Now showing items 214-233 of 652

  • Pace, Francesco; Schimd, Carlo; Mota, David; Del Popolo, Antonino (Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2019)
    The evolution of the virial overdensity Δvir for ΛCDM and seven dynamical dark-energy models is investigated in the extended spherical collapse model (SCM). Here the virialization process is naturally achieved by introducing ...
  • 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)
  • Murabito, M.; Ermolli, I.; Giorgi, F.; Stangalini, M.; Guglielmino, S. L.; Jafarzadeh, Shahin; Socas-Navarro, H.; Romano, P.; Zuccarello, F. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)
    We studied the physical parameters of the penumbra in a large and fully developed sunspot, one of the largest over the last two solar cycles, by using full-Stokes measurements taken at the photospheric Fe i 617.3 nm and ...
  • 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 ...
  • Panesar, Navdeep K.; Sterling, Alphonse C.; Moore, Ronald L.; Winebarger, Amy R.; Tiwari, Sanjiv K.; Savage, Sabrina L.; Golub, Leon E.; Rachmeler, Laurel A.; Kobayashi, Ken; Brooks, David H.; Cirtain, Jonathan W.; De Pontieu, Bart Walter; McKenzie, David E.; Morton, Richard J.; Peter, Hardi; Testa, Paola; Walsh, Robert W.; Warren, Harry P. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)
    We present high-resolution, high-cadence observations of six, fine-scale, on-disk jet-like events observed by the High-resolution Coronal Imager 2.1 (Hi-C 2.1) during its sounding-rocket flight. We combine the Hi-C 2.1 ...
  • 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 ...
  • Rouppe van der Voort, Luc; De Pontieu, Bart Walter; Carlsson, Mats; de la Cruz Rodriguez, Jaime; Bose, Souvik; Chintzoglou, Georgios; Drews, Ainar; Froment, Clara; Gošić, Milan; Graham, David R.; Hansteen, Viggo; de Jorge Henriques, Vasco Manuel; Jafarzadeh, Shahin; Joshi, Jayant; Kleint, Lucia; Kohutova, Petra; Leifsen, Torben; Martinez-Sykora, Juan; Nóbrega Siverio, Daniel Elias; Ortiz, Ada; Mendes Domingos Pereira, Tiago; Popovas, Andrius; Quintero Noda, Carlos; Sainz Dalda, Alberto; Scharmer, Göran B.; Schmit, Donald; Scullion, Eamon; Skogsrud, Håkon; Szydlarski, Mikolaj Marcin; Timmons, R.; Vissers, Gregal Joan Maria; Woods, M. M.; Zacharias, Pia (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2020)
    NASA’s Interface Region Imaging Spectrograph (IRIS) provides high-resolution observations of the solar atmosphere through ultraviolet spectroscopy and imaging. Since the launch of IRIS in June 2013, we have conducted ...
  • Keys, Peter H.; Reid, Aaron L.; Mathioudakis, Mihalis; Shelyag, Sergey I.; de Jorge Henriques, Vasco Manuel; Hewitt, Rebecca L.; del Moro, Dario; Jafarzadeh, Shahin; Jess, David B.; Stangalini, Marco (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2020)
    Context. Magnetic bright points (MBPs) are dynamic, small-scale magnetic elements often found with field strengths of the order of a kilogauss within intergranular lanes in the photosphere. Aims. Here we study the evolution ...
  • 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 ...
  • 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 ...