Search Publications

Influence of the magnetic field on the density distribution of solar wind protons and cometary ions in the shock layer ahead of cometary ionospheres

Baranov, V. B.; Alexashov, D. B.

The "mass loading" of the solar wind by cometary ions produced by the photoionization of neutral molecules outflowing from the cometary nucleus plays a major role in the interaction of the solar wind with cometary atmospheres. In particular, this process leads to a decrease in the solar wind velocity with a transition from supersonic velocities to…

Cosmic sculpture: a new way to visualise the cosmic microwave background

Clements, D. L.; Sato, S.; Portela Fonseca, A.

3D printing presents an attractive alternative to visual representation of physical datasets such as astronomical images that can be used for research, outreach or teaching purposes, and is especially relevant to people with a visual disability. We here report the use of 3D printing technology to produce a representation of the all-sky cosmic micr…

Direct detection of gaps in Saturn's A ring

Esposito, Larry W.; Albers, Nicole; Brown, Zarah L. +1 more

Indirect observations spanning decades have indicated that Saturn's A ring is populated with a plethora of self-gravity wakes, small wavelike structures that arise from the gravitational attraction between ring particles. We present the direct detection of the gaps that represent the minima between the denser wakes. Through a statistical test, we …

Orbit of the mercury-manganese binary 41 Eridani

Hubrig, S.; Hummel, C. A.; Schöller, M. +1 more

Context. Mercury-manganese (HgMn) stars are a class of slowly rotating chemically peculiar main-sequence late B-type stars. More than two-thirds of the HgMn stars are known to belong to spectroscopic binaries.
Aims: By determining orbital solutions for binary HgMn stars, we will be able to obtain the masses for both components and the distanc…

Nonlinear evolution of 3D whistler waves in space plasmas

Sharma, R. P.; Pathak, Neha; Yadav, Nitin

The present model is proposed to study the nonlinear effects related to quasi-transverse 3D whistler waves in three different regions of space plasmas which are Earth's radiation belt, magnetopause, and solar wind plasma at 1 A.U. We have analysed the effect of considering the third dimension in the dynamics of whistler waves on Localization of wh…

X-Ray Temperatures, Luminosities, and Masses from XMM-Newton Follow-upof the First Shear-selected Galaxy Cluster Sample

Hughes, John P.; Wittman, David; Deshpande, Amruta J.

We continue the study of the first sample of shear-selected clusters from the initial 8.6 square degrees of the Deep Lens Survey (DLS); a sample with well-defined selection criteria corresponding to the highest ranked shear peaks in the survey area. We aim to characterize the weak lensing selection by examining the sample’s X-ray properties. There…

On the regularity of the covariance matrix of a discretized scalar field on the sphere

Barreiro, R. B.; Herranz, D.; Martínez-González, E. +2 more

We present a comprehensive study of the regularity of the covariance matrix of a discretized field on the sphere. In a particular situation, the rank of the matrix depends on the number of pixels, the number of spherical harmonics, the symmetries of the pixelization scheme and the presence of a mask. Taking into account the above mentioned compone…

Dawn-Dusk Asymmetries at the Terrestrial Magnetopause

Hasegawa, H.; Haaland, S. E.; Maes, L. +1 more

Investigation on M-class Flare-Associated Coronal Mass Ejections with and Without DH Type II Radio Bursts

Shanmugaraju, A.; Selvarani, G.; Lawrance, M. Bendict +1 more

We perform a statistical analysis on 157 M-class soft X-ray flares observed during 1997 - 2014 with and without deca-hectometric (DH) type II radio bursts aiming at the reasons for the non-occurrence of DH type II bursts in certain events. All the selected events are associated with halo Coronal Mass Ejections (CMEs) detected by the Solar and Heli…

Robust Cross-correlation-based Measurement of Clump Sizes in Galaxies

Glazebrook, Karl; Obreschkow, Danail; Abraham, Roberto G. +4 more

Stars form in molecular complexes that are visible as giant clouds (∼ {10}^5-6 {M}_⊙ ) in nearby galaxies and as giant clumps (∼ {10}^8-9 {M}_⊙ ) in galaxies at redshifts z≈ 1-3. Theoretical inferences on the origin and evolution of these complexes often require robust measurements of their characteristic si…