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Related papers: Primary neutral helium in the heliosphere

200 papers

During the solar journey through galactic space, variations in the physical properties of the surrounding interstellar medium (ISM) modify the heliosphere and modulate the flux of galactic cosmic rays (GCR) at the surface of the Earth, with…

Astrophysics of Galaxies · Physics 2015-05-20 Priscilla C. Frisch , Hans-Reinhard Mueller

We carried out synthetic observations of interstellar atomic hydrogen at 21cm wavelength by utilizing the magneto-hydrodynamical numerical simulations of the inhomogeneous turbulent interstellar medium (ISM) Inoue and Inutsuka (2012). The…

SPHEREx, a recently launched astronomy mission, detected a bright 1.083 micron emission feature in the commissioning data. The PI group attributed this feature to the He I 1.0833 micron triplet line. Here, I review the physics and aeronomy…

Earth and Planetary Astrophysics · Physics 2025-09-19 S. R. Kulkarni

Over the course of its motion through the Galaxy, our solar system has encountered many interstellar environments of varying characteristics. Interstellar medium (ISM) density variations spanning seven orders of magnitude are commonly seen…

Solar and Stellar Astrophysics · Physics 2015-06-16 Katherine Wyman , Seth Redfield

Stellar and nebular abundance indicators reveal that there exists significant abundance fluctuations in the interstellar medium (ISM) of gas-rich galaxies. It is shown that at the present observed solar level of O/H $\sim 6 \times 10^{-4}$,…

Astrophysics · Physics 2007-05-23 Jean-Rene ROY , Daniel KUNTH

Gas-phase hydroxylamine (NH$_2$OH) has recently been detected within dense clouds in the interstellar medium. However, it is also likely present within interstellar ices, as well as on the icy surfaces of outer Solar System bodies, where it…

Transit observations in the helium triplet around 10830 Angstrom are a successful tool to study exoplanetary atmospheres and their mass loss. Forming those lines requires ionisation and recombination of helium in the exoplanetary…

Earth and Planetary Astrophysics · Physics 2022-03-14 K. Poppenhaeger

We combine observations of spiral galaxies in the [CII] line at 158 micron, made with the Long Wavelength Spectrometer aboard ISO, with previous data from the Kuiper Airborne Observatory to study the origin of this line, which is the main…

Astrophysics · Physics 2009-11-06 D. Pierini , J. Lequeux , A. Boselli , K. J. Leech , H. J. Voelk

Molecular oxygen has been the subject of many observational searches as chemical models predicted it to be a reservoir of oxygen. Although it has been detected in two regions of the interstellar medium, its rarity is a challenge for…

Astrophysics of Galaxies · Physics 2019-06-04 V. Wakelam , M. Ruaud , P. Gratier , I. A. Bonnell

The charge exchange between the interstellar medium (ISM) and the solar wind plasma is crucial for determining the structures of the heliosphere. Since both the neutral-ion and neutral-neutral collision mean free paths are either comparable…

Space Physics · Physics 2024-03-20 Yuxi Chen , Gabor Toth , Erick Powell , Talha Arshad , Ethan Bair , Marc Kornbleuth , Merav Opher

Recent James Webb Space Telescope observations of cool, rocky exoplanets reveal a probable lack of thick atmospheres, suggesting prevalent escape of the secondary atmospheres formed after losing primordial hydrogen. Yet, simulations…

Earth and Planetary Astrophysics · Physics 2026-02-19 Richard D. Chatterjee , Raymond T. Pierrehumbert

Since in situ studies and interplanetary dust collections only provide a spatially limited amount of information about the interplanetary dust properties, it is of major importance to complete these studies with properties inferred from…

Earth and Planetary Astrophysics · Physics 2016-09-20 Jeremie Lasue , Anny-Chantal Levasseur-Regourd , Nicolas Fray , Hervé Cottin

The low density interstellar medium (ISM) close to the Sun and inside of the heliosphere provides a unique laboratory for studying interstellar dust grains. Grain characteristics in the nearby ISM are obtained from observations of…

Astrophysics of Galaxies · Physics 2015-06-05 Priscilla C. Frisch , Jonathan D. Slavin

We construct partially ionized hydrogen atmosphere models for magnetized neutron stars in radiative equilibrium with fixed surface fields between B=10^12 and 2x10^13 G and effective temperatures logT_eff=5.5-6.8, as well as with surface B…

Astrophysics · Physics 2009-06-23 Wynn C. G. Ho , Alexander Y. Potekhin , Gilles Chabrier

We compare observations of HI from the Very Large Array (VLA) and the Arecibo Observatory and observations of HCO$^+$ from the Atacama Large Millimeter/submillimeter Array (ALMA) and the Northern Extended Millimeter Array (NOEMA) in the…

We report detection of the 609u line of neutral atomic carbon in globules of the Helix nebula. The measurements were made towards the position of peak CO emission. At the same position, we obtained high-quality CO(2-1) and 13CO(2-1) spectra…

Astrophysics · Physics 2009-10-30 K. Young , P. Cox , P. J. Huggins , T. Forveille , R. Bachiller

We describe the interface between the outer heliosphere and the local interstellar medium (LISM) surrounding the Sun. The components of the inner LISM are the four partially ionized clouds [the Local Interstellar Cloud (LIC), G cloud, Blue…

Solar and Stellar Astrophysics · Physics 2020-01-08 Jeffrey L. Linsky , Seth Redfield , Dennis Tilipman

We describe an approach to detecting ionizing radiation that combines the special properties of superfluid helium with the sensitivity of quantum optics techniques. Ionization in liquid helium results in the copious production of metastable…

Nuclear Experiment · Physics 2009-11-11 D. N. McKinsey , W. H. Lippincott , J. Nikkel , W. Rellergert

Ionized carbon is the main gas-phase reservoir of carbon in the neutral diffuse interstellar medium and its 158 micron fine structure transition [CII] is the most important cooling line of the diffuse interstellar medium (ISM). We combine…