Now showing items 228-247 of 519

  • Harko, T.; Koivisto, Tomi Sebastian; Lobo, F. S. N.; Olmo, G. J. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2012)
    We present a novel approach to modified theories of gravity which consists of adding to the Einstein-Hilbert Lagrangian an f(R) term constructed à la Palatini. Using the respective dynamically equivalent scalar-tensor ...
  • Drews, Ainar; Rouppe van der Voort, Luc (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2017)
    Context. Penumbral microjets (PMJs) are short-lived jets found in the penumbra of sunspots, first observed in wide-band Ca ii H line observations as localized brightenings, and are thought to be caused by magnetic reconnection. ...
  • Loukitcheva, M.; Solanki, S. K.; Carlsson, Mats; White, S. M. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2015)
    Aims: We use advanced 3D non-local thermodynamic equilibrium radiative magnetohydrodynamic simulations of the solar atmosphere to carry out detailed tests of chromospheric diagnostics at millimeter and submillimeter ...
  • Loukitcheva, M.; White, S. M.; Solanki, S. K.; Fleishman, G. D.; Carlsson, Mats (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2017)
    Aims. We use state-of-the-art, three-dimensional non-local thermodynamic equilibrium (non-LTE) radiative magnetohydrodynamic simulations of the quiet solar atmosphere to carry out detailed tests of chromospheric magnetic ...
  • Børve, Steinar; Sato, Hiroatsu; Pecseli, Hans; Trulsen, Jan Karsten (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2011)
    Oscillations with periods on the order of 5–10 min have been observed by instrumented spacecrafts in the Earth's magnetosphere. These oscillations often follow sudden impacts related to coronal mass ejections. It is ...
  • Gronke, Max Balthasar (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2017)
    We compare 237 Lyman-α (Lyα) spectra of the MUSE-Wide survey to a suite of radiative transfer simulations consisting of a central luminous source within a concentric, moving shell of neutral gas, and dust. This six parameter ...
  • Voivodic, Rodrigo; Lima, Marcos; Llinares, Claudio; Mota, David (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2017)
    © 2017 American Physical Society
  • Bø, Iselin M Thomassen (Master thesis / Masteroppgave, 2008)
    Systematic anomalies that seem to follow the first ionisation potential (FIP) of the minor, heavy elements at the sun, have been found when comparing the observed elemental abundances in the upper solar atmosphere with the ...
  • Pucci, Stefano (Master thesis / Masteroppgave, 2008)
    In-situ observations together with spectroscopic measurements show that the elemental abundance in the solar atmosphere varies from the photosphere to solar wind. An enrichment for low First Ionisation Potential elements ...
  • Hodne, Espen (Master thesis / Masteroppgave, 2019)
    I calculate Lyman-α luminosity and surface brightness; and find that the values are much higher than typical for this kind of galaxy. I find this is due to very high star formation rate; which makes the galaxy superluminous.
  • Forero-Romero, J. E.; Gronke, Max Balthasar; Remolina-Gutiérrez, Maria Camila; Gravito-Camargo, Nicolás; Dijkstra, Mark (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2017)
    © 2017 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society
  • Svendsen, Øyvind Brynhildsvoll (Master thesis / Masteroppgave, 2018)
    The nuclide 187Re beta-decays to 187Os with a half-life of approximately 41.6 Gyr. The long half-life and simple relation between 187Re and 187Os makes the ratio a good candidate for a cosmic clock. In order to "use the ...
  • Ranjan, A.; Noterdaeme, P.; Krogager, J.-K.; Petitjean, Patrick; Balashev, S. A.; Bialy, S.; Srianand, R.; Gupta, N.; Fynbo, J. P. U.; Ledoux, C.; Laursen, Peter (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2018)
    We present the detection and detailed analysis of a diffuse molecular cloud at zabs = 2.4636 towards the quasar SDSS J 1513+0352 (zem ≃ 2.68) observed with the X-shooter spectrograph at the Very Large Telescope. We measured ...
  • Wehus, Ingunn Kathrine; Fuskeland, Unni; Eriksen, Hans Kristian Kamfjord; Banday, Anthony J.; Dickinson, Clare F.; Ghosh, Tuhin Subhra; Górski, Krzysztof M.; Lawrence, Cecil R.; Leahy, J. Patrick; Maino, Davide Biagi; Reich, Patricia; Reich, Wolfgang (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2017)
    We describe a simple but efficient method for deriving a consistent set of monopole and dipole corrections for multi-frequency sky map data sets, allowing robust parametric component separation with the same data set. The ...
  • Gafeira, Ricardo; Lagg, A.; Solanki, S. K.; Jafarzadeh, Shahin; van Noort, M.; Barthol, P.; Blanco Rodriguez, J.; del Toro Iniesta, J. C.; Gandorfer, A.; Gizon, L; Hirzberger, J.; Knölker, M.; Orozco Suarez, D.; Riethmüller, T. L.; Schmidt, W. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2017)
    We use seeing-free high spatial resolution Ca ii H data obtained by the Sunrise observatory to determine properties of slender fibrils in the lower solar chromosphere. In this work we use intensity images taken with the ...
  • Chamandy, Tiffany Marie (Master thesis / Masteroppgave, 2018)
  • Seljebotn, Dag Sverre; Mardal, Kent-Andre; Jewell, J. B.; Eriksen, Hans Kristian Kamfjord; Bull, Philip James (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2014)
    We present a multi-level solver for drawing constrained Gaussian realizations or finding the maximum likelihood estimate of the cosmic microwave background sky, given noisy sky maps with partial sky coverage. The method ...
  • Antolin, Patrick; Vissers, Gregal Joan Maria; Mendes Domingos Pereira, Tiago; Rouppe, Van Der Voort Luc; Scullion, Eamon (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2015)
    We analyze coordinated observations of coronal rain in loops, spanning chromospheric, transition region (TR), and coronal temperatures with sub-arcsecond spatial resolution. Coronal rain is found to be a highly multithermal ...
  • Izadparast, Masoumeh (Master thesis / Masteroppgave, 2015)
    Magnetic bright points (MBPs) are small-scale (generally kG) magnetic features, ubiqui- tous in the lower solar atmosphere, and are a manifestation of solar magnetism. They represent the cross-sections of thin flux tubes ...
  • Shetye, Juie; Verwichte, Erwin; Stangalini, Marco; Judge, Philip G.; Doyle, J. G.; Arber, Tony; Scullion, Eamon; Wedemeyer, Sven (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)
    e report observations of small-scale swirls seen in the solar chromosphere. They are typically 2 Mm in diameter and last around 10 minutes. Using spectropolarimetric observations obtained by the CRisp Imaging Spectro-Polarimeter ...