program to appeal to Albrecht Poglitsch, whose contribution is decisive in designing this new instrument," says Louis Rodriguez.

Once selected, a team of 50 people will be formed around B-BOP, largely involving the forces of the Université Paris-Saclay ecosystem (IAS, C2N, ...).

At the forefront of spatial instrumentation

B-BOP takes root in the late 2000s when a very innovative type of detector arrays (wavelength beyond infrared) is developed: the submillimeter. A camera developed at the Department by Louis Rodriguez is then integrated into the PACS instrument which is embedded on the Herschel satellite and of which Albrecht Poglitsch was the Principal Investigator. The scientific return of this instrument has been considerable in many fields of astrophysics and a solid complicity has developed between the two researchers during these ten years of work.

How are stars born?

After two generations of space observatories in the field, the mystery of star formation remains. "We had known for more than thirty years that these were formed, out of sight, by gravitational collapse of molecular clouds, large opaque volumes in visible light. These often reveal, in infrared, an intense activity of formation of clusters of young stars" explains Louis Rodriguez. But the images produced by Herschel show that these clouds are in fact made up of filaments of gas and matter of almost uniform size, which, according to certain conditions, drain the matter towards what are called "nurseries of stars". ". But other observations of the Herschel satellite, targeting distant galaxies, revealed that this process was much more effective two or three billion years ago. What structures this filamentary network? What is reducing the efficiency of the process today?

Detect the magnetic field

Some suggest that the galactic or extragalactic magnetic field could be the hitherto invisible structuring element of star formation. Now this magnetic field could be revealed by the polarization of light. It is in this context that the first bolometers (heirs of those of Herschel, but sensitive to polarization) were designed by Louis Rodriguez and which B-BOP is the latest generation.

"There is nothing comparable in the world, together Albrecht and Louis, we only make a few instruments in a lifetime! " Beyond this first year in Saclay to develop B-BOP, the German researcher continues, as a foreign scientific advisor, to be an integral part of the team.

FOCUS Welcome Laboratory

The Department of Astrophysics is subordinate to the CEA's Directorate of Basic Research, including the Institute for Research on the Fundamental Laws of the Universe (IRFU) in Saclay.

Specialist in the exploration of the Universe, and witness of the vertiginous twists and turns of the past three decades, Louis Rodriguez, an engineer-researcher at CEA, has been working since the 90s with NASA, ESA and CNE in what is became over the years the Department of Astrophysics. "One of the specificities of the CEA was, initially, the manufacture of nuclear detectors adapted to very high energy radiation. At the end of the 1980s, the infrared detectors developed at Leti completed the spectral range available for European space observation, in particular through the ESA ISO satellite. The Department of Astrophysics has made a major contribution to the discoveries made in recent years in the space field.


Department of Astrophysics CEA Saclay, CEA DRF / Irfu,

FOCUS D’Alembert Grant

Albrecht Poglitsch has spent his entire career at the Max Planck Institute for Extraterrestrial Physics in Garching. In 2016, he received the Gay-Lussac Humboldt Prize from the Ministry of Higher Education and Research with the support of the Academy of Sciences. This award recognizes eminent scientists active in Germany and having close collaborations with France. In 2000, Dr. Albrecht Poglitsch is the PI (Principal Investigator) of the PACS instrument, one of the three instruments of the European Space Agency (ESA) Herschel satellite.

Albrecht Poglitsch is happy to collaborate with the teams of the Department he has known for 30 years. "There are few permanent research positions in Germany, many are in the industry, but that's not for me!, he says. At the end of his career, the German scientist is still motivated by the "challenge of experimentation and collaboration with people of different nationalities. Beyond the B-BOP project that occupies me, I have a lot of links here, I continue to do astronomy with people with whom I made discoveries.”