Results 151 to 160 of about 21,650,361 (340)

Global Observations of Sporadic-E and Spread-F Occurrence Rates Using the COSMIC-2 Constellation

, 2023
We observed the presence of ionospheric L-band Sporadic-E and Spread-F occurrence during 2020-2022 using the Constellation Observing System for Meteorology, Ionosphere, and Climate – 2 (COSMIC-2) also known as FORMOSAT-7. We used the reported S4 scintillation index, an indicator of the scintillation along the line-of-sight, and following previous ...
openaire   +2 more sources

Redshift‐Agnostic Machine Learning Classification: Unveiling Peak Performance in Galaxy, Star, and Quasar Classification (Using SDSS DR17)

Astronomische Nachrichten, EarlyView.
ABSTRACT Classification of galaxies, stars, and quasars using spectral data is fundamental to astronomy, but often relies heavily on redshift. This study evaluates the performance of 10 machine learning algorithms on SDSS data to classify these objects, with a particular focus on scenarios where redshift information is unavailable.
Debashis Chatterjee, Prithwish Ghosh
wiley   +1 more source

Sidereal Variations in Cosmic Rays at 365 hg cm-2 [PDF]

, 1978
A. G. Fenton, K. B. Fenton, J. E. Humble
openalex   +1 more source

Exploring Dark Photon Production and Kinetic Mixing Constraints in Heavy‐Ion Collisions

Astronomische Nachrichten, EarlyView.
ABSTRACT Vector U‐bosons, often referred to as “dark photons,” are potential candidates for mediating dark matter interactions. In this study, we outline a procedure to derive theoretical constraints on the upper bound of the kinetic mixing parameter ϵ2MU$$ {\upvarepsilon}^2\left({M}_U\right) $$ using dilepton data from heavy‐ion from SIS to RHIC ...
Adrian William Romero Jorge, Elena Bratkovskaya, Taesoo Song, Laura Sagunski   +3 more
wiley   +1 more source

Cosmic Shear Analysis with CFHTLS Deep data

, 2005
We present the first cosmic shear measurements obtained from the T0001 release of the Canada-France-Hawaii Telescope Legacy Survey. The data set covers three uncorrelated patches (D1, D3 and D4) of one square degree each observed in u*, g', r', i' and z'
Bacon, Bacon, Bartelmann, Benabed, Benabed, Bernardeau, Bertin, Bolzonella, Boulade, Brodwin, Bruzual, Cooray, Crittenden, Crittenden, E. Semboloni, Erben, Fahlman, Fernández-Soto, H. Hoekstra, Heymans, Heymans, Hirata, Hirata, Hoekstra, Hoekstra, Hoekstra, I. Tereno, Jain, K. Benabed, Kaiser, King, L. C. Parker, L. Fu, L. van Waerbeke, Le Fèvre, Linder, Luppino, M. J. Hudson, McCracken, Mellier, Munshi, Munshi, Peacock, Pen, Perlmutter, R. Maoli, Riess, Riess, Réfrégier, S. D. J. Gwyn, Schneider, Schneider, Schneider, Smith, Spergel, Van Waerbeke, Van Waerbeke, Van Waerbeke, Van Waerbeke, Wittman, Y. Mellier   +60 more
core   +2 more sources

A Slowly Pulsating Run‐Away B Star at High Galactic Latitude Ejected From a Spiral Arm

Astronomische Nachrichten, EarlyView.
ABSTRACT We report the discovery of the young B6 V run‐away star LAMOST J083323.18 + 430825.4, 2.5 kpc above the Galactic plane. Its atmospheric parameters and chemical composition are determined from LAMOST spectra, indicating normal composition. Effective temperature (Teff$$ {T}_{\mathrm{eff}} $$ = 14,500$$ \mathrm{14,500} $$ K) and gravity (logg ...
Ulrich Heber, Maximilian Halenke, Aakash Bhat, Veronika Schaffenroth   +3 more
wiley   +1 more source

Compton Scattering of Electrons in the Intergalactic Medium

The Astrophysical Journal
This paper investigates the distribution and implications of cosmic-ray electrons within the intergalactic medium (IGM). Utilizing a synthesis model of the extragalactic background, we evolve the spectrum of Compton-included cosmic rays.
Yuanyuan Yang, Heyang Long, Christopher M. Hirata   +2 more
doaj   +1 more source

Study of the Parameters Affecting the Correlation of Background Versus Cosmic Radiation in Co₂ Counters: Reliability of Dating Results [PDF]

, 1997
Yorgos Facorellis, Yannis Maniatis, Bernd Kromer   +2 more
openalex   +1 more source

Standard Cosmic Ray Energetics and Light Element Production

, 2000
The recent observations of Be and B in metal poor stars has led to a reassessment of the origin of the light elements in the early Galaxy. At low it is metallicity ([O/H] < -1.75), it is necessary to introduce a production mechanism which is independent ...
B. D. Fields, Berezhko, Boesgaard, Boesgaard, Boesgaard, Buckley, Carretta, Cassé, Combi, Connell, Dragicevich, Drury, E. Vangioni-Flam, Engelmann, Fields, Fields, Fields, Fulbright, Garcia-Muñoz, Gilmore, Gratton, Henderson, Higdon, Hobbs, Israelian, Janni, K. A. Olive, King, Koyama, Lukasiak, M. Cassé, Mishenina, Molaro, Mori, Northcliffe, Primas, Ramaty, Ramaty, Ramaty, Ramaty, Ryan, Ryan, Ryter, Scalo, Simpson, Tanimori, Timmes, Vangioni-Flam, Vangioni-Flam, Vangioni-Flam, Webber   +50 more
core   +1 more source

Making it explicit – Sustained shared thinking dialogue as a way to explore children's perspectives on quality in German early childhood education and care

British Educational Research Journal, EarlyView.
Abstract To negotiate quality in early childhood education and care, we must ask from different perspectives what constitutes a good centre for children. The children themselves have only recently been identified as a resource to contribute to that discussion.
Katrin Macha, Frauke Hildebrandt, Caroline Wronski, Jan Lonnemann, Mathias Urban   +4 more
wiley   +1 more source