Now showing items 171-190 of 517

  • 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 ...
  • 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 ...
  • 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 ...
  • Wulser, J. P.; Jaeggli, S.; De Pontieu, Bart Walter; Tarbell, T; Boerner, P.; Freeland, S.; Liu, W.; Timmons, R.; Brannon, S; Kankelborg, C.; Madsen, C; McKillop, S.; Prchlik, J; Saar, S.; Schanche, N; Testa, P; Bryans, P.; Wiesmann, Martin (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2018)
    The Interface Region Imaging Spectrograph (IRIS) is a NASA small explorer mission that provides high-resolution spectra and images of the Sun in the 133 – 141 nm and 278 – 283 nm wavelength bands. The IRIS data are archived ...
  • Pereira, Tiago Mendes Domingos; De Pontieu, Bart Walter; Carlsson, Mats; Hansteen, Viggo; Tarbell, T.D.; Lemen, J.; Title, A.; Boerner, P.; Hurlburt, N.; Wulser, J. P.; Martinez-Sykora, Juan; Kleint, L.; Golub, L.; McKillop, S.; Reeves, K. K.; Saar, S.; Testa, Paola; Tian, H; Jaeggli, S.; Kankelborg, C. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2014)
    Solar spicules have eluded modelers and observers for decades. Since the discovery of the more energetic type II, spicules have become a heated topic but their contribution to the energy balance of the low solar atmosphere ...
  • Rouppe van der Voort, Luc; De Pontieu, Bart Walter; Scharmer, G. B.; de la Cruz Rodriguez, Jaime; Martinez-Sykora, Juan; Nobrega-Siverio, Daniel; Guo, L. J.; Jafarzadeh, Shahin; Mendes Domingos Pereira, Tiago; Hansteen, Viggo; Carlsson, Mats; Vissers, Gregal Joan Maria (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2017)
    Magnetic reconnection is thought to drive a wide variety of dynamic phenomena in the solar atmosphere. Yet, the detailed physical mechanisms driving reconnection are difficult to discern in the remote sensing observations ...
  • Martinez-Sykora, Juan; Rouppe, Van Der Voort Luc; Carlsson, Mats; De Pontieu, Bart Walter; Mendes Domingos Pereira, Tiago; Boerner, P.; Hurlburt, N.; Kleint, Lucia; Lemen, J.; Tarbell, Ted D.; Title, A.; Wüelser, Jean Pierre; Hansteen, Viggo; Golub, Leon; McKillop, S.; Reeves, K. K.; Saar, S.; Testa, Paola; Tian, Hui; Jaeggli, S.; Kankelborg, C. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2015)
    The Interface Region Imaging Spectrograph (IRIS) reveals small-scale rapid brightenings in the form of bright grains all over coronal holes and the quiet Sun. These bright grains are seen with the IRIS 1330, 1400, and 2796 ...
  • Groeneboom, Nicolaas Ervik; Dahle, Håkon (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2014)
    We developed a novel approach for fast and accurate ray-tracing of galaxies using procedural noise fields. Our method allows for efficient and realistic rendering of synthetic galaxy morphologies, where individual components ...
  • Hole, Ida Benedikte Amlie (Master thesis / Masteroppgave, 2012)
    The inverse-C shape of the bisector from the chromospheric Ca triplet spectral lines is a little understood phenomena. This spectral signature can give valuble information about the chromosphere, which is the least understood ...
  • Kanella, Charalambos; Gudiksen, Boris Vilhelm (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2018)
    Context: One candidate model for heating the solar corona is magnetic reconnection that embodies Ohmic dissipation of current sheets. When numerous small-scale magnetic reconnection events occur, then it is possible to ...
  • Polito, V.; Testa, Paola; Allred, J.; De Pontieu, Bart Walter; Carlsson, Mats; Pereira, Tiago Mendes Domingos; Gosic, M; Reale, F. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2018)
    We present the results of 1D hydrodynamic simulations of coronal loops that are subject to nanoflares, caused by either in situ thermal heating or nonthermal electron (NTE) beams. The synthesized intensity and Doppler ...
  • Bakke, Daniél Jimenez (Master thesis / Masteroppgave, 2019)
    Due to the accelerated expansion of the visible Universe, the Symmetron has been proposed as a modification of the standard Einstein field equations. I investigate the feasibility of the Symmetron in light of radial ...
  • Jordahl, Elisabeth (Master thesis / Masteroppgave, 2013)
  • Panesar, Navdeep K.; Sterling, Alphonse C.; Moore, Ronald L.; Tiwari, Sanjiv K.; De Pontieu, Bart Walter; Norton, Aimee A. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2018)
    Recent observations show that the buildup and triggering of minifilament eruptions that drive coronal jets result from magnetic flux cancelation at the neutral line between merging majority- and minority-polarity magnetic ...