Results 21 to 30 of about 983 (58)

Leptonic dark matter annihilation in the evolving universe: constraints and implications [PDF]

open access: yes, 2009
The cosmic electron and positron excesses have been explained as possible dark matter (DM) annihilation products. In this work we investigate the possible effects of such a DM annihilation scenario during the evolution history of the Universe.
Q. Yuan   +13 more
semanticscholar   +1 more source

Euclid: Validation of the MontePython forecasting tools [PDF]

open access: yesAstronomy & Astrophysics, 2023
The mission of the European Space Agency will perform a survey of weak lensing cosmic shear and galaxy clustering in order to constrain cosmological models and fundamental physics.
S. Casas   +454 more
semanticscholar   +1 more source

Giant Pulses from PSR B1937+21 with Widths ≤ 15 Nanoseconds and Tb ⩾ 5 × 1039 K, the Highest Brightness Temperature Observed in the Universe [PDF]

open access: yes, 2004
Giant radio pulses of the millisecond pulsar B1937+21 were recorded with the S2 VLBI system at 1.65 GHz with NASA/JPL's 70 m radio telescope at Tidbinbilla, Australia.
V. Soglasnov   +10 more
semanticscholar   +1 more source

High-spectral-resolution Observations of the Optical Filamentary Nebula Surrounding NGC 1275 [PDF]

open access: yesAstrophysical Journal, 2023
We present new high-spectral-resolution observations (R = λ/Δλ = 7000) of the filamentary nebula surrounding NGC 1275, the central galaxy of the Perseus cluster.
B. Vigneron   +39 more
semanticscholar   +1 more source

X-Ray Lighthouses of the High-Redshift Universe: Probing the Most Luminous z > 4 Palomar Digital Sky Survey Quasars with Chandra [PDF]

open access: yes, 2002
We present the results from exploratory Chandra observations of nine high-redshift (z = 4.09–4.51) optically selected quasars. These quasars, taken from the Palomar Digital Sky Survey (DPOSS), are among the optically brightest and most luminous z > 4 ...
C. Vignali   +12 more
semanticscholar   +1 more source

Astrophysical tests of gravity: a screening map of the nearby universe [PDF]

open access: yes, 2012
Astrophysical tests of modified gravity theories in the nearby universe have been emphasized recently by Hui 2009 and Jain 2011. A key element of such tests is the screening mechanism whereby general relativity is restored in massive halos or high ...
Anna Cabr'e   +14 more
semanticscholar   +1 more source

The Long-Term Evolution of the Atmosphere of Venus: Processes and Feedback Mechanisms [PDF]

open access: yesSpace Science Reviews, 2022
This work reviews the long-term evolution of the atmosphere of Venus, and modulation of its composition by interior/exterior cycling. The formation and evolution of Venus’s atmosphere, leading to contemporary surface conditions, remain hotly debated ...
C. Gillmann   +70 more
semanticscholar   +1 more source

VERY HIGH ENERGY γ-RAYS FROM THE UNIVERSE’S MIDDLE AGE: DETECTION OF THE z = 0.940 BLAZAR PKS 1441+25 WITH MAGIC [PDF]

open access: yes, 2015
The flat-spectrum radio quasar PKS 1441+25 at a redshift of z = 0.940 is detected between 40 and 250 GeV with a significance of 25.5σ using the MAGIC telescopes.
M. L. Ahnen   +484 more
semanticscholar   +1 more source

Luminous Infrared Galaxies in the Local Universe [PDF]

open access: yes, 2006
We study the morphology and star formation properties of 159 local luminous infrared galaxies (LIRGs) using multicolor images from Data Release 2 (DR2) of the Sloan Digital Sky Survey (SDSS).
J. Wang   +9 more
semanticscholar   +1 more source

Euclid. I. Overview of the Euclid mission [PDF]

open access: yesAstronomy & Astrophysics
The current standard model of cosmology successfully describes a variety of measurements, but the nature of its main ingredients, dark matter and dark energy, remains unknown.
Euclid Collaboration Y. Mellier   +499 more
semanticscholar   +1 more source

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