Results 41 to 50 of about 2,137,135 (205)

Primordial black holes in non-linear perturbation theory [PDF]

open access: yes, 2009
PhDThe thesis begins with a study of the origin of non-linear cosmological fluctuations. In particular, a class of models of multiple field inflation are considered, with specific reference to those cases in which the non-Gaussian correlation functions
Hidalgo-Cuellar, Juan Carlos
core   +4 more sources

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, EarlyView.
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

Quantum Aspects of Black Holes [PDF]

open access: yes, 2006
In this thesis we study two quantum aspects of black holes, their entropy and the Hawking effect. First, we present a model for the statistical interpretation of black hole entropy and show that this entropy emerges as a result of missing information ...
Deeg, Dorothea
core   +1 more source

Further Evidence for a Direct-collapse Origin of the Supermassive Black Hole at the Center of the ∞ Galaxy

open access: yesThe Astrophysical Journal Letters
The z = 1.14 ∞ galaxy consists of two ringed nuclei with an active supermassive black hole (SMBH) in between them. The system is likely the result of a nearly face-on collision between two disk galaxies with massive bulges. In P. van Dokkum et al.
Pieter van Dokkum   +4 more
doaj   +1 more source

Oxygen isotope thermometry and composition of aqueous fluids within the parent body of asteroid (101955) Bennu

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract We report on the petrography and oxygen isotopic compositions from in situ analyses of carbonates (Ca‐carbonate, dolomite, and Fe‐rich magnesite), magnetite, and apatite in particles from asteroid Bennu. Using oxygen isotope thermometry of Ca‐carbonate, dolomite, and magnetite, we estimated crystallization temperatures and the oxygen isotopic ...
Gary R. Huss   +12 more
wiley   +1 more source

A Microkrystite from the Australasian Tektite/Microtektite Strewn Field

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract Microkrystites are glassy impact spherules. They contain primary crystallites carrying information on the physical and chemical conditions prevailing during vaporization, melting, and ejection in large impact cratering events. We report on the geochemistry and mineralogy down to nanometer scale of the first microkrystite (ODP1144A,14) from the
Matteo Del Rio   +4 more
wiley   +1 more source

On the Fate of Little Red Dots

open access: yesThe Astrophysical Journal
We study the stability and possible fates of little red dots (LRDs) under the stellar-only interpretation of their observational features. This is performed by a combination of analyzing the relevant timescales in their stellar dynamics and also the ...
Andrés Escala   +5 more
doaj   +1 more source

The High Energy X-ray Probe (HEX-P): probing accretion onto stellar mass black holes

open access: yesFrontiers in Astronomy and Space Sciences
Accretion is a universal astrophysical process that plays a key role in cosmic history, from the epoch of reionization to galaxy and stellar formation and evolution. Accreting stellar-mass black holes in X-ray binaries are one of the best laboratories to
Riley M. T. Connors   +24 more
doaj   +1 more source

Approaching the Black Hole by Numerical Simulations

open access: yesUniverse, 2019
Black holes represent extreme conditions of physical laws. Predicted about a century ago, they are now accepted as astrophysical reality by most of the scientific community.
Christian Fendt
doaj   +1 more source

3D Architecture of Kodiak Butte as Evidence of Fluvial or Shoal‐Water Environments in Jezero Crater, Mars

open access: yesJournal of Geophysical Research: Planets, Volume 131, Issue 10, October 2026.
Abstract The Mars 2020 mission has explored depositional environments recorded in a fan‐shaped deposit on the western side of Jezero crater. Kodiak butte is an isolated outcrop of sedimentary rock ∼1 km south of the western fan scarp and may be an erosional remnant of said fan.
O. A. Kanine   +4 more
wiley   +1 more source

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