Now showing items 153-172 of 518

  • Tennøe, Simen (Master thesis / Masteroppgave, 2013)
    Modified gravity theories are a popular research field in the hope that they could explain some of the unanswered questions in cosmology, for example how the universe starts, evolves and ends. One way to test proposed ...
  • Grönke, Max Balthasar; Llinares, Claudio; Mota, David; Winther, Hans Arnold (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2015)
    Screened modified gravity predicts potentially large signatures in the peculiar velocity field that makes it an interesting probe to test gravity on cosmological scales. We investigate the signatures induced by the Symmetron ...
  • de la Cruz Rodriguez, Jaime; De Pontieu, Bart; Carlsson, Mats; Rouppe, Van Der Voort Luc (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2013)
    The heating of the Sun's chromosphere remains poorly understood. While progress has been made on understanding what drives the quiet-Sun internetwork chromosphere, chromospheric heating in strong magnetic field regions ...
  • Rouppe, Van Der Voort Luc; De Pontieu, Bart Walter; Mendes Domingos Pereira, Tiago; Carlsson, Mats; Hansteen, Viggo (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2015)
    We use coordinated observations with the Interface Region Imaging Spectrograph (IRIS) and the Swedish 1 m Solar Telescope to identify the disk counterpart of type II spicules in upper-chromospheric and transition region ...
  • Wilson, Paul A. (Master thesis / Masteroppgave, 2010)
  • Olsen, Øystein (Doctoral thesis / Doktoravhandling, 2007)
    Doktorgradsavhandlingen beskriver et programvarebibliotek utviklet av Øystein Olsen ved Institutt for teoretisk astrofysikk. Programvaren har blitt brukt til å finne regioner med stabile og ustabile baner rundt asteroider ...
  • Skogsrud, Håkon (Master thesis / Masteroppgave, 2011)
    Spicules are relatively small, narrow and elongated structures that stick out above the edge of the solar disk. They are very dynamic and appear as jets that shoot out into the outer solar atmosphere. Up until recently, ...
  • Jafarzadeh, Shahin; Solanki, S. K.; Stangalini, M.; Steiner, Oskar; Cameron, R. H.; Danilovic, S. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2017)
    We characterize waves in small magnetic elements and investigate their propagation in the lower solar atmosphere from observations at high spatial and temporal resolution. We use the wavelet transform to analyze oscillations ...
  • Petrushevska, T.; Amanullah, R.; Goobar, A.; Fabbro, S.; Johansson, J.; Kjellsson, T.; Lidman, C.; Paech, K.; Richard, J.; Dahle, Håkon; Ferretti, R.; Kneib, J.-P.; Limousin, M.; Nordin, J.; Stanishev, V. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2016)
    Aims. We present a ground-based, near-infrared search for lensed supernovae behind the massive cluster Abell 1689 at z = 0.18, which is one of the most powerful gravitational telescopes that nature provides. Methods. Our ...
  • Tian, H; DeLuca, E.; Reeves, K. K.; McKillop, S.; De Pontieu, Bart Walter; Martinez-Sykora, Juan; Carlsson, Mats; Hansteen, Viggo; Kleint, L.; Cheung, M; Golub, L.; Saar, S.; Testa, Paola; Weber, M.; Lemen, J.; Title, A.; Boerner, P.; Hurlburt, N.; Tarbell, T.D.; Wuelser, J. P.; Kankelborg, C.; Jaeggli, S.; McIntosh, S.W. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2014)
    We present the first results of sunspot oscillations from observations by the Interface Region Imaging Spectrograph. The strongly nonlinear oscillation is identified in both the slit-jaw images and the spectra of several ...
  • Skogvoll, Marte Elisabeth (Master thesis / Masteroppgave, 2007)
  • Cheung, Mark C. M.; De Pontieu, Bart Walter; Tarbell, Theodore D.; Fu, Y.; Tian, H.; Testa, Paola; Reeves, K. K.; Martinez-Sykora, Juan; Boerner, P.; Wulser, J. P.; Lemen, J.; Title, Alan M.; Hurlburt, N.; Kleint, L.; Kankelborg, C.; Jaeggli, S.; Golub, L.; McKillop, S.; Saar, S.; Carlsson, Mats; Hansteen, Viggo (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2015)
    We report on observations of recurrent jets by instruments on board the Interface Region Imaging Spectrograph, Solar Dynamics Observatory (SDO), and Hinode spacecraft. Over a 4 hr period on 2013 July 21, recurrent coronal ...
  • de Jorge Henriques, Vasco Manuel; Mathioudakis, M.; Socas-Navarro, H.; de la Cruz Rodriguez, Jaime (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2017)
    We perform non-LTE inversions in a large set of umbral flashes, including the dark fibrils visible within them, and in the quiescent umbra by using the inversion code NICOLE on a set of full Stokes high-resolution Ca ii ...
  • 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 ...
  • 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 ...
  • 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 ...