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Related papers: Cosmic Rays VII. Individual element spectra: predi…

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This review focuses on high-energy cosmic rays in the PeV energy range and above. Of particular interest is the knee of the spectrum around 3 PeV and the transition from cosmic rays of Galactic origin to particles from extra-galactic…

High Energy Astrophysical Phenomena · Physics 2013-03-15 Thomas K. Gaisser , Todor Stanev , Serap Tilav

We investigate the problem of transition from Galactic cosmic rays to extragalactic ultra high energy cosmic rays. Using the model for extragalactic ultra high energy cosmic rays and observed all-particle cosmic ray spectrum, we calculate…

Astrophysics · Physics 2009-11-10 V. S. Berezinsky , S. I. Grigorieva , B. I. Hnatyk

Observations of cosmic-ray electrons and positrons have been made with a new balloon-borne detector, HEAT (the "High-Energy Antimatter Telescope"), first flown in 1994 May from Fort Sumner, NM. We describe the instrumental approach and the…

Bohr's model agreed with the hydrogen spectrum results, but did not agree with the spectrum of Helium. Here we show that Bohr's model-based methods can calculate the experimental value (-79.005 eV) of Helium ground state energy correctly.…

Computational Physics · Physics 2009-03-17 Youhei Tsubono

We explore the feasibility of estimating primary cosmic ray composition at high energies from the study of two parameters of Extensive Air Showers (EAS) at ground and underground level with Monte Carlo simulations using the new EPOS and…

High Energy Astrophysical Phenomena · Physics 2015-01-12 A. Tapia , D. Melo , F. Sánchez , A. Sedoski Croce , J. M. Figueira , B. García , N. González , M. Josebachuili , D. Ravignani , B. Wundheiler , A. Etchegoyen

At variance from 2H, 3He and 4He abundances, 7Li abundance data yield an extra constraint to cosmological parameters, in top of those deriving from CMB, BAO, SNIa or H0 data. This constraint, often disregarded, would favor smaller $\Omega_b…

Cosmology and Nongalactic Astrophysics · Physics 2011-03-29 G. La Vacca , A. Valotti , S. A. Bonometto

Accurate modelling of the primary beam is an important but difficult task in radio astronomy. For high dynamic range problems such as 21cm intensity mapping, small modelling errors in the sidelobes and spectral structure of the beams can…

Instrumentation and Methods for Astrophysics · Physics 2024-07-25 Michael J. Wilensky , Jacob Burba , Philip Bull , Hugh Garsden , Katrine A. Glasscock , Nicolas Fagnoni , Eloy de Lera Acedo , David R. DeBoer , Nima Razavi-Ghods

A new molecular hydrogen cloud has been identified at z = 3.025 in the absorption-line spectrum of the quasar 0347-3819 observed with the UVES spectrograph at the VLT/Kueyen telescope. At the same redshift numerous metal lines and the DI…

Astrophysics · Physics 2007-05-23 S. A. Levshakov , P. Molaro , M. Dessauges-Zavadsky , S. D'Odorico

We have combined the detailed He I recombination model of Smits with the collisional transitions of Sawey & Berrington in order to produce new accurate helium emissivities that include the effects of collisional excitation from both the 2…

Astrophysics · Physics 2009-10-31 Robert A. Benjamin , Evan D. Skillman , Derck P. Smits

A model for high-energy (>10^14 eV) cosmic rays (HECRs) from galactic and extragalactic gamma-ray bursts (GRBs) is summarized. Relativistic outflows in GRBs are assumed to inject power-law distributions of CR protons and ions to the highest…

Astrophysics · Physics 2009-11-10 S. D. Wick , C. D. Dermer , A. Atoyan

I develop a theory to account for the cosmic ray spectrum. The essential assumption is that, due to fast convective motions, the free mean path perpendicular to the magnetic field is independent of energy and has the scale of the thickness…

Astrophysics · Physics 2007-05-23 Peter L. Biermann

The two electron configuration in the Helium atom is known to very high precision. Yet, we tend to refer to this configuration as a $1s\uparrow 1s\downarrow$ singlet, where the designations refer to Hydrogen orbitals. The high precision…

Atomic Physics · Physics 2015-11-17 J. Hutchinson , M. Baker , F. Marsiglio

In this work we present a detailed computation of the spectra of UHECR in the top-down scenario. We compare the spectra of hadrons obtained by two different methods in QCD and supersymmetric (SUSY) QCD with large primary energies $\sqrt{s}$…

Astrophysics · Physics 2009-11-10 R. Aloisio , V. Berezinsky , M. Kachelriess

The rate of oxygen formation determines the C/O ratio during stellar helium burning. It is the single most important nuclear input of stellar evolution theory including the evolution of Type II and Type Ia supernova. Yet the low energy…

Nuclear Experiment · Physics 2013-12-05 Moshe Gai

I give an overview of experimental and theoretical results for antiproton and antihydrogen scattering with atoms and molecules (in particular H, He). At low energies ($\lesssim1$~keV) there are practically no experimental data available.…

Atomic Physics · Physics 2018-08-31 Svante Jonsell

We present a measurement of the cosmic-ray electron+positron spectrum between 7 GeV and 2 TeV performed with almost seven years of data collected with the Fermi Large Area Telescope. We find that the spectrum is well fit by a broken power…

The cosmic ray electrons measured by Voyager 1 between 3-70 MeV beyond the heliopause have intensities several hundred times those measured at the Earth by PAMELA at nearly the same energies. This paper compares this new V1 data with data…

Space Physics · Physics 2017-04-03 W. R. Webber , T. L. Villa

Blazars with redshifts z<0.1 are likely candidates for detection at energies in the range 300 GeV - 50 TeV with Cerenkov telescopes and scintillator arrays. We present gamma-ray flux predictions for a sample of 15 nearby flat-spectrum radio…

Astrophysics · Physics 2011-05-23 K. Mannheim , S. Westerhoff , H. Meyer , H. -H. Fink