Search Publications
Substorm Current Wedge Revisited
Lester, M.; Nakamura, R.; McPherron, R. L. +7 more
Almost 40 years ago the concept of the substorm current wedge was developed to explain the magnetic signatures observed on the ground and in geosynchronous orbit during substorm expansion. In the ensuing decades new observations, including radar and low-altitude spacecraft, MHD simulations, and theoretical considerations have tremendously advanced…
Origin and Evolution of the Cometary Reservoirs
Dones, Luke; Brasser, Ramon; Kaib, Nathan +1 more
Comets have three known reservoirs: the roughly spherical Oort Cloud (for long-period comets), the flattened Kuiper Belt (for ecliptic comets), and, surprisingly, the asteroid belt (for main-belt comets). Comets in the Oort Cloud were thought to have formed in the region of the giant planets and then placed in quasi-stable orbits at distances of t…
Cometary Isotopic Measurements
Jehin, Emmanuël; Engrand, Cécile; Sheridan, Simon +12 more
Isotopic ratios in comets provide keys for the understanding of the origin of cometary material, and the physical and chemical conditions in the early Solar Nebula. We review here measurements acquired on the D/H, 14N/15N, 16O/18O, 12C/13C, and 32S/34S ratios i…
The Composition of Comets
Mumma, Michael J.; Cochran, Anita L.; Schleicher, David G. +10 more
This paper is the result of the International Cometary Workshop, held in Toulouse, France in April 2014, where the participants came together to assess our knowledge of comets prior to the ESA Rosetta Mission. In this paper, we look at the composition of the gas and dust from the comae of comets. With the gas, we cover the various taxonomic studie…
Review on Current Sheets in CME Development: Theories and Observations
Reeves, Katharine K.; Lin, Jun; Raymond, John C. +5 more
We introduce how the catastrophe model for solar eruptions predicted the formation and development of the long current sheet (CS) and how the observations were used to recognize the CS at the place where the CS is presumably located. Then, we discuss the direct measurement of the CS region thickness by studying the brightness distribution of the C…
Current Sheets in the Earth Magnetotail: Plasma and Magnetic Field Structure with Cluster Project Observations
Nakamura, Rumi; Zelenyi, Lev; Artemyev, Anton +2 more
Thin current sheets having kinetic scales are an important plasma structure, where the magnetic energy dissipation and charged particle acceleration are the most effective. It is believed that such current sheets are self-consistently formed by the specific nonadiabatic dynamics of charged particles and play a critical role in many space plasma an…
Supernova Remnants Interacting with Molecular Clouds: X-Ray and Gamma-Ray Signatures
Slane, Patrick; Castro, Daniel; Ellison, Donald C. +2 more
The giant molecular clouds (MCs) found in the Milky Way and similar galaxies play a crucial role in the evolution of these systems. The supernova explosions that mark the death of massive stars in these regions often lead to interactions between the supernova remnants (SNRs) and the clouds. These interactions have a profound effect on our understa…
Large-Eddy Simulations of Magnetohydrodynamic Turbulence in Heliophysics and Astrophysics
Brandenburg, Axel; Velli, Marco; Toomre, Juri +9 more
We live in an age in which high-performance computing is transforming the way we do science. Previously intractable problems are now becoming accessible by means of increasingly realistic numerical simulations. One of the most enduring and most challenging of these problems is turbulence. Yet, despite these advances, the extreme parameter regimes …
The Earth: Plasma Sources, Losses, and Transport Processes
Liemohn, Michael W.; Fazakerley, Andrew; Wang, Chih-Ping +12 more
This paper reviews the state of knowledge concerning the source of magnetospheric plasma at Earth. Source of plasma, its acceleration and transport throughout the system, its consequences on system dynamics, and its loss are all discussed. Both observational and modeling advances since the last time this subject was covered in detail (Hultqvist et…
Magnetic Fields of Neutron Stars in X-Ray Binaries
Mereghetti, Sandro; Revnivtsev, Mikhail
A substantial fraction of the known neutron stars resides in X-ray binaries—systems in which one compact object accretes matter from a companion star. Neutron stars in X-ray binaries have magnetic fields among the highest found in the Universe, spanning at least the range from ∼108 to several 1013 G. The magnetospheres around…