Results 31 to 40 of about 665 (145)

OBSERVATIONAL CONSTRAINTS ON STELLAR FORMATION PROCESSES IN DUST-RICH GALACTIC REGIONS: PHYSICAL PARAMETERS, ENVIRONMENTAL CONDITIONS, AND ASTROPHYSICAL INTERPRETATION

open access: yes
Abstract Stellar formation in dust-rich galactic regions remains one of the central problems of contemporary astrophysics because it connects the evolution of interstellar matter, the structure of molecular clouds, the emergence of stellar populations, and the long-term chemical and dynamical development of galaxies.
Oleksandr Melnyk, Iryna Kovalenko
openaire   +2 more sources

The role of composition in the spectral evolution of carbonaceous asteroids as informed by Bennu sample return

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract Near‐Earth rubble‐pile asteroids Bennu and Ryugu are part of the carbonaceous taxonomic complex (C‐complex), and samples returned from both bodies resemble the most aqueously altered carbonaceous chondrites. However, telescopic and spacecraft visible–near infrared (VIS–NIR) reflectance spectra of Ryugu exhibit a red (positive) spectral slope ...
Ralph E. Milliken   +10 more
wiley   +1 more source

Adsorption of Volatiles on Dust Grains in Protoplanetary Disks

open access: yesThe Astrophysical Journal
The adsorption of volatile molecules onto dust grain surfaces fundamentally influences dust-related processes, including condensation of gas-phase molecules, dust coagulation, and planet formation in protoplanetary disks. Using advanced ab initio density
Lile Wang   +4 more
doaj   +1 more source

Mineralogy, mineral chemistry, and redox equilibria in ten aggregate particles from asteroid Bennu

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract Examination of 10 Bennu aggregate particles has revealed the presence of many phases which taken together can provide constraints on the oxygen fugacity (fO2) of Bennu samples. Phyllosilicates (saponite and serpentine), carbonates, oxides (magnetite, chromite), sulfides (pyrrhotite, pentlandite), phosphate (hydroxyapatite, Na‐Mg‐phosphate ...
K. Righter   +11 more
wiley   +1 more source

Evaluating maturity of organic matter in hydrated C1 and CM‐like clasts and a dehydrated clast within a polymict eucrite and a howardite

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract Volatile‐rich xenolithic clasts in different types of brecciated meteorites represent unique pristine solar system material. This study investigates the maturity and thermal history of organic matter using Raman spectroscopy and aqueous alteration effects using infrared spectroscopy in the matrix of 15 volatile‐rich clasts (C1 and CM‐like ...
Swarna Prava Das   +7 more
wiley   +1 more source

A Fast Second-order Solver for Stiff Multifluid Dust and Gas Hydrodynamics

open access: yesThe Astrophysical Journal Supplement Series
We present MDIRK: a multifluid second-order diagonally implicit Runge–Kutta method to study momentum transfer between gas and an arbitrary number ( N ) of dust species. The method integrates the equations of hydrodynamics with an implicit–explicit scheme
Leonardo Krapp   +3 more
doaj   +1 more source

Raman analysis of organic refractory materials after energetic processing: Evidence for amorphous carbon on TNOs and comets

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract Amorphous carbon (αC) is found in various extraterrestrial particles, including those thought to originate from the outer Solar System. αC can form through two main processes involving C‐rich materials: exposure to energetic charged particles and thermal processing.
M. Germanà   +10 more
wiley   +1 more source

Particle-in-cell Simulations of Plasma Oscillations Excited by Dust Impacts

open access: yesThe Astrophysical Journal
Dust-impact-induced plasma oscillations (dust ringing) detected in Saturn’s Enceladus plume provide a novel method for measuring electron density. However, since S. Ye et al. discovered such events, their underlying mechanisms remain unclear.
Han Wu   +7 more
doaj   +1 more source

Geometric Proca with matter in metric-Palatini gravity

open access: yesEuropean Physical Journal C: Particles and Fields, 2022
In the present work, we study linear, torsion-free metric-Palatini gravity, extended by the quadratics of the antisymmetric part of the Ricci tensor and extended also by the presence of the affine connection in the matter sector.
Durmuş Demir, Beyhan Puliçe
doaj   +1 more source

The Ames impact structure, Oklahoma: New radioisotopic constraints and implications for North American impact chronology

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract The Ames impact structure (Oklahoma) is thought to have formed during the Ordovician Meteor Event, based on conodont biostratigraphy of its crater fill. Here, U–Pb zircon dates from its impact‐melt portion, conducted using secondary ion mass spectrometry and laser ablation–inductively coupled plasma–mass spectrometry (n = 37 spots), yield a ...
Elizabeth J. Catlos   +9 more
wiley   +1 more source

Home - About - Disclaimer - Privacy