Search Publications
The Hot, Accreted Halo of NGC 891
Bregman, Joel N.; Hodges-Kluck, Edmund J.; Li, Jiang-tao
Galaxies are surrounded by halos of hot gas whose mass and origin remain unknown. One of the most challenging properties to measure is the metallicity, which constrains both of these. We present a measurement of the metallicity around NGC 891, a nearby, edge-on, Milky Way analog. We find that the hot gas is dominated by low-metallicity gas near th…
The AMBRE Project: r-process elements in the Milky Way thin and thick discs
Recio-Blanco, A.; de Laverny, P.; Guiglion, G. +1 more
Context. The chemical evolution of neutron capture elements in the Milky Way disc is still a matter of debate. There is a lack of statistically significant catalogues of such element abundances, especially those of the r-process.
Aims: We aim to understand the chemical evolution of r-process elements in Milky Way disc. We focus on three pure …
Plasma Diagnostics of Coronal Dimming Events
Veronig, Astrid M.; Temmer, Manuela; Dissauer, Karin +1 more
Coronal mass ejections are often associated with coronal dimmings, i.e., transient dark regions that are most distinctly observed in Extreme Ultra-violet wavelengths. Using Atmospheric Imaging Assembly (AIA) data, we apply Differential Emission Measure diagnostics to study the plasma characteristics of six coronal dimming events. In the core dimmi…
The very faint X-ray binary IGR J17062-6143: a truncated disc, no pulsations, and a possible outflow
Altamirano, D.; Degenaar, N.; Wijnands, R. +10 more
We present a comprehensive X-ray study of the neutron star low-mass X-ray binary IGR J17062-6143, which has been accreting at low luminosities since its discovery in 2006. Analysing NuSTAR, XMM-Newton, and Swift observations, we investigate the very faint nature of this source through three approaches: modelling the relativistic reflection spectru…
Ion Escape From Mars Through Time: An Extrapolation of Atmospheric Loss Based on 10 Years of Mars Express Measurements
Barabash, Stas; Nilsson, Hans; Holmström, Mats +2 more
Solar wind-driven atmospheric ion escape has long been hypothesized as a major influence on the evolution of the Martian atmosphere due to the lack of a Martian global dipole magnetic field. We use 10 years (2007-2017) of Mars Express data to quantify the ion escape rate over the fully sampled parameter space of upstream solar wind dynamic pressur…
Multiwavelength observations of V407 Lupi (ASASSN-16kt) - a very fast nova erupting in an intermediate polar
Ness, J. -U.; Henze, M.; Kniazev, A. +19 more
We present a detailed study of the 2016 eruption of nova V407 Lupi (ASASSN-16kt), including optical, near-infrared, X-ray, and ultraviolet data from SALT, SMARTS, SOAR, Chandra, Swift, and XMM-Newton. Timing analysis of the multiwavelength light curves shows that, from 168 d post-eruption and for the duration of the X-ray supersoft source phase, t…
X-Ray and Optical Studies of the Redback System PSR J2129-0429
Ray, Paul S.; Kerr, Matthew; Hessels, Jason W. T. +6 more
PSR J2129-0429 is a 7.62 ms eclipsing millisecond pulsar (MSP) with a non-degenerate binary companion star that is likely in an early stage of the recycling process. It has one of the largest companion masses of a so-called “redback” (0.4 M ⊙) and has an unusually high surface magnetic field (1.6 × 109 G) for an MSP. We prese…
The co-existence of hot and cold gas in debris discs
Carmona, A.; Eiroa, C.; Montesinos, B. +19 more
Context. Debris discs have often been described as gas-poor discs as the gas-to-dust ratio is expected to be considerably lower than in primordial, protoplanetary discs. However, recent observations have confirmed the presence of a non-negligible amount of cold gas in the circumstellar (CS) debris discs around young main-sequence stars. This cold …
3D Anisotropy of Solar Wind Turbulence, Tubes, or Ribbons?
Grappin, Roland; Alexandrova, Olga; Verdini, Andrea +1 more
We study the anisotropy with respect to the local magnetic field of turbulent magnetic fluctuations at magnetofluid scales in the solar wind. Previous measurements in the fast solar wind obtained axisymmetric anisotropy, despite that the analysis method allows nonaxisymmetric structures. These results are probably contaminated by the wind expansio…
Magnetosheath jet properties and evolution as determined by a global hybrid-Vlasov simulation
Kajdič, Primož; Blanco-Cano, Xóchitl; Karlsson, Tomas +9 more
We use a global hybrid-Vlasov simulation for the magnetosphere, Vlasiator, to investigate magnetosheath high-speed jets. Unlike many other hybrid-kinetic simulations, Vlasiator includes an unscaled geomagnetic dipole, indicating that the simulation spatial and temporal dimensions can be given in SI units without scaling. Thus, for the first time, …