Search Publications
Modelling the ArH+ emission from the Crab nebula
Barlow, M. J.; Viti, S.; Priestley, F. D.
We have performed combined photoionization and photodissociation region (PDR) modelling of a Crab nebula filament subjected to the synchrotron radiation from the central pulsar wind nebula, and to a high flux of charged particles; a greatly enhanced cosmic-ray ionization rate over the standard interstellar value, ζ0, is required to acco…
Search for aluminium monoxide in the winds of oxygen-rich AGB stars
Menten, K. M.; Olofsson, H.; Decin, L. +4 more
Context. Aluminium monoxide (AlO) is likely efficiently depleted from the gas around oxygen-rich evolved stars to form alumina (Al2O3) clusters and dust seeds. The presence of AlO gas in the extended atmospheres of evolved stars has been derived from optical spectroscopy. More recently, AlO gas was also detected at long wavel…
Cusp-shaped Structure of a Jet Observed By IRIS and SDO
Zhang, Jun; Zhang, Yuzong
On 2014 August 29, the trigger and evolution of a cusp-shaped jet were captured in detail at 1330 Å by the Interface Region Imaging Spectrograph. At first, two neighboring mini-prominences arose in turn from the low solar atmosphere and collided with a loop-like system over them. The collisions between the loop-like system and the mini-prominences…
The opposition effect of 67P/Churyumov-Gerasimenko on post-perihelion Rosetta images
Jorda, L.; Lamy, P. L.; Bertaux, J. -L. +45 more
High-resolution OSIRIS/Rosetta images of 67P/Churyumov-Gerasimenko acquired on the night run of 2016 April 9-10 show, at large scale, an opposition effect (OE) spot sweeping across Imhotep as the phase angle ranges from 0° to 17°. In this work, we fitted the phase curve of the whole surface imaged as well as three particular features using both th…
A study of halo and relic radio emission in merging clusters using the Murchison Widefield Array
Callingham, J. R.; Johnston-Hollitt, M.; Intema, H. T. +18 more
We have studied radio haloes and relics in nine merging galaxy clusters using the Murchison Widefield Array (MWA). The images used for this study were obtained from the GaLactic and Extragalactic All-sky MWA (GLEAM) Survey which was carried out at five frequencies, viz. 88, 118, 154, 188 and 215 MHz. We detect diffuse radio emission in eight of th…
Ion acoustic waves at comet 67P/Churyumov-Gerasimenko. Observations and computations
Gunell, H.; Altwegg, K.; Glassmeier, K. -H. +15 more
Context. On 20 January 2015 the Rosetta spacecraft was at a heliocentric distance of 2.5 AU, accompanying comet 67P/Churyumov-Gerasimenko on its journey toward the Sun. The Ion Composition Analyser (RPC-ICA), other instruments of the Rosetta Plasma Consortium, and the ROSINA instrument made observations relevant to the generation of plasma waves i…
Probing the Outflowing Multiphase Gas ∼1 kpc below the Galactic Center
Hernandez, Svea; Savage, Blair D.; Bland-Hawthorn, Joss +8 more
Comparison of interstellar medium (ISM) absorption in the UV spectrum of LS 4825, a B1 Ib-II star d = 21 ± 5 kpc from the Sun toward l = 1.°67 and b = -6.°63, with ISM absorption toward an aligned foreground star at d < 7.0 ± 1.7 kpc, allows us to isolate and study gas associated with the Milky Way nuclear wind. Spectra from the Space Telescope…
Three-dimensional Simulations and Spacecraft Observations of Sub-ion Scale Turbulence in the Solar Wind: Influence of Landau Damping
Passot, T.; Sahraoui, F.; Henri, P. +5 more
Three-dimensional nonlinear finite Larmor radius (FLR)-Landau fluid simulations, which include some small-scale ({k}\perp {ρ }I≳ 1) kinetic effects, are performed to explore the nature of the sub-ion scale turbulence in the solar wind and to investigate the role of Landau damping and FLR corrections. The resulting steady-stat…
Magnetohydrodynamic Simulations for Studying Solar Flare Trigger Mechanism
Kusano, K.; Shiota, D.; Inoue, S. +1 more
In order to understand the flare trigger mechanism, we conduct three-dimensional magnetohydrodynamic simulations using a coronal magnetic field model derived from data observed by the Hinode satellite. Several types of magnetic bipoles are imposed into the photospheric boundary of the Nonlinear Force-free Field model of Active Region (AR) NOAA 109…
Relieving tensions related to the lensing of the cosmic microwave background temperature power spectra
Couchot, F.; Henrot-Versillé, S.; Perdereau, O. +4 more
The angular power spectra of the cosmic microwave background (CMB) temperature anisotropies reconstructed from Planck data seem to present "too much" gravitational lensing distortion. This is quantified by the control parameter AL that should be compatible with unity for a standard cosmology. With the class Boltzmann solver and the prof…