Results 41 to 50 of about 115,141 (206)

JWST Imaging of the Closest Globular Clusters—VI. The Lowest‐Mass Objects in M 4 and the Galactic Bulge

open access: yesAstronomische Nachrichten, EarlyView.
ABSTRACT We present James Webb Space Telescope observations of M 4—the closest globular cluster—that probe the lower Main Sequence down to the hydrogen‐burning limit. The unveiled stellar sequence reaches much fainter luminosities than previously possible, revealing a few extremely red objects that are consistent with brown dwarfs as cool as Teff∼1000K$
L. R. Bedin   +10 more
wiley   +1 more source

Effect of Background Magnetic Field on Ion Weibel Instability With High‐Intensity Short‐Pulse Lasers

open access: yesContributions to Plasma Physics, EarlyView.
ABSTRACT The effect of finite background magnetic field on magnetic field amplification by Weibel instability using high‐intensity short‐pulse lasers is investigated. We consider Weibel instability for counter‐streaming sub‐relativistic plasma flows generated by shooting pure carbon targets with short‐pulse lasers.
Taiki Jikei   +3 more
wiley   +1 more source

Using X‐ray computed microtomography (μCT) to determine subsample‐specific cosmogenic noble gas production rates of E (enstatite) chondrites

open access: yesMeteoritics &Planetary Science, Volume 60, Issue 3, Page 442-463, March 2025.
Abstract Cosmic ray exposure (CRE) ages provide information about the parent bodies and source regions of meteorite classes. Cosmogenic noble gases are often used to quantify exposure time scales ranging from tens of ka to hundreds of Ma. The production rate of cosmogenic noble gases is primarily controlled by a meteorite's chemical composition ...
M. Mijjum   +5 more
wiley   +1 more source

A case for radio galaxies as the sources of IceCube's astrophysical neutrino flux [PDF]

open access: yesJournal of Cosmology and Astroparticle Physics, 2016
15 pages, 4 ...
Dan Hooper, Dan Hooper
openaire   +4 more sources

A Small Pathbreaking Spacecraft: Giants of Space Research (Bernard Blake, Dieter Hovestadt, and Edward Stone)

open access: yesPerspectives of Earth and Space Scientists, Volume 6, Issue 1, December 2025.
Abstract The Solar, Anomalous, and Magnetospheric Explorer (SAMPEX) mission launched in July 1992 was the first NASA “Small Explorer” project. It had the goal to show how space missions could be developed much more rapidly than had become the situation in the 1980s and 1990s.
D. N. Baker, G. M. Mason
wiley   +1 more source

High Energy Neutrino Emission from Astrophysical Jets in the Galaxy [PDF]

open access: yesAdvances in High Energy Physics, 2015
We address simulated neutrino emission originated from astrophysical jets of compact objects within the Galaxy. These neutrinos are of high energies (Eνof the order up to a few TeV) and for their observation specialized instruments are in operation, both on Earth and in orbit.
Smponias, T., Kosmas, O.T.
openaire   +2 more sources

Tracing Ghost Cavities with Low Frequency Radio Observations [PDF]

open access: yes, 2006
We present X-ray and multi-frequency radio observations of the central radio sources in several X-ray cavity systems. We show that targeted radio observations are key to determining if the lobes are being actively fed by the central AGN.
A.C. Fabian   +14 more
core   +4 more sources

Proton Acceleration with Relativistic Electromagnetic Shock

open access: yesAdvanced Science, Volume 12, Issue 30, August 14, 2025.
New Ion Acceleration Mechanism! A novel cosmic‐ray proton acceleration mechanism is proposed, where relativistic electromagnetic shocks accelerate protons transversely. Hamiltonian analysis yields a scaling law linking the proton energy to the minimum longitudinal thickness of the shock.
Ting Xiao   +5 more
wiley   +1 more source

Mathematics and explanation in astronomy and astrophysics [PDF]

open access: yes, 2007
The purpose of this paper is to expound and clarify the mathematics and explanations commonly employed in certain notable areas of astronomy and astrophysics.
McCabe, Gordon
core   +2 more sources

Two Micron‐Size Dark Dimensions

open access: yesFortschritte der Physik, Volume 73, Issue 8, August 2025.
Abstract Two extra dimensions of micron scale might simultaneously address the gauge and cosmological hierarchy problems. In this paper various observational bounds in scenarios with one and two large extra dimensions are examined, to see if they are compatible with the micron scale.
Luis A. Anchordoqui   +2 more
wiley   +1 more source

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