Search Publications
Entropy conservation and rate of propagation of bubbles in the Earth's magnetotail: A case study
Wing, Simon; Sanchez, Ennio R.; Spanswick, Emma +1 more
Earthward propagation of low-density flux tubes, called “plasma bubbles,” is a candidate mechanism to reduce total entropy in the plasma sheet. MHD models predict that bubbles conserve total entropy (S) as they propagate earthward, that the amount of density depletion governs the speed of propagation, and that bubbles slow down as their S nears th…
Deprojected analysis of Abell 1835 observed with Chandra and compared with XMM-Newton
Chen, Y.; Li, C. K.; Jia, S. M. +3 more
Using a deprojection technique, we study the X-ray properties of the galaxy cluster Abell 1835 observed with Chandra, including temperature, abundance, electron density, gas mass fraction, and total mass. A comparison with the results without deprojection shows that the properties do not change much. When we compare the results with those of XMM-N…
Vlasov simulation of electrostatic solitary structures in multi-component plasmas
Goldstein, Melvyn L.; Umeda, Takayuki; Pickett, Jolene S. +1 more
Electrostatic solitary structures have been observed in the Earth's magnetosheath by the Cluster spacecraft. Recent theoretical work has suggested that these solitary structures are modeled by electron acoustic solitary waves existing in a four-component plasma system consisting of core electrons, two counter-streaming electron beams, and one spec…
Test-field for evaluation of laboratory craters using a Crater Shape-based interpolation crater detection algorithm and comparison with Martian and Lunar impact craters
Lončarić, Sven; Vinković, Dejan; Salamunićcar, Goran +5 more
Impact craters are some of the most abundant geological features on most lunar and planetary bodies, providing insight into the history and physical processes that shaped their surface. It is therefore not surprising that extensive research has been done in the past on laboratory craters, as well as on crater detection algorithms (CDAs). No prior …
Large Field-of-View Spectropolarimetric Observations with a Large Aperture Telescope
Aulanier, G.; Molodij, G.
In the context of the increasing interest in large-aperture telescopes dedicated to the Sun, we present a study to evaluate the adaptive-optics system limitations on the requirements expected for magnetic-field extrapolations and data-driven MHD simulations of active regions. The questions we address include: What is the size of the field of view …
Constraining the Optical Emission from the Double Pulsar System J0737-3039
Dalessandro, E.; Camilo, F.; Pellizzoni, A. +10 more
We present the first optical observations of the unique system J0737-3039 (composed of two pulsars, hereafter PSR-A and PSR-B). Ultra-deep optical observations, performed with the High Resolution Camera of the Advanced Camera for Surveys on board the Hubble Space Telescope, could not detect any optical emission from the system down to m F435W…
Properties of dust at the Galactic center probed by AKARI far-infrared spectral mapping. Detection of a dust feature
Takahashi, H.; Nakagawa, T.; Okada, Y. +5 more
Aims: We investigate the properties of interstellar dust in the Galactic center region toward the Arches and Quintuplet clusters.
Methods: With the Fourier Transform Spectrometer of the AKARI/Far-Infrared Surveyor, we performed the far-infrared (60-140 cm-1) spectral mapping of an area of about 10' × 10' that includes both clu…
Current sheet oscillations in the magnetic filament approach
Semenov, V. S.; Erkaev, N. V.; Biernat, H. K.
Magnetic filament approach is applied for modeling of nonlinear "kink"-like flapping oscillations of thin magnetic flux tubes in the Earth's magnetotail current sheet. A discrete approximation for the magnetic flux tube was derived on a basis of the Hamiltonian formulation of the problem. The obtained system of ordinary differential equations was …
Remote estimation of reconnection parameters in the Earth's magnetotail: model and observations
Glassmeier, K. -H.; Kubyshkin, I. V.; Nakamura, R. +8 more
We develop a method to estimate the reconnected magnetic flux and the location of the reconnection site using properties of magnetic field and plasma velocity disturbances in the regions surrounding the reconnection plasma flow. Our analysis is based on a 3-D non-steady reconnection model with a finite-sized X-line length. In this framework, we ob…
The area asymmetry in bipolar magnetic fields
Yamamoto, T. T.
Context. The area asymmetry between the preceding and following regions of opposite magnetic polarity in a bipolar sunspot group has been known since the studies of Hale and his colleagues in the early 20th century. This area asymmetry, however, has not yet been investigated quantitatively using magnetograms.
Aims: We quantitatively define th…