Results 11 to 20 of about 983 (58)

The universal shape of the X-ray variability power spectrum of AGN up to z~3 [PDF]

open access: yesAstronomy & Astrophysics, 2023
We study the ensemble X-ray variability properties of Active Galactic Nuclei (AGN) over a large range of timescales (20 ks $\leq T\leq$ 14 yrs), redshift ($0\leq z \lesssim 3$), luminosities ($10^{40}$ erg s$^{-1}\leq L_X\leq 10^{46}$ erg s$^{-1}$) and ...
M. Paolillo   +66 more
semanticscholar   +1 more source

Completeness of the NASA/IPAC Extragalactic Database (NED) Local Volume Sample [PDF]

open access: yesAstrophysical Journal Supplement Series, 2023
We introduce the NASA/IPAC Extragalactic Database (NED) Local Volume Sample (NED-LVS), a subset of ∼1.9 million objects with distances out to 1000 Mpc.
D. Cook   +24 more
semanticscholar   +1 more source

Transient RFI environment of LOFAR-LBA at 72-75 MHz. Impact on ultra-widefield AARTFAAC Cosmic Explorer observations of the redshifted 21-cm signal [PDF]

open access: yesAstronomy & Astrophysics, 2023
Measurement of the redshifted 21-cm signal of neutral hydrogen from the Cosmic Dawn (CD) and Epoch of Reionisation (EoR) promises to unveil a wealth of information about the astrophysical processes during the first billion years of evolution of the ...
B. Gehlot   +30 more
semanticscholar   +1 more source

Euclid preparation. XXIX. Water ice in spacecraft. I. The physics of ice formation and contamination [PDF]

open access: yesAstronomy & Astrophysics, 2023
Molecular contamination is a well-known problem in space flight. Water is the most common contaminant and alters numerous properties of a cryogenic optical system. Too much ice means that Euclid's calibration requirements and science goals cannot be met.
Euclid Collaboration M. Schirmer   +499 more
semanticscholar   +1 more source

X-Ray Detection of the Galaxy’s Missing Baryons in the Circumgalactic Medium of L* Galaxies [PDF]

open access: yesAstrophysical Journal Letters, 2023
The number of baryons hosted in the disks of galaxies is lower than expected based on the mass of their dark matter halos and the fraction of baryon-to-total matter in the Universe, giving rise to the so-called galaxy missing-baryon problem. The presence
F. Nicastro   +42 more
semanticscholar   +1 more source

DARWIN – a next-generation liquid xenon observatory for dark matter and neutrino physics [PDF]

open access: yesInternational Conference on Rebooting Computing, 2021
The nature of dark matter and properties of neutrinos are among the most pressing issues in contemporary particle physics. The dual-phase xenon time-projection chamber is the leading technology to cover the available parameter space for weakly ...
J. Aalbers   +499 more
semanticscholar   +1 more source

The New Scenario of the Initial Evolution of the Universe [PDF]

open access: yes, 1996
We propose that the Universe created from ”nothing” with relatively small particles number and quickly relaxed to quasiequilibrium state at the Planck parameters. The classic cosmological solution for this Universe with Λ-term has two branches divided by
V.Burdyuzha   +4 more
semanticscholar   +1 more source

The high energy X-ray probe (HEX-P): the most powerful jets through the lens of a superb X-ray eye [PDF]

open access: yesFrontiers in Astronomy and Space Sciences, 2023
A fraction of the active supermassive black holes at the centers of galaxies in our Universe are capable of launching extreme kiloparsec-long relativistic jets.
L. Marcotulli   +22 more
semanticscholar   +1 more source

Identifying the first generation of radio powerful AGN in the Universe with the SKA [PDF]

open access: yes, 2014
One of the most challenging and exciting subjects in modern astrophysics is that of galaxy formation at the epoch of reionisation. The SKA, with its revolutionary capabilities in terms of frequency range, resolution and sensitivity, will allow to explore
J. Afonso   +13 more
semanticscholar   +1 more source

Assessing the reliability of friends-of-friends groups on the future Javalambre Physics of the Accelerating Universe Astrophysical Survey [PDF]

open access: yes, 2013
Aims. We have performed a detailed analysis of the ability of the friends-of-friends algorithm to identify real galaxy systems in deep surveys such as the future Javalambre Physics of the Accelerating Universe Astrophysical Survey.
A. Zandivarez   +12 more
semanticscholar   +1 more source

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