Results 61 to 70 of about 1,811,090 (221)

Mapping Our Path through the Local Interstellar Medium: High-resolution Ultraviolet Absorption Spectroscopy of Sight Lines along the Sun’s Historical Trajectory

The Astrophysical Journal
Using high-resolution UV data obtained from the Space Telescope Imaging Spectrograph on board the Hubble Space Telescope, we focus on eight sight lines along the Sun’s historical trajectory to reconstruct the morphology of our most recent interstellar ...
Hunter Vannier, Seth Redfield, Brian E. Wood, Hans-Reinhard Müller, Jeffrey L. Linsky, Priscilla C. Frisch   +5 more
doaj   +1 more source

Near‐Earth Cosmic Ray Modulation Index ϕ and Neutron Monitor Cutoff Rigidities at Hourly Cadence: Toward an Improved Monitoring of Solar‐Terrestrial Radiation Environment, Space Weather, and Space Climate

Journal of Geophysical Research: Space Physics, Volume 131, Issue 8, August 2026.
Abstract Cosmic rays (CRs) are energetic particles originating from galactic and extragalactic sources. When arriving into the solar system and the Sun's heliosphere, they are diverted and modulated by the magnetic activity of the Sun. This modulation can be quantified by the modulation parameter ϕ $\phi $ determined with the Force‐field approximation (
Pauli Väisänen, Nicholas Larsen, Sergey Koldobskiy, Markus Similä, David Pelosi, Miguel Orcinha   +5 more
wiley   +1 more source

Electronic Spectroscopy of C60+ and Its Analogs C60H2O+, C60H+, C60D+, and C60Mg+

The Astrophysical Journal
The fullerenes C _60 and C _70 have been detected in various interstellar environments, and the cation ${{{\rm{C}}}_{60}}^{+}$ has been identified as a carrier of at least four of the diffuse interstellar bands (DIBs). Based on the presence of fullerenes
Lisa Ganner, Gabriel Schöpfer, Alexander Ebenbichler, Stefan Bergmeister, Milan Ončák, Helgi Rafn Hrodmarsson, Elisabeth Gruber   +6 more
doaj   +1 more source

Spatial and temporal variations in interstellar absorption towards HD 72127AB [PDF]

, 2008
New optical spectra of Ca II and Na I towards HD 72127AB provide additional evidence for both spatial and temporal variations in the complex interstellar absorption along the two sightlines; archival ultraviolet spectra yield information on the ...
D. Welty, T. Simon, L. M. H. U. O. Chicago, U. N. Mexico, U. Chicago, Yerkes Obs.   +5 more
semanticscholar   +1 more source

Jovian Auroral Proton Precipitation

Journal of Geophysical Research: Space Physics, Volume 131, Issue 8, August 2026.
Abstract The total power of the Jovian aurora is about 1013–1014 W with ultraviolet emission observed in the Lyman and Werner bands of molecular hydrogen. X‐ray, radio, and infrared emissions have also been observed. The Jovian Auroral Distributions Experiment and the Jovian Energetic Particle Detector Instrument onboard the Juno spacecraft, orbiting ...
S. J. Houston, T. E. Cravens, O. Q. Hamil, J. H. Waite, D. R. Schultz   +4 more
wiley   +1 more source

Towards a Measurement of the Primordial Helium Isotope Ratio

The Astrophysical Journal
We report the discovery of two metastable neutral helium (He I *) absorbers in the Milky Way, and use the upgraded CRyogenic InfraRed Echelle Spectrograph (or CRIRES) on the Very Large Telescope to determine the helium isotope ratio, ^3 He/ ^4 He, along ...
Ryan J. Cooke, James W. Johnson, Pasquier Noterdaeme, Max Pettini, Louise Welsh, Aldric Wong, Céline Péroux   +6 more
doaj   +1 more source

Observations of interstellar Lyman-α absorption [PDF]

Symposium - International Astronomical Union, 1970
Absorption at the Lyman-α transition from interstellar neutral hydrogen has been observed in the ultraviolet spectra of 18 nearby O and B stars. Radiation damping is the dominant cause of line broadening, which makes the derived line-of-sight column densities proportional to the square of the observed equivalent widths.
openaire   +1 more source

Engineering of Crystallinity to Amplify Chiroptical Activity of TiO2 Nanohelices for Enhancing Dissymmetric Circularly Polarized Photocatalysis

Advanced Functional Materials, Volume 36, Issue 61, 30 July 2026.
Enhancing crystallinity through thermal annealing leads to amplifying the chiroptical activity of TiO2 nanohelices (NHs) fabricated by glancing angle deposition, ascribed to the suppression of charge trapping. The enhanced chiroptical activity can be converted into pronounced dissymmetric photocatalytic kinetics of circularly polarized photocatalysis ...
Ying Wang, Lin Yang, Junjun Liu, Zhifeng Huang   +3 more
wiley   +1 more source

Tiny-scale Properties within the Interstellar Medium toward PSR J1644−4559. I. Observational Evidence of Turbulence-induced Tiny-scale Atomic Structures

The Astrophysical Journal Supplement Series
We investigated H i absorption toward a single pulsar, PSR J1644−4559, and its variability over timescales from days to years, using Murriyang, CSIRO’s Parkes Radio Telescope.
Mengting Liu, Di Li, J. R. Dawson, Joel M. Weisberg, Snežana Stanimirović, George Hobbs, Simon Johnston, Lawrence Toomey, Siyao Xu, Chao-Wei Tsai, Donghui Quan, Stacy Mader, James A. Green, Lei Zhang, Ningyu Tang, Pei Wang, Kai Zhang, Pei Zuo, Gan Luo, Yi Feng, Shi Dai, Aditi Kaushik, Mengyao Xue, Chenchen Miao   +23 more
doaj   +1 more source

Deterministic Propagation of Suprathermal Ions Through the Heliosphere

Journal of Geophysical Research: Space Physics, Volume 131, Issue 7, July 2026.
Abstract The PEPSSI instrument onboard New Horizons is sampling the energy range that bridges pickup and suprathermal He+ ${\mathrm{H}\mathrm{e}}^{+}$ ions for the first time in the outer heliosphere. New Horizons repeatedly encountered structures beyond 30 au that we interpret as the spiral of a corotating interaction region (CIR) for an extended ...
P. Kollmann, E. C. Roelof, M. E. Hill, R. B. Decker, P. Brandt, R. L. McNutt Jr., P. S. Mostafavi, R. Nikoukar, J. W. Parker, K. N. Singer, J. Spencer, A. Stern, A. J. Verbiscer   +12 more
wiley   +1 more source