Pasquale Serpico in Science&Vie

The 1149 issue (June 2013) of the magazine Science & Vie devotes a special article to cosmic rays, these particles that travel through the galaxy and end up bombarding the earth. Our colleague Pasquale Serpico was one of two experts that was consulted for the write-up.

Since their discovery in 1912, the origin of these ionizing particles of very high energy has long remained a mystery. Much evidence has now accumulated to trace back their origin to the explosion of massive stars known as supernovae. The latest results from the Fermi space telescope seem to confirm this hypothesis.

Planck Results

 Congratulations to the Planck Team and to our colleague Julien Lesgourgues for their remarkable study of the temperature fluctuations of the CMB. This study has now given us the oldest map of the Universe, going back 400,000 years after the Big Bang, a snapshot with exceptional detail that will remain a reference for cosmological analyses. We now have a very accurate reconstruction of the composition of the "cosmic soup" which, in combination with other cosmological observables, offers a remarkably simple and coherent framework within the "standard cosmological model" thus providing very interesting constraints on relevant aspects of particle physics such as the number and the mass of neutrinos.

This wealth of data also revealed a few anomalies. In the months and years ahead, we will learn from these analyses whether we should go beyond the standard cosmological model. Furthermore, other ongoing analyses of the data address the polarization of the radiation. This will improve the chances of detecting other phenomena such as the presence of a diffuse background of gravitational waves.

Pierre Salati in Pour la Science (Scientific American)

 The issue 426 (April 2013) of the magazine Pour la Science, the French edition of Scientific American, is devoted to a lengthy article on dark stars. It is written by Katherine Freese (University of Michigan, USA), Paolo Gondolo (University of Utah, USA) and our colleague Pierre Salati.

Several measurements in astrophysics and cosmology indicate the presence of a new type of matter, dark matter. Dark matter represents no less than 85% of the matter content of the Universe. The most plausible hypothesis is that dark matter consists of new, electrically neutral and weakly interacting particles.

Many theories describing physics beyond the standard model of particle physics incorporate dark matter candidates. Dark stars, that are,  oddly enough, brighter than a thousand suns, draw their energy from the annihilation of these dark matter candidates.

Serpico awarded the CNRS Bronze Medal

Our colleague Pasquale Serpico is awarded the 2013 CNRS bronze medal. This is in recognition of his work and achievements is astroparticle physics and in cosmology.