Results 91 to 100 of about 300,825 (275)

Discovery of an [Fe/H] ∼ −4.8 Star in Gaia XP Spectra

The Astrophysical Journal Letters
We report on the discovery of GDR3_526285 (Gaia DR3 Source ID 5262850721755411072), a star with [Fe/H] = −4.82 ± 0.25 and one of the lowest metal (atomic number > 2) mass fractions ever found ( Z _GDR3 _ _526585  ≲ 1.0 × 10 ^−6 ).
Guilherme Limberg, Vinicius M. Placco, Alexander P. Ji, Yupeng Yao, Anirudh Chiti, Mohammad K. Mardini, Anna Frebel, Silvia Rossi   +7 more
doaj   +1 more source

Dwarf Galaxy Formation with and without Dark Matter–Baryon Streaming Velocities

The Astrophysical Journal, 2023
We study how supersonic streaming velocities of baryons relative to dark matter—a large-scale effect imprinted at recombination and coherent over ∼3 Mpc scales—affect the formation of dwarf galaxies at z ≳ 5.
Anna T. P. Schauer, Michael Boylan-Kolchin, Katelyn Colston, Omid Sameie, Volker Bromm, James S. Bullock, Andrew Wetzel   +6 more
doaj   +1 more source

Mapping the evolution of mitochondrial complex I through structural variation

FEBS Letters, EarlyView.
Respiratory complex I (CI) is crucial for bioenergetic metabolism in many prokaryotes and eukaryotes. It is composed of a conserved set of core subunits and additional accessory subunits that vary depending on the organism. Here, we categorize CI subunits from available structures to map the evolution of CI across eukaryotes. Respiratory complex I (CI)
Dong‐Woo Shin, Tingting Chen, James A. Letts   +2 more
wiley   +1 more source

SDSS J0018-0939: A Clear Signature of Sub-Chandrasekhar Mass Type 1a Supernova

The Astrophysical Journal
Very metal-poor (VMP) stars ([Fe/H] ≤ −2) that have subsolar values of [X/Fe] for α elements such as Mg, Si, and Ca, are referred to as α -poor VMP stars.
S. K. Jeena, Projjwal Banerjee
doaj   +1 more source

Can the James Webb Space Telescope detect isolated population III stars?

, 2011
Isolated population III stars are postulated to exist at approximately z=10-30 and may attain masses up to a few hundred solar masses. The James Webb Space telescope (JWST) is the next large space based infrared telescope and is scheduled for launch in ...
Rydberg, C. -E., Scott, P., Zackrisson, E.   +2 more
core   +1 more source

An intracellular transporter mitigates the CO2‐induced decline in iron content in Arabidopsis shoots

FEBS Letters, EarlyView.
This study identifies a gene encoding a transmembrane protein, MIC, which contributes to the reduction of shoot Fe content observed in plants under elevated CO2. MIC is a putative Fe transporter localized to the Golgi and endosomal compartments. Its post‐translational regulation in roots may represent a potential target for improving plant nutrition ...
Timothy Mozzanino, Meijie Li, Cécile Fizames, Mattia Adamo, Laurence Lejay, Christian Dubos, Matthieu Platre, Antoine Martin   +7 more
wiley   +1 more source

CRITICAL METALLICITY FOR POPULATION II STARS

Odessa Astronomical Publications, 2008
We present simple arguments about metallicity of transition from first stellar generation (population III) to the second one. We consider the efficiency of fragmentation in gas induced by thermal instability in cold gas layers and filaments (T < 104 K ...
E. O. Vasiliev, Yu. A. Shchekinov
doaj   +1 more source

Detectability of the First Cosmic Explosions

, 2013
We present a fully self-consistent simulation of a synthetic survey of the furthermost cosmic explosions. The appearance of the first generation of stars (Population III) in the Universe represents a critical point during cosmic evolution, signaling the ...
de Souza, R. S., Ishida, E. E. O., Johnson, J. L., Mesinger, A., Whalen, D. J.   +4 more
core   +1 more source

Cosmological consequences of Population III stars

The Astrophysical Journal, 1984
We examine the possible cosmological consequences of Population III stars. Their dark remnants could provide the ''missing mass.'' Their light could have produced either the entire 3 K background or observable distortions in its spectrum. Their heat or explosions could have reionized the universe and perhaps produced galaxies.
B. J. Carr, J. R. Bond, W. D. Arnett
openaire   +1 more source

By dawn or dusk—how circadian timing rewrites bacterial infection outcomes

FEBS Letters, EarlyView.
The circadian clock shapes immune function, yet its influence on infection outcomes is only beginning to be understood. This review highlights how circadian timing alters host responses to the bacterial pathogens Salmonella enterica, Listeria monocytogenes, and Streptococcus pneumoniae revealing that the effectiveness of immune defense depends not only
Devons Mo, Catherine S. Palmer, Jacqueline M. Kimmey   +2 more
wiley   +1 more source