scholarly journals Orbital evolution of the inner solar system towards the red giant phase of the Sun: Simultaneous production of axions and neutrinos with a non-zero magnetic dipole moment

2019 ◽  
Vol 1160 ◽  
pp. 012007
Author(s):  
S Arceo Díaz ◽  
E E Bricio Barrios ◽  
K P Schröder ◽  
K Zuber ◽  
J A Verduzco Ramírez
Keyword(s):  
Dipole Moment ◽  
Solar System ◽  
Magnetic Dipole ◽  
Magnetic Dipole Moment ◽  
Orbital Evolution ◽  
The Sun ◽  
Simultaneous Production ◽  
Red Giant

Interaction of Titan's ionosphere with Saturn's magnetosphere

2008 ◽  
Vol 367 (1889) ◽  
pp. 773-788 ◽  
Author(s):  
Andrew J Coates
Keyword(s):  
Dipole Moment ◽  
Solar System ◽  
Magnetic Dipole ◽  
Magnetic Dipole Moment ◽  
Negative Ions ◽  
Low Energy ◽  
Energy Particle ◽  
Particle Detectors ◽  
Ion Escape ◽  
Ionization Processes

Titan is the only Moon in the Solar System with a significant permanent atmosphere. Within this nitrogen–methane atmosphere, an ionosphere forms. Titan has no significant magnetic dipole moment, and is usually located inside Saturn's magnetosphere. Atmospheric particles are ionized both by sunlight and by particles from Saturn's magnetosphere, mainly electrons, which reach the top of the atmosphere. So far, the Cassini spacecraft has made over 45 close flybys of Titan, allowing measurements in the ionosphere and the surrounding magnetosphere under different conditions. Here we review how Titan's ionosphere and Saturn's magnetosphere interact, using measurements from Cassini low-energy particle detectors. In particular, we discuss ionization processes and ionospheric photoelectrons, including their effect on ion escape from the ionosphere. We also discuss one of the unexpected discoveries in Titan's ionosphere, the existence of extremely heavy negative ions up to 10 000 amu at 950 km altitude.

scholarly journals Light(ly)-coupled dark matter in the keV range: freeze-in and constraints

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Jae Hyeok Chang ◽  
Rouven Essig ◽  
Annika Reinert
Keyword(s):  
Dark Matter ◽  
Dipole Moment ◽  
Magnetic Dipole ◽  
Magnetic Dipole Moment ◽  
Direct Detection ◽  
Gauge Coupling ◽  
Dark Photon ◽  
Red Giant ◽  
Bremsstrahlung Process ◽  
Relic Abundance

Abstract Dark matter produced from thermal freeze-out is typically restricted to have masses above roughly 1 MeV. However, if the couplings are small, the freeze-in mechanism allows for production of dark matter down to keV masses. We consider dark matter coupled to a dark photon that mixes with the photon and dark matter coupled to photons through an electric or magnetic dipole moment. We discuss contributions to the freeze-in production of such dark matter particles from standard model fermion-antifermion annihilation and plasmon decay. We also derive constraints on such dark matter from the cooling of red giant stars and horizontal branch stars, carefully evaluating the thermal processes as well as the bremsstrahlung process that dominates for masses above the plasma frequency. We find that the parameters needed to obtain the observed relic abundance from freeze-in are excluded below a few tens of keV, depending on the value of the dark gauge coupling constant for the dark photon portal model, and below a few keV, depending on the reheating temperature for dark matter with an electric or magnetic dipole moment. While laboratory probes are unlikely to probe these freeze-in scenarios in general, we show that for dark matter with an electric or magnetic dipole moment and for dark matter masses above the reheating temperature, the couplings needed for freeze-in to produce the observed relic abundance can be probed partially by upcoming direct-detection experiments.

scholarly journals Pseudospin versus magnetic dipole moment ordering in the isosceles triangular lattice material K3Er(VO4)2

2020 ◽  
Vol 102 (10) ◽  
Author(s):  
Danielle R. Yahne ◽  
Liurukara D. Sanjeewa ◽  
Athena S. Sefat ◽  
Bradley S. Stadelman ◽  
Joseph W. Kolis ◽  
...  
Keyword(s):  
Dipole Moment ◽  
Magnetic Dipole ◽  
Triangular Lattice ◽  
Magnetic Dipole Moment ◽  
Lattice Material

scholarly journals Stellar activity and magnetic shielding

2009 ◽  
Vol 5 (S264) ◽  
pp. 385-394 ◽  
Author(s):  
J.-M. Grießmeier ◽  
M. Khodachenko ◽  
H. Lammer ◽  
J. L. Grenfell ◽  
A. Stadelmann ◽  
...  
Keyword(s):  
Dipole Moment ◽  
Magnetic Dipole ◽  
Magnetic Dipole Moment ◽  
Direct Interaction ◽  
Planetary Atmosphere ◽  
Stellar Activity ◽  
Planetary Environment ◽  
Atmospheric Loss ◽  
Planetary Magnetic Field ◽  
Planetary Habitability

AbstractStellar activity has a particularly strong influence on planets at small orbital distances, such as close-in exoplanets. For such planets, we present two extreme cases of stellar variability, namely stellar coronal mass ejections and stellar wind, which both result in the planetary environment being variable on a timescale of billions of years. For both cases, direct interaction of the streaming plasma with the planetary atmosphere would entail servere consequences. In certain cases, however, the planetary atmosphere can be effectively shielded by a strong planetary magnetic field. The efficiency of this shielding is determined by the planetary magnetic dipole moment, which is difficult to constrain by either models or observations. We present different factors which influence the strength of the planetary magnetic dipole moment. Implications are discussed, including nonthermal atmospheric loss, atmospheric biomarkers, and planetary habitability.

Exotic-atom measurement of the magnetic dipole moment of theΣ−hyperon

1988 ◽  
Vol 37 (5) ◽  
pp. 1142-1152 ◽  
Author(s):  
D. W. Hertzog ◽  
M. Eckhause ◽  
P. P. Guss ◽  
D. Joyce ◽  
J. R. Kane ◽  
...  
Keyword(s):  
Dipole Moment ◽  
Magnetic Dipole ◽  
Magnetic Dipole Moment ◽  
Exotic Atom
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