Search Publications

A comparison of the simulations and observations for a nearby spiral arm

Paunzen, Ernst; Piecka, Martin

We present a review of our current understanding of the spiral structure of galaxies, based on the kinematic models.

The analysis is focused on the ability of galactic open clusters to trace the spiral arms, based on the recent data releases from Gaia. For this, a simple 1D description of the motion of spiral arms and clusters is introduced. …

Interrelations between Astrochemistry and Galactic Dynamics

Mendoza, Edgar; Duronea, Nicolas; Ronsó, Daniele +4 more

This paper presents a review of ideas that interconnect Astrochemistry and Galactic Dynamics. Since these two areas are vast and not recent, each one has already been covered separately by several reviews. After a general historical introduction, and a needed quick review of processes like the stellar nucleosynthesis which gives the base to unders…

Magnetic field turbulence in the solar wind at sub-ion scales: in situ observations and numerical simulations

Hellinger, P.; Alexandrova, O.; Matteini, L. +5 more

We investigate the transition of the solar wind turbulent cascade from MHD to sub-ion range by means of a detail comparison between in situ observations and hybrid numerical simulations. In particular we focus on the properties of the magnetic field and its component anisotropy in Cluster measurements and hybrid 2D simulations. First, we address t…

Automatic classification of plasma regions in near-Earth space with supervised machine learning: application to Magnetospheric Multi Scale 2016-2019 observation

Breuillard, Hugo; Lapenta, Giovanni; Dupuis, Romain +3 more

The proper classification of plasma regions in near-Earth space is crucial to perform unambiguous statistical studies of fundamental plasma processes such as shocks, magnetic reconnection, waves and turbulence, jets and their combinations. The majority of available studies have been performed by using human-driven methods, such as visual data sele…

Returning Samples from Enceladus for Life Detection

MacKenzie, Shannon M.; Davila, Alfonso F.; Neveu, Marc +7 more

Evidence suggests that Saturn's icy moon Enceladus has a subsurface ocean that sources plumes of water vapor and ice vented to space from its south pole. In situ analyses of this material by the Cassini spacecraft have shown that the ocean contains key ingredients for life (elements H, C, N, O and possibly S; simple and complex organic compounds; …

Cluster and MMS simultaneous observations of magnetosheath high speed jets and their impact on the magnetopause

Russell, C. T.; Berchem, J.; Dandouras, I. +34 more

Discontinuities in the solar wind, bow shock ripples or ionized dust clouds carried by the solar wind, high speed jets (HSJs) are observed in the magnetosheath. These HSJs have typically a Vx component larger than 200 km s-1 and their dynamic pressure can be a few times the solar wind dynamic pressure. We use a conjunction of Cluster and MMS, cros…

Cosmology with quasars: predictions for eROSITA from a quasar Hubble diagram

Lusso, Elisabeta

The effort for understanding the matter and energy content of the Universe and its evolution relies on different probes, such as cosmic background radiation, cluster lensing, supernovae. Yet, we are still far from grasping what dark matter is made of, and what the physical origin of dark energy is. Our group has developed a technique that makes us…

Using dimensionality reduction and clustering techniques to classify space plasma regimes

Verscharen, Daniel; Walsh, Andrew P.; Rae, I. Jonathan +2 more

Collisionless space plasma environments are typically characterised by distinct particle populations. Although moments of their velocity distribution functions help in distinguishing different plasma regimes, the distribution functions themselves provide more comprehensive information about the plasma state, especially at times when the distributi…

Two Successive Type II Radio Bursts Associated with B-class Flares and Slow CMEs

Chen, Huadong; Ma, Suli

3 From 2018 Oct 12 to 13, three successive solar eruptions (E1-E3) with B-class flares and poor 4 white light coronal mass ejections (CMEs) occurred from the same active region NOAA AR 12724. 5 Interestingly, the first two eruptions are associated with Type II radio bursts but the third is not. 6 Using the soft X-ray flux data, radio dynamic spect…

The hot limit of solar-like oscillations from Kepler photometry

Balona, Luis A.

Kepler short-cadence photometry of 2347 stars with effective temperatures in the range 6000 - 10000 K was used to search for the presence of solar-like oscillations. The aim is to establish the location of the hot end of the stochastic convective excitation mechanism and to what extent it may overlap the δ Scuti/γ Doradus instability region. A sim…