Now showing items 236-255 of 516

  • 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 ...
  • Karman, W.; Caputi, K.; Caminha, G. B.; Gronke, Max Balthasar; Grillo, C.; Balestra, I.; Rosati, P.; Vanzella, E.; Coe, D.; Dijkstra, Mark; Koekemoer, A.; McLeod, D.; Mercurio, A.; Nonino, M. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2017)
    In spite of their conjectured importance for the Epoch of Reionization, the properties of low-mass galaxies are currently still very much under debate. In this article, we study the stellar and gaseous properties of faint, ...
  • Li, Baojiu; Mota, David; Barrow, J. D. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2011)
    We introduce the N-body simulation technique to follow structure formation in linear and nonlinear regimes for the extended quintessence models (scalar-tensor theories in which the scalar field has a self-interaction ...
  • Opheimsbakken, Håkon (Master thesis / Masteroppgave, 2014)
    Neutrinos are very weakly interacting particles with a low mass. In fact, the mass of the neutrinos has not yet been determined by experiments or observations. Still, neutrinos are a good candidate for some of the dark ...
  • Garay, Carlos Peña; Verde, Licia; Jimenez, Raul (Journal article / Tidsskriftartikkel / SubmittedVersion, 2017)
    Recent constrains on the sum of neutrino masses inferred by analyzing cosmological data, show that detecting a non-zero neutrino mass is within reach of forthcoming cosmological surveys. Such a measurement will imply a ...
  • Jenssen, Espen Sem (Master thesis / Masteroppgave, 2016)
    The universe is full of stuff we cannot see, neither directly or indirectly. We do not understand the nature of the mysterious dark matter and how it interacts with normal matter. Big Bang Nucleosynthesis (BBN) provides ...
  • Ovaldsen, Jan-Erik (Master thesis / Hovedoppgave, 2002)
    Five years (1992-1997, ~2650 images) of optical observations of the gravitational lens system QSO 0957+561 were analyzed using a new photometry package developed by Jan Teuber and me. My supervisor was Prof. Rolf Stabell, ...
  • Nagy, J. M.; Ade, P. A. R.; Amiri, M.; Benton, S. J.; Bergman, A. S.; Bihary, R.; Bock, J. J.; Bond, J. R.; Bryan, S. A.; Chiang, H. C.; Contaldi, C. R.; Doré, O.; Duivenvoorden, Adri J.; Eriksen, Hans Kristian Kamfjord; Farhang, M.; Filippini, J. P.; Fissel, L. M.; Fraisse, A. A.; Freese, K.; Galloway, M.; Gambrel, Anne E.; Gandilo, N. N.; Ganga, K.; Gudmundsson, J. E.; Halpern, M.; Hartley, J.; Hasselfield, M.; Hilton, G.; Holmes, W.; Hristov, V. V.; Huang, Z.; Irwin, K. D.; Jones, W. C.; Kuo, C. L.; Kermish, Z. D.; Li, S.; Mason, P. V.; Megerian, K.; Moncelsi, Lorenzo; Morford, T. A.; Netterfield, C. B.; Nolta, M.; Padilla, I. L.; Racine, Benjamin; Rahlin, A. S.; Reintsema, C.; Ruhl, J. E.; Runyan, M. C.; Ruud, Tone Melvær; Shariff, J. A.; Soler, J. D.; Song, X.; Trangsrud, A.; Tucker, C.; Tucker, R. S.; Turner, A. D.; Van der List, J. F.; Weber, A. C.; Wehus, Ingunn Kathrine; Wiebe, D. V.; Young, E. Y. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2017)
    © 2017. The American Astronomical Society. All rights reserved.
  • Kakiichi, Koki; Dijkstra, Mark (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2018)
    We present a new perturbative approach to ‘constrained Ly α radiative transfer’ (RT) through the circum- and intergalactic medium (CGM and IGM). We constrain the H I content and kinematics of the CGM and IGM in a physically ...
  • Golding, Thomas Peter; Leenaarts, Jorrit; Carlsson, Mats (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2016)
    The ionization state of the gas in the dynamic solar chromosphere can depart strongly from the instantaneous statistical equilibrium commonly assumed in numerical modeling. We improve on earlier simulations of the solar ...
  • Golding, Thomas Peter (Doctoral thesis / Doktoravhandling, 2017)
  • Rudjord, Øystein (Doctoral thesis / Doktoravhandling, 2010)