Now showing items 263-282 of 722

  • Hudson, Hugh S.; Simões, Paulo J. A.; Fletcher, Lyndsay; Hayes, Laura A.; Hannah, Iain G. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2020)
    ABSTRACT The study of the localized plasma conditions before the impulsive phase of a solar flare can help us understand the physical processes that occur leading up to the main flare energy release. Here, we ...
  • Smith, Brent M.; Windhorst, Rogier A.; Jansen, Rolf A.; Cohen, Seth H.; Jiang, Linhua; Dijkstra, Mark; Koekemoer, Anton M.; Bielby, Richard; Inoue, Akio K.; MacKenty, John W.; O'Connell, Robert W.; Silk, Joseph I. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2018)
    We present observations of escaping Lyman Continuum (LyC) radiation from 34 massive star-forming galaxies (SFGs) and 12 weak AGN with reliably measured spectroscopic redshifts at $z\simeq 2.3\mbox{--}4.1$. We analyzed ...
  • Bose, Benjamin; Winther, Hans Arnold; Pourtsidou, Alkistis; Casas, Santiago; Lombriser, Lucas; Xia, Qianli; Cataneo, Matteo (Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2020)
    Constraints on gravity and cosmology will greatly benefit from performing joint clustering and weak lensing analyses on large-scale structure data sets. Utilising non-linear information coming from small physical scales ...
  • Hammami, Amir; Llinares, Claudio; Mota, David; Winther, Hans Arnold (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2015)
    In this paper, we present the first results from implementing two scalar–tensor modified gravity theories, the symmetron and the Hu–Sawicki f(R)-gravity model, into a hydrodynamic N-body code with dark matter particles and ...
  • Kowalski, Adam F.; Allred, Joel C.; Uitenbroek, Han; Tremblay, Pier-Emmanuel; Brown, Stephen; Carlsson, Mats; Osten, R. A.; Wisniewski, John P.; Hawley, Suzanne L. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2017)
    The broadening of the hydrogen lines during flares is thought to result from increased charge (electron, proton) density in the flare chromosphere. However, disagreements between theory and modeling prescriptions have ...
  • Golding, Thomas Peter (Master thesis / Masteroppgave, 2010)
    The solar chromosphere is a region where the thermodynamics are out of equilibrium, and realistic values of temperature and electron densities here are difficult to obtain. Hydrogen, being the most abundant element in solar ...
  • Capparelli, Vincenzo; Zuccarello, Francesca; Romano, Paolo; Simões, Paulo J. A.; Fletcher, Lyndsay; Kuridze, D.; Mathioudakis, M.; Keys, Peter H.; Cauzzi, Gianna; Carlsson, Mats (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2017)
  • Kuridze, D.; Mathioudakis, M.; Simoes, P. J. A.; Rouppe, Van Der Voort Luc; Carlsson, Mats; Jafarzadeh, Shahin; Allred, J. C.; Kowalski, Adam F.; Kennedy, M; Fletcher, L.; Graham, D.; Keenan, F. P. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2015)
    The asymmetries observed in the line profiles of solar flares can provide important diagnostics of the properties and dynamics of the flaring atmosphere. In this paper the evolution of the Hα and Ca ii λ8542 lines are ...
  • Engvold, Oddbjørn (Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2018)
    The IAU promotes astronomy as a tool to strengthen science education of young people in developing regions through its International Schools for Young Astronomers (ISYA) and a Teaching for Astronomy Development (TAD) ...
  • Kanella, Charalambos; Gudiksen, Boris Vilhelm (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2017)
    Context. The solar coronal heating problem has been an open question in the science community since 1939. One of the proposed models for the transport and release of mechanical energy generated in the sub-photospheric ...
  • Vanzella, E.; Balestra, I.; Gronke, Max Balthasar; Karman, W.; Caminha, G. B.; Dijkstra, Mark; Rosati, P.; De Barros, S.; Caputi, K.; Grillo, C.; Tozzi, P.; Meneghetti, M.; Mercurio, A.; Gilli, R. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2017)
    We report the identification of extended Lyα nebulae at z ≃ 3.3 in the Hubble Ultra Deep Field (HUDF, ≃40 kpc × 80 kpc) and behind the Hubble Frontier Field galaxy cluster MACSJ0416 (≃40 kpc), spatially associated with ...
  • Parmer, Asbjørn Lie (Master thesis / Masteroppgave, 2014)
    The chromosphere is nearly translucent in the optical and infrared continuum, making it an elusive observational target. In this thesis, I use a CO5BOLD computational 3D radiation magnetohydrodynamics (MHD) model of the ...
  • Klevas, J.; Kučinskas, A.; Wedemeyer, Sven; Ludwig, H.-G. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2018)
    We use 3D magnetohydrodynamic CO5BOLD model atmospheres to study the interplay between magnetic fields and convection in the atmospheres of red giant stars. We find that vortex-like structures occur prominently in stars ...
  • Martinez-Sykora, Juan; De Moortel, Ineke; De Pontieu, Bart Walter; Hansteen, Viggo; Carlsson, Mats (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2018)
    The role of type II spicules in the corona has been a much debated topic in recent years. This paper aims to shed light on the impact of type II spicules in the corona using novel 2.5D radiative MHD simulations, including ...
  • Antolin, Patrick (Doctoral thesis / Doktoravhandling, 2012)
  • Toresen, Mikael (Master thesis / Masteroppgave, 2015)
    In this thesis we have implemented a basic radiative transfer code to model the radial Lyα scattering rate around the epoch when the first stars and galaxies start forming, and ionizing their surroundings. The model, builds ...
  • Mertens, Florent G.; Mevius, M.; Koopmans, Leon V. E.; Offringa, A. R.; Mellema, Garrelt; Zaroubi, Saleem; Brentjens, M. A.; Gan, H.; Gehlot, Bharat Kumar; Pandey, V. N.; Sardarabadi, A. M.; Vedantham, Harish K.; Yatawatta, Sarod; Asad, Khan M. B.; Ciardi, B.; Chapman, Emma; Gazagnes, S.; Ghara, R.; Ghosh, Abhik; Giri, Sambit Kumar; Iliev, Ilian T.; Jelić, Vibor; Kooistra, Robin; Mondal, Rajesh; Schaye, Joop; Silva, Marta Bruno (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2020)
    A new upper limit on the 21 cm signal power spectrum at a redshift of z ≈ 9.1 is presented, based on 141 h of data obtained with the Low-Frequency Array (LOFAR). The analysis includes significant improvements in spectrally ...
  • Svalheim, Trygve Leithe (Master thesis / Masteroppgave, 2018)
    The Planck satellite has provided a multitude of data images of the full microwave sky, or sky maps, since it saw first light in 2009. Its observations of the Cosmic Microwave Background (CMB) data has been paramount in ...
  • Sekse, Dan Henrik (Doctoral thesis / Doktoravhandling, 2013)
  • Ishikawa, R.; Trujillo Bueno, J.; Uitenbroek, Han; Kubo, M.; Tsuneta, S.; Goto, M.; Kano, R.; Narukage, N.; Bando, T.; Katsukawa, Y.; Ishikawa, S.; Giono, G.; Suematsu, Y.; Hara, H.; Shimizu, T.; Sakao, T.; Winebarger, A.; Kobayashi, K.; Cirtain, J.; Champey, P.; Auchère, F.; Stepan, Jiri; Belluzzi, L.; Asensio Ramos, A.; Manso Sainz, R.; De Pontieu, Bart Walter; Ichimoto, K.; Carlsson, Mats; Casini, R. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2017)
    The Chromospheric Lyman-Alpha Spectro-Polarimeter is a sounding rocket experiment that has provided the first successful measurement of the linear polarization produced by scattering processes in the hydrogen Lyα line ...