Results 61 to 70 of about 55,540 (200)

On the Fate of Little Red Dots

The 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, Lucas Zimmermann, Sebastián Valdebenito, Marcelo C. Vergara, Dominik R. G. Schleicher, Matías Liempi   +5 more
doaj   +1 more source

Image features of spinning regular black holes based on a locality principle

European Physical Journal C: Particles and Fields, 2021
To understand the true nature of black holes, fundamental theoretical developments should be linked all the way to observational features of black holes in their natural astrophysical environments. Here, we take several steps to establish such a link. We
Astrid Eichhorn, Aaron Held
doaj   +1 more source

Diagenetic and Hydrothermal Processes Produce Heavy Molybdenum Isotope Signatures in Pelagic Sediments of the North and South Pacific

Geochemistry, Geophysics, Geosystems, Volume 27, Issue 2, February 2026.
Abstract Molybdenum isotopes (δ98Mo) have been used for more than two decades to investigate past‐ocean redox conditions due to the distinct behavior of this element in oxic and anoxic environments. The oxic sink is generally accepted to have a near‐constant δ98Mo value of −0.7‰, a value derived primarily from the δ98Mo signatures of Fe–Mn crusts and ...
P. L. Fraga‐Ferreira, C. Siebert, M. Frank, F. Scholz   +3 more
wiley   +1 more source

Effects of Dissipation Physics on High-frequency Quasiperiodic Oscillations in Black Hole X-Ray Binaries

The Astrophysical Journal
We numerically investigate the effects of black hole spin and local dissipation profiles on high-frequency quasiperiodic oscillation (HFQPO) observed in black hole X-ray binaries (BHXBs).
Theodore Dezen, Sergio Gomez, Kathryn Anawalt   +2 more
doaj   +1 more source

Can accretion disk properties distinguish gravastars from black holes? [PDF]

, 2009
Gravastars, hypothetic astrophysical objects, consisting of a dark energy condensate surrounded by a strongly correlated thin shell of anisotropic matter, have been proposed as an alternative to the standard black hole picture of general relativity ...
Bhattacharyya S, Bilic N, Broderick A E, Broderick A E, Carter B M N, Cattoen C, Chapline G, Chirenti C B M H, Darmois G, DeBenedictis A, Falcke H, Finch M R, Francisco S N Lobo, Ghez A M, Gillessen S, Horvat D, Horvat D, Israel W, Liu J, Lobo F S N, Lobo F S N, Luminet J P, Mak M K, Novikov I D, Rocha P, Shafee R, Shakura N I, Tiberiu Harko, Tournear D, Visser M, Yuan Y F, Zoltán Kovács   +31 more
core   +2 more sources

Ionosphere‐Thermosphere Coupling in the Northern Polar Region During the May 2024 Geomagnetic Superstorm

Journal of Geophysical Research: Space Physics, Volume 131, Issue 2, February 2026.
Abstract The May 2024 superstorm, as the most intense geomagnetic storm since 2003, caused a variety of disturbances in the magnetosphere‐ionosphere‐thermosphere system. This study investigates the long‐lasting electron density depletion in the polar region and the underlying ionosphere‐thermosphere coupling, based on a comprehensive set of ...
Lei Cai, Anita Aikio, G. P. Geethakumari, Heikki Vanhamäki, I. I. Virtanen, Shin‐ichiro Oyama, Yongliang Zhang, Jiaojiao Zhang, Marc Hairston   +8 more
wiley   +1 more source

Hair of Astrophysical Black Holes [PDF]

, 2014
The "no hair" theorem is not applicable to black holes formed from collapse of a rotating neutron star. Rotating neutron stars can self-produce particles via vacuum breakdown forming a highly conducting plasma magnetosphere such that magnetic field lines are effectively "frozen-in" the star both before and during collapse.
openaire   +2 more sources

Observational implications of cosmologically coupled black holes

The Open Journal of Astrophysics, 2023
It was recently suggested that "cosmologically coupled" black holes with masses that increase in proportion to the volume of the Universe might constitute the physical basis of dark energy.
Sohan Ghodla, Richard Easther, M. M. Briel, J. J. Eldridge   +3 more
doaj   +1 more source

Obscuration of Crystalline Ca‐Sulfate in XRD and Raman Data When Coated by Amorphous Ferric Sulfate: Implications for the Amorphous Components at Gale Crater

Journal of Geophysical Research: Planets, Volume 131, Issue 2, February 2026.
Abstract Throughout Gale crater on Mars, the Curiosity rover has found high abundances (15–73 wt%) of X‐ray amorphous materials in the rocks and sediments. The composition of this amorphous fraction is primarily calculated by subtracting crystalline abundances measured by the Chemistry & Mineralogy X‐Ray Diffractometer (CheMin) from bulk elemental ...
R. J. Hopkins, A. D. Rogers, L. Ehm
wiley   +1 more source

New Estimates of the Spin and Accretion Rate of the Black Hole M87*

The Astrophysical Journal Letters
In this Letter, we use the imaging results of M87* from the Event Horizon Telescope (EHT) to calculate the rotational velocity of the inner edge of the accretion disk and find a value of ∼0.14 c .
Michael Drew, Joshua S. Stanway, Brett A. Patterson, Timothy J. Walton, Derek Ward-Thompson   +4 more
doaj   +1 more source