The core of neutron stars involve such high densities that its matter cannot be reproduced in laboratories. There is however a chance to probe the interior of those compact stars via observation of macroscopic parameters such as the mass, the radius, the moment of inertia or the tidal deformability. We propose to give insight in the consequences of using nuclear models calculated non...
Lancé en mars 2016, et en phase opérationnelle depuis mars 2018, le satellite ExoMars Trace Gas Orbiter (TGO) embarque plusieurs spectromètres ultra performants à la recherche de gaz traces dans l'atmosphère martienne -- dont le plus emblématique est probablement le méthane. La détection passée du méthane par d'autres instruments fait l'objet de nombreuses controverses, qui ne sont toujours...
Introduction: The Saturn's Semi-Annual Oscillation (SSAO) observed by Cassini is a source of debate within the community, because of its similarities (sometimes conflicting) with both the terrestrial Quasi-Biennial Oscillation (QBO) and the terrestrial Semi-Annual Oscillation (SAO). As the QBO, the downward propagation of the SSAO occurs almost to the tropopause (Schinder et al. 2011). In...
Binary neutron star mergers offer a new and independent means of measuring the Hubble constant by combining the gravitational-wave-inferred source luminosity distance with its redshift obtained from electromagnetic follow-up. This method is limited by intrinsic degeneracy between the system distance and orbital inclination in the gravitational-wave signal. Observing the afterglow counterpart...
The Giant Radio Array for Neutrino Detection (GRAND) is a project dedicated to the radio detection of ultra-high energy cosmic rays, gamma rays and neutrinos. It aims at deploying a radio array of 200 000 antennas over 200 000 km2 in mountainous regions with 20 subarrays of 10 000 antennas in several favorable locations around the world. The objective is to detect inclined (θ> 65°) particle...
Long-duration gamma-ray bursts (GRBs) are produced after the death of very massive stars and can be used to trace the formation of stars inside the host galaxy. Thus, their rate might constraint the evolution of star formation throughout the cosmic times, especially at high-redshift where the trend is still under debate. However, previous works on GRB host galaxies at low redshift bring to...
How Mars was during its first billion years is one of the most intriguing question in our understanding of the Solar System. The planet was host of a tremendous amount of liquid water flowing on the surface throughout the Noachian era, approximatively 4Gya. Geomorphological observations is the main evidence for liquid water since valley networks and lakes are still visible on the surface,...
Under the action of gravity, matter in the largest scales is assembled to form a gigantic network composed of nodes, filaments, walls and voids, that is called the cosmic web. According to numerical simulations, around 50% of the total mass of the Universe might reside in the cosmic filaments, thus tying our understanding of matter to that of filaments. However, since these large-scale...
Black hole astrophysics has taken a dramatic leap forward in recent years thanks to the detection of gravitational waves from merging stellar-mass black holes and the first image of the shadow of the supermassive black hole M87*, opening up the exciting opportunity to probe physics in curved spacetime. To this end, it is of prime importance to have an accurate description of how matter and...
The formation of stars plays a central role in the evolution of the interstellar medium of galaxies,
characterized by complex multi-scale mechanisms. In large hyperdense filaments generated by Galactic
collisions between molecular clouds, cloud fragments called dense cores form, then collapse, converting
their material in protostars. In order to survive this collapse and efficiently accrete...
We study intermittency of turbulence in the young solar wind at 0.17 au with NASA/Parker Solar Probe during the first perihelion. We use a merged FIELDS/Search Coil and Fluxgate Magnetometers data for magnetic field, SWEAP/SPC instrument for ions and RFS/FIELDS quasi thermal noise data for electrons parameters to characterize the plasma environment. The merged magnetic waveforms have 3.4 ms...
Mars has long been considered a planet with high astrobiological interests. Scientific research has shown that the Martian surface, due to its resemblance with Earth environments in its early history, could have seen the emergence of life. Exploratory missions, such as the one conducted by the rover Curiosity since 2012, have deployed scientific tools to find chemical and mineral evidence of...
Galaxy clusters are the largest gravitationally bound structures in the Universe, and are believed to form by accretion of galaxies and mergers with smaller groups of galaxies. Clusters have generally in their center a very massive galaxy (BCG, the Brightest Cluster Galaxy), which is located at the bottom of the cluster gravitational potential well, and has grown by accreting gas as well as...
La mission Solar Orbiter a été lancée avec succès en février 2020. Elle emporte une charge utile de 10 instruments dédiée à l'étude du Soleil et de son influence sur l'héliosphère. La phase de recette en vol s'est achevée en juin 2020. Après une première manœuvre d'assistance gravitationnelle avec Vénus en décembre, la sonde est maintenant sur une trajectoire qui l'amènera au plus près du...
In the context of recent and upcoming large-sky galaxy surveys, it is essential to automatically identify features of the Cosmic Web and, in particular, its filamentary pattern. In this presentation, we introduce T-ReX, a framework allowing the extraction of a principal graph from the observed set of galaxies, even in case noisy and heteroscedastic sampling. Based on a regularised mixture...
We present an atmospheric characterisation of two intermediate-sized planets: HD 106315 c (R$_{\rm P}$=4.98±0.23 R⊕) and HD 3167 c (R$_{\rm P}$=2.74±0.11 R⊕) whose results have been published in the ARES IV article, i.e Guilluy et al 2020. We analysed spatially scanned spectroscopic observations obtained with the G141 grism (1.125 - 1.650 μm) of the Wide Field Camera 3 (WFC3) onboard the...
Dust is omnipresent within Mars’s atmosphere and at its surface. These small (micrometer-sized) particles are one of the major features of Mars modern climate and may also represent a key factor controlling some current surface properties such as composition and activity. Some dust characteristics are still imperfectly unknown, such as the link between dust storms and the seasonal dark flows...
The galactic center (GC) is one of the most actively surveyed region for very high energy photons (noted VHE, over 100 GeV), by the High Energy Stereoscopic System (H.E.S.S) in our case. In addition to a diffuse emission in the central few 100 pc, one the strongest sources in the gamma ray sky, HESS J1745-290, is located at the GC, and is compatible with Sgr A*, the supermassive black hole at...
In this talk I will discuss how we can infer cosmological information from the analysis of galaxy clusters. I will consider currently available data, in particular galaxy clusters detected in the mm wavelengths, and propose a forecasts analysis for future missions.
We analyze proper motions from the Hubble Space Telescope (HST) and the second Gaia data release along with line-of-sight velocities from the MUSE spectrograph to detect imprints of an intermediate-mass black hole (IMBH) in the center of the nearby globular cluster NGC 6397. For this, we use the new MAMPOSSt-PM Bayesian mass-modeling code, along with updated estimates of the surface density...
Mars is known to present a widespread absorption band in the 3 µm spectral range. Related to water or aqueous hydration of a mixture, it has been used in previous studies to retrieve the surface hydration of the Red Planet, using observations of the OMEGA instrument onboard Mars-Express, that has been providing a global mapping of the Martian surface in the $0.3-5.1$ µm spectral range from...
Even before the discovery of the first exoplanet in 1995, radio observations inspired by the intensity of Jupiter’s radio emissions had begun. They proved to be extremely difficult, but also motivated the development of ever larger antenna arrays. The theory rather predicts emissions at low radio frequencies and of very low intensity. But the predictions are subject to large uncertainties on...
Near Earth Asteroids represent a real danger for the Earth. An impact of a Potentially Hazardous Asteroid could have catastrophic consequences. The knowledge of the actual dynamic of Potential Hazardous Asteroids is essential for the purpose of an international program of planetary defense. In this respect, accurate astrometric measurements acquired over a large time span are crucial to...
