English
Related papers

Related papers: Sun-Heliosphere Observation-based Ionization Rates…

200 papers

The ionization parameter U is potentially useful for measuring radiation pressure feedback from massive star clusters, as it reflects the radiation-to-gas-pressure ratio and is readily derived from mid-infrared line ratios. We consider…

Astrophysics of Galaxies · Physics 2013-10-30 Sherry C. C. Yeh , Christopher D. Matzner

The emission line ratios [OIII]5007/H-beta and [NII]6584/H-alpha have been adopted as an empirical way to distinguish between the fundamentally different mechanisms of ionization in emission-line galaxies. However, detailed interpretation…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Sherry C. C. Yeh , Silvia Verdolini , Mark R. Krumholz , Christopher D. Matzner , Alexander G. G. M. Tielens

Observations of the Sun's surface suggest a nonuniform radiated flux as related to the presence of bright active regions and darker coronal holes. The variations of the FUV/EUV source radiation can be expected to affect the Lyman-alpha…

Solar and Stellar Astrophysics · Physics 2021-10-04 Marek Strumik , Maciej Bzowski , Marzena A. Kubiak

We present a study of the influence of solar UV anisotropy on the heliospheric backscatter helioglow generated by resonant scattering of solar Lyman-alpha photons on interstellar hydrogen atoms around the Sun. Simulations based on the…

Solar and Stellar Astrophysics · Physics 2023-12-22 M. Strumik , M. Bzowski , M. A. Kubiak

Our basic theoretical understanding of the sources of cosmic rays and their propagation through the interstellar medium is hindered by the Sun, that through the solar wind affects the observed cosmic-ray spectra. This effect is known as…

Solar and Stellar Astrophysics · Physics 2022-10-12 Ilias Cholis , Ian McKinnon

Variations in X-ray and EUV irradiance during solar flares lead to a noticeable increase in the electron concentration in the illuminated part of the Earth's ionosphere. Due to the large amount of experimental data accumulated by Global…

Earth and Planetary Astrophysics · Physics 2024-07-22 Susanna Bekker , Ryan Milligan , Ilya Ryakhovsky

We present new computations of the ionizing spectral energy distributions (SEDs) and Lyman continuum (Lyc) and HeI continuum photon emission rates, for hot O-type and early B-type stars. We consider solar metallicity stars, with effective…

Astrophysics · Physics 2009-11-10 Amiel Sternberg , Tadziu Hoffman , Adalbert Pauldrach

The cosmic rays differential intensity inside the heliosphere, for energy below 30 GeV/nuc, depends on solar activity and interplanetary magnetic field polarity. This variation, termed solar modulation, is described using a 2-D (radius and…

Solar and Stellar Astrophysics · Physics 2015-06-12 P. Bobik , G. Boella , M. J. Boschini , C. Consolandi , S. Della Torre , M. Gervasi , D. Grandi , K. Kudela , S. Pensotti , P. G. Rancoita , D. Rozza , M. Tacconi

The transport environment for particles in the heliosphere, e.g. galactic cosmic rays (GCRs) and MeV electrons (including those originating from Jupiters magnetosphere), is defined by the solar wind flow and the structure of the embedded…

High Energy Astrophysical Phenomena · Physics 2013-09-06 P. Kühl , N. Dresing , P. Dunzlaff , H. Fichtner , J. Gieseler , R. Gómez-Herrero , B. Heber , A. Klassen , J. Kleimann , A. Kopp , M. Potgieter , K. Scherer , R. D. Strauss

The differential intensities of Cosmic Rays at Earth were calculated using a 2D stochastic Montecarlo diffusion code and compared with observation data. We evaluated the effect of stretched and compressed heliospheres on the Cosmic Ray…

Solar and Stellar Astrophysics · Physics 2017-08-23 P. Bobik , M. J. Boschini , C. Consolandi , S. Della Torre , M. Gervasi , D. Grandi , K. Kudela , F. Noventa , S. Pensotti , P. G. Rancoita , D. Rozza

The composition of ions plays a crucial role for the fundamental plasma properties in the terrestrial magnetosphere. We investigate the oxygen-to-hydrogen ratio in the near-Earth magnetosphere from -10 RE<XGSE}< 10 RE. The results are based…

Earth and Planetary Astrophysics · Physics 2015-06-11 Elena A. Kronberg , Stein E. Haaland , Patrick W. Daly , Elena E. Grigorenko , Lynn Kistler , Markus Fränz , Iannis Dandouras

During the solar journey through galactic space, variations in the physical properties of the surrounding interstellar medium (ISM) modify the heliosphere and modulate the flux of galactic cosmic rays (GCR) at the surface of the Earth, with…

Astrophysics of Galaxies · Physics 2015-05-20 Priscilla C. Frisch , Hans-Reinhard Mueller

The radiation field of central stars of planetary nebulae (CSPNe) is crucial for determining the physical conditions of planetary nebulae (PNe). Many studies in the literature model PNe using the blackbody approximation (bb) or…

Solar and Stellar Astrophysics · Physics 2025-11-24 L. V. Da Conceição , W. LF. Marcolino , V. Maria

The total solar irradiance (TSI) varies on timescales of minute to centuries. On short timescales it varies due to the superposition of intensity fluctuations produced by turbulent convection and acoustic oscillations. On longer scale…

Solar and Stellar Astrophysics · Physics 2022-10-12 V. Penza , F. Berrilli , L. Bertello , M. Cantoresi , S. Criscuoli , P. Giobbi

Understanding effects of ionisation in the lower atmosphere is a new interdisciplinary area, crossing traditionally distinct scientific boundaries. Following the paper of Erlykin et al. (Astropart. Phys. 57--58 (2014) 26--29) we develop the…

Atmospheric and Oceanic Physics · Physics 2015-06-24 Karen Aplin , Mike Lockwood

Data obtained over the last three solar cycles have been analysed to reveal the relationships between the intensity of the photospheric field measured along the line of sight by the WSO group at heliolatitudes from -75 to 75 degrees and the…

Geophysics · Physics 2018-02-14 E. A. Gavryuseva

Space weather is a multidisciplinary research area connecting scientists from across heliophysics domains seeking a coherent understanding of our space environment that can also serve modern life and society's needs. COSPAR's ISWAT…

The cosmic-ray ionization rate ($\zeta_2$) is one of the key parameters in star formation, since it regulates the chemical and dynamical evolution of molecular clouds by ionizing molecules and determining the coupling between the magnetic…

Astrophysics of Galaxies · Physics 2024-10-23 Gan Luo , Thomas G. Bisbas , Marco Padovani , Brandt A. L. Gaches

We investigate the implications of the intergalactic opacity for the evolution of the cosmic UV luminosity density and its sources. Our main constraint is our measurement of the Lya forest opacity at redshifts 2<z<4.2 from 86…

Astrophysics · Physics 2009-11-13 C. -A. Faucher-Giguere , A. Lidz , L. Hernquist , M. Zaldarriaga

Experimental investigations of the fine plasma structure of interplanetary shocks are extremely difficult to conduct due to their small thickness and high speed relative to the spacecraft. We study the variations in the parameters of…

‹ Prev 1 4 5 6 7 8 10 Next ›