Results 101 to 110 of about 1,899,768 (248)

Discovery of Radial Spectral Hardening in the Hot Bubble of Planetary Nebula BD+30°3639 with Median Energy Imaging

The Astrophysical Journal
We apply an imaging analysis technique to study the spatial distribution of the X-ray spectral hardness across the hot bubble of planetary nebula BD+30°3639.
Rodolfo Montez Jr.
doaj   +1 more source

Microtextures and structures in metal–sulfide grains in NWA 869 meteorite and their relation to thermal history of L‐chondrite parent body

Meteoritics &Planetary Science, Volume 60, Issue 3, Page 616-631, March 2025.
Abstract Results of microanalysis study of NWA 869 meteorite, an ordinary chondrite, where silicates, Fe‐Ni alloys, and troilite are major constituents, are reported. The presented study of microtextures in metallic and sulfide grains provides information on processes occurring from the asteroid's accretion, through the impacts until cooling.
Paulina Skirak, Gabriela Opiła, Adam Piestrzyński, Gabriela Kozub‐Budzyń, Czesław Kapusta   +4 more
wiley   +1 more source

Is there ERE in bright nebulae? [PDF]

arXiv, 2000
In 1986 Witt & Schild studied the optical emission of selected bright nebulae. Comparison of the data to a model led the authors to conclude the nebulae have too high a level of I-band emission to be explained solely by the scattering of starlight. The excess is explained as a broad band I emission which originates in the nebulae.
arxiv  

On the X-ray temperature of hot gas in diffuse nebulae [PDF]

, 2018
X-ray emitting diffuse nebulae around hot stars are observed to have soft-band temperatures in the narrow range [1-3]$\times10^{6}$ K, independent of the stellar wind parameters and the evolutionary stage of the central star. We discuss the origin of this X-ray temperature for planetary nebulae (PNe), Wolf-Rayet nebulae (WR) and interstellar wind ...
arxiv   +1 more source

“Security, first of all, begins at home”: How Finland, Latvia, and Germany prepare “ordinary people” for crises

European Policy Analysis, Volume 11, Issue 1, Page 114-137, Winter 2025.
Abstract In Europe, and specifically in countries bordering the Baltic Sea, preparedness issues have moved up the policy agenda since Russia's 2014 and 2022 invasions of Ukraine. “Ordinary people” are encouraged to prepare for crises—be it through stockpiling food at home, fact‐checking information, or signing up for military training.
Alexandra M. Friede
wiley   +1 more source

Maser emission in planetary nebulae [PDF]

arXiv, 2008
Stars at the top of the asymptotic giant branch (AGB) can exhibit maser emission from molecules like SiO, H2O and OH. As the star evolves to the planetary nebula phase, mass-loss stops and ionization of the envelope begins, making the masers disappear progressively.
arxiv  

Petrofabrics in the CM chondrite Kolang: Evidence for non‐spherical chondrules in the protoplanetary disk

Meteoritics &Planetary Science, Volume 60, Issue 2, Page 190-205, February 2025.
Abstract The alignment of non‐spherical “flattened” chondrules into a petrofabric is a common feature of hydrated carbonaceous chondrite meteorites. This texture can form as a result of impacts at peak shock pressures exceeding 10 GPa. However, many carbonaceous chondrites with petrofabrics are unshocked.
Laura E. Jenkins, Martin R. Lee, Luke Daly, Ashley J. King, Cameron J. Floyd, Peter Chung, Sammy Griffin   +6 more
wiley   +1 more source

CM carbonaceous chondrite petrofabrics and their implications for understanding the relative chronologies of parent body deformation and aqueous alteration

Meteoritics &Planetary Science, Volume 60, Issue 2, Page 324-346, February 2025.
Abstract CM chondrites have been subjected to numerous alteration processes including brecciation and ductile deformation. Here, we present the results of 2D and 3D petrofabric analysis across a suite of meteorites: Aguas Zarcas, Cold Bokkeveld, Lewis Cliff (LEW) 85311, Murchison, and Winchcombe.
C. J. Floyd, L. E. Jenkins, P.‐E. Martin, L. Daly, M. R. Lee   +4 more
wiley   +1 more source

Detection of the Extended γ-Ray Emission around TeV Source 1LHAASO J0249+6022 with Fermi-LAT

The Astrophysical Journal
1LHAASO J0249+6022 is an extended very-high-energy γ -ray source discovered by the Large High-Altitude Air Shower Observatory. Based on nearly 16.1 yr of data from the Fermi Large Area Telescope, we report the probable γ -ray emission from 1LHAASO J0249 ...
Yunlu Gong, Liancheng Zhou, Qi Xia, Shan Chang, Jun Fang, Li Zhang   +5 more
doaj   +1 more source

Triple‐oxygen isotopes of stony micrometeorites by secondary ion mass spectrometry (SIMS): Olivine, basaltic glass and iron oxide matrix effects for sensitive high‐mass resolution ion microprobe‐stable isotope (SHRIMP‐SI)

Rapid Communications in Mass Spectrometry, Volume 39, Issue 1, 15 January 2025.
Rationale Micrometeorites are extraterrestrial particles smaller than ~2 mm in diameter, most of which melted during atmospheric entry and crystallised or quenched to form ‘cosmic spherules’. Their parentage among meteorite groups can be inferred from triple‐oxygen isotope compositions, for example, by secondary ion mass spectrometry (SIMS).
Seann J. McKibbin, Janaína N. Ávila, Trevor R. Ireland, Matthias Van Ginneken, Bastien Soens, Flore Van Maldeghem, Matthew Huber, Leonardo Baeza, Aditya Patkar, Frank Vanhaecke, Vinciane Debaille, Philippe Claeys, Steven Goderis   +12 more
wiley   +1 more source