Results 11 to 20 of about 112,066 (261)

Lyα visibility from z = 4.5 to 11 in the UDS field: Evidence for a high neutral hydrogen fraction and small ionized bubbles at z ∼ 7

open access: yesAstronomy & Astrophysics
The resonant scattering nature of Lyα photons interacting with neutral hydrogen makes Lyα emitters (LAEs) robust tracers of the intergalactic neutral hydrogen fraction, and thus sensitive probes of cosmic reionization.
Napolitano L.   +30 more
doaj   +1 more source

Detecting the signature of helium reionization through 3HeII 3.46 cm line-intensity mapping

open access: yesAstronomy & Astrophysics
Context. Helium reionization is the most recent phase change of the intergalactic medium, yet its timing and main drivers remain uncertain. Among the probes to trace to trace how it unfolds, the 3.46 cm hyperfine line of singly ionized helium has opened ...
Spina Benedetta   +6 more
doaj   +1 more source

Do multiple physiological OCT biomarkers indicate age-related decline in rod mitochondrial function in C57BL/6J mice?

open access: yesFrontiers in Neuroscience, 2023
PurposeTo test the hypothesis that rod photoreceptor mitochondria function in vivo progressively declines over time.Methods2, 12, and 24 month-old dark- and light-adapted C57BL/6J (B6J) mice were examined by OCT. We measured (i) an index of mitochondrial
Cole Goodman   +8 more
doaj   +1 more source

Effect of primordial black holes on the global 21 cm signal

open access: yesAstronomy & Astrophysics
The 21 cm global signal, a treasure trove of information about the nature of the first luminous sources of the Universe, has traditionally been modelled assuming that these early sources were predominantly star-forming galaxies.
Chatterjee Atrideb
doaj   +1 more source

Breaking through the cosmic fog: JWST/NIRSpec constraints on ionizing photon escape in reionization-era galaxies

open access: yesAstronomy & Astrophysics
Aims. The escape fraction of Lyman continuum photons (fesc(LyC)) is the last key unknown in our understanding of cosmic reionization. Directly estimating the escape fraction (fesc) of ionizing photons in the epoch of reionization (EoR) is impossible, due
Giovinazzo Emma   +17 more
doaj   +1 more source

Searching for the dark force with 21-cm spectrum in light of EDGES

open access: yesPhysics Letters B, 2019
The EDGES Collaboration has recently announced the detection of the 21-cm spectrum with an absorption profile centred at 78 megahertz, of which the depth is deeper than that expected by the standard cosmological paradigm. To enrich the heating process of
Chunlong Li, Yi-Fu Cai
doaj   +1 more source

The Dark Age of the Universe

open access: yesScience, 2003
The Dark Age is the period between the time when the cosmic microwave background was emitted and the time when the evolution of structure in the universe led to the gravitational collapse of objects, in which the first stars were formed. The period of reionization started with the ionizing light from the first stars, and it ended when all ...
openaire   +3 more sources

Euclid: Discovery of 31 new quasars at 6.6 < z < 7.8★

open access: yesAstronomy & Astrophysics
We report the discovery of 31 new high-z quasars in the redshift range 6.6 
Yang D.   +213 more
doaj   +1 more source

Les sites de hauteur en Crète pendant les siècles obscurs

open access: yesProjets de Paysage, 2010
At the end of the Bronze Age in Crete, a particular phenomenon makes its appearance. In effect, with the disappearing of centralized power and big palaces, the population scatters and leaves sites in lowland or along the coast to the advantage of site in
Nathalie Monio
doaj   +1 more source

Stratigraphy, Crater Size–Frequency Distribution, and Chronology of Selected Areas of Ganymede’s Light and Dark Terrains

open access: yesThe Planetary Science Journal, 2023
The stratigraphy of the largest natural satellite of our solar system, Ganymede, is investigated using available global mosaic (basemap) and high-resolution images. We are focusing on the reconstruction of the formation and tectonic evolution of selected
Namitha Rose Baby   +3 more
doaj   +1 more source

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