Results 31 to 40 of about 1,222 (137)

A Definitive Determination of the Interstellar Carbon Abundance toward ρ Ophiuchi A and B

open access: yesThe Astrophysical Journal Letters
We present the results of an effort to derive interstellar gas-phase C ii abundances along the lines of sight toward ρ  Oph A and B. Our analysis is based on high-resolution near-ultraviolet and far-ultraviolet archival spectra acquired with the Space ...
Adam M. Ritchey   +3 more
doaj   +1 more source

From Flybys to Sample Return: A Review of Space Probes and Robotic Sampling Technologies for Small Bodies

open access: yesJournal of Field Robotics, Volume 43, Issue 7, Page 4475-4514, October 2026.
ABSTRACT As a crucial puzzle piece of deep space exploration, exploring small bodies can provide significant scientific insights and valuable mineral resources. Unlike missions to the Moon and Mars, small‐body missions pose distinct technical challenges, including communication delays, weak gravity, and uncertain environments. This paper reviews a full
Xin Zhang   +3 more
wiley   +1 more source

Elastic Properties of Titan Tholins Revealed by Brillouin Spectroscopy

open access: yesJournal of Geophysical Research: Planets, Volume 131, Issue 10, October 2026.
Abstract Titan tholins, complex organic solids synthesized by simulating photochemical processes in Titan's atmosphere, are widely regarded as analogs to organic surface materials on the Saturnian moon. Their mechanical properties are critical for understanding the evolution of Titan's geomorphology and crustal layering.
Mark A. Johnson   +9 more
wiley   +1 more source

H i Kinematics and the E(B − V)/N(H i) Ratio

open access: yesThe Astrophysical Journal
The λ 21 cm H i emission that is used to trace the gas-to-dust ratio at high Galactic latitudes has contributions from material beyond the Milky Way disk, with uncertain and likely subsolar metallicity and dust content.
Harvey Liszt
doaj   +1 more source

Photochemical effects of Mars‐like UV irradiation on carboxylic acids in carbonaceous chondrites and expectations for abiotic background organics on Mars

open access: yesMeteoritics &Planetary Science, Volume 61, Issue 10, Page 2445-2465, October 2026.
Abstract In the search for life on Mars, understanding the origin of preserved organics is critical. Expected sources include exogenous delivery, endogenous synthesis, and potentially life. Environmental processing by ultraviolet (UV) irradiation can alter these organics, obscuring hallmarks of their origin. To deconvolve these effects, we conducted an
D. K. Buckner   +7 more
wiley   +1 more source

Thin‐film lithium niobate photonics: Frontiers in millimeter‐wave and terahertz generation and integrated applications

open access: yesInfoScience, Volume 3, Issue 3, September 2026.
With the advancement of 6G communications, high‐precision radar, and advanced imaging technologies, there is a growing demand for compact, high‐performance light sources capable of generating high‐frequency radio waves (millimeter‐wave and terahertz waves). This article systematically introduces how to efficiently generate these high‐frequency waves on
Jianfeng Xiong   +8 more
wiley   +1 more source

Towards a Measurement of the Primordial Helium Isotope Ratio

open access: yesThe 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   +6 more
doaj   +1 more source

A Solar Analog Model for Decrease in Far Ultraviolet Irradiance Under a Grand Minimum

open access: yesEarth and Space Science, Volume 13, Issue 9, September 2026.
Abstract Solar analog field stars having a range of magnetic activity can provide an estimate of solar spectral irradiance (SSI) variability relevant to understanding the Sun's influence on terrestrial climate. This approach is particularly useful for far ultraviolet (FUV) irradiance that cannot be observed from the Earth surface.
D. Lubin, C. Melis, D. Tytler
wiley   +1 more source

Spatially Resolved Comparison of SFRs from UV and Hα in GASP Gas-stripped Galaxies

open access: yesThe Astrophysical Journal
Star formation rates (SFRs) in galaxies offer a view of various physical processes across them, and are measured using various tracers, such as H α and ultraviolet (UV).
Neven Tomičić   +8 more
doaj   +1 more source

Absorption-line Observations of and CO in Sight Lines Toward the Vela and W28 Supernova Remnants

open access: yesThe Astrophysical Journal, 2023
Supernova remnants act as particle accelerators, providing the cosmic-ray protons that permeate the interstellar medium and initiate the ion–molecule reactions that drive interstellar chemistry. Enhanced fluxes of cosmic-ray protons in close proximity to
Nick Indriolo
doaj   +1 more source

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