Search Publications
Stringent Constraint on Galactic Positron Production
Beacom, John F.; Yüksel, Hasan
The intense 0.511 MeV gamma-ray line emission from the Galactic Center observed by INTEGRAL requires a large annihilation rate of nonrelativistic positrons. If these positrons are injected at even mildly relativistic energies, higher-energy gamma rays will also be produced. We calculate the gamma-ray spectrum due to inflight annihilation and compa…
Strategy for Searching for a Dark Matter Sterile Neutrino
Neronov, A.; Boyarsky, A.; Ruchayskiy, O. +2 more
We propose a strategy for how to look for dark matter particles possessing a radiative decay channel and derive constraints on their parameters from observations of x rays from our own Galaxy and its dwarf satellites. When applied to sterile neutrinos in the keV mass range this approach gives a significant improvement to restrictions on neutrino p…
Anisotropic Turbulent Spectra in the Terrestrial Magnetosheath as Seen by the Cluster Spacecraft
Balogh, A.; Belmont, G.; Sahraoui, F. +3 more
Here we report the first three-dimensional spatial spectrum of the low frequency magnetic turbulence obtained from the four Cluster spacecraft in the terrestrial magnetosheath close to the magnetopause. We show that the turbulence is compressible and dominated by mirror structures, its energy is injected at a large scale kρ∼0.3 (l∼2000 km) via a m…
Formation of Inner Structure of a Reconnection Separatrix Region
Nilsson, H.; André, M.; Vaivads, A. +3 more
We present multipoint spacecraft observations at the dayside magnetopause of a magnetic reconnection separatrix region. This region separates two plasmas with significantly different temperatures and densities, at a large distance from the X line. We identify which terms in the generalized Ohm’s law balance the observed electric field throughout t…
Wave-Number Spectra and Intermittency in the Terrestrial Foreshock Region
Glassmeier, K. -H.; Narita, Y.; Treumann, R. A.
Wave-number spectra of magnetic field fluctuations are directly determined in the terrestrial foreshock region (upstream of a quasiparallel collisionless shock wave) using four-point Cluster spacecraft measurements. The spectral curve is characterized by three ranges reminiscent of turbulence: energy injection, inertial, and dissipation range. The…