Now showing items 485-504 of 602

  • Mas Ribas, Lluis (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)
    We report on quasar outflow properties revealed by analyzing more than 60 composite outflow spectra built from ~60,000 C iv absorption troughs in the SDSS-III/BOSS DR12QBAL catalog. We assess the dependences of the equivalent ...
  • Hong, Jie; Carlsson, Mats; Ding, M. D. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2017)
    Ellerman bombs (EBs) are brightenings in the Hα line wings that are believed to be caused by magnetic reconnection in the lower atmosphere. To study the response and evolution of the chromospheric line profiles, we perform ...
  • Osborne, Christopher M. J.; Armstrong, John A.; Fletcher, Lyndsay (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)
    During a solar flare, it is believed that reconnection takes place in the corona followed by fast energy transport to the chromosphere. The resulting intense heating strongly disturbs the chromospheric structure and induces ...
  • Rouppe, Van Der Voort Luc; Rutten, Robert; Vissers, Gregal Joan Maria (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2016)
    We describe a new quiet-Sun phenomenon which we call quiet-Sun Ellerman-like brightenings (QSEB). QSEBs are similar to Ellerman bombs (EB) in some respects but differ significantly in others. EBs are transient brightenings ...
  • Huse, Tor Helge (Master thesis / Hovedoppgave, 2005)
    During inflation, the potential of the inflaton scalar field $\phi$, drives the exponential expansion of the Universe. The nature of the inflaton potential is presently unknown, but one hopes to learn more from observations ...
  • Sainz Dalda, Alberto; de la Cruz Rodriguez, Jaime; De Pontieu, Bart Walter; Gošić, Milan (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)
    Inversion codes allow the reconstruction of a model atmosphere from observations. With the inclusion of optically thick lines that form in the solar chromosphere, such modeling is computationally very expensive because a ...
  • Barve, Christopher Backløf (Master thesis / Masteroppgave, 2016)
    Recent observations support a significantly reduced visibility of Lyman-α (Lyα) flux from galaxies at redshifts z > 6. This is surprising considering that the visibility of Lyα flux has been observed to increase up towards ...
  • Baumschlager, Bernhard; Hensler, Gerhard; Steyrleithner, Patrick; Recchi, Simone (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2018)
    We present, for the first time, numerical simulations of young tidal dwarf galaxies (TDGs), including a self-consistent treatment of the tidal arm in which they are embedded. Thereby, we do not rely on idealized initial ...
  • Llinares, Claudio; Mota, David (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2013)
    Several extensions of general relativity and high energy physics include scalar fields as extra degrees of freedom. In the search for predictions in the nonlinear regime of cosmological evolution, the community makes use ...
  • Unknown author (Series / Serietittel, 1950)
  • Howson, T. A.; de Moortel, Ineke; Antolin, Patrick; Van Doorsselaere, Tom; Wright, A. N. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)
    Aims. We investigate the transfer of energy between a fundamental standing kink mode and azimuthal Alfvén waves within an expanding coronal magnetic flux tube. We consider the process of resonant absorption in a loop with ...
  • Okamoto, T. J.; Antolin, Patrick; De Pontieu, Bart Walter; Uitenbroek, Han; Van Doorsselaere, Tom; Yokoyama, T (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2015)
    Transverse magnetohydrodynamic waves have been shown to be ubiquitous in the solar atmosphere and can, in principle, carry sufficient energy to generate and maintain the Sun's million-degree outer atmosphere or corona. ...
  • Gronke, Max Balthasar; Dijkstra, Mark; McCourt, Michael; Peng Oh, S. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2017)
    Motivated by observational and theoretical work that suggest very small-scale (≲ 1 pc) structure in the circumgalactic medium of galaxies and in other environments, we study Lyman-α (Lyα) radiative transfer in an extremely ...
  • Mas Ribas, Lluis; Hennawi, Joseph F (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2018)
    The baryonic content and physical properties of the warm and hot (105 lesssim T lesssim 107 K) phases of the circumgalactic medium (CGM) are poorly constrained owing to the lack of observables probing the requisite range ...
  • Mendes Domingos Pereira, Tiago; Uitenbroek, Han (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2015)
    The emergence of three-dimensional magneto-hydrodynamic simulations of stellar atmospheres has sparked a need for efficient radiative transfer codes to calculate detailed synthetic spectra. We present RH 1.5D, a massively ...
  • Sahlu, Shambel; Ntahompagaze, Joseph; Abebe, Amare; de la Cruz Dombriz, Álvaro; Mota, David (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2020)
  • Vargas dos santos, Marcelo; Alcaniz, Jailson S; Mota, David; Capozziello, Salvatore (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2018)
    We investigate the efficiency of screening mechanisms in the hybrid metric-Palatini gravity. The value of the field is computed around spherical bodies embedded in a background of constant density. We find a thin shell ...
  • Koivisto, Tomi Sebastian; Mota, David; Zumalacárregui, Miguel (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2012)
    It is shown that extensions to general relativity, which introduce a strongly coupled scalar field, can be viable if the interaction has a nonconformal form. Such disformal coupling depends upon the gradients of the scalar ...
  • Aviles, Alejandro; Cervantes-Cota, Jorge L; Mota, David (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)
    We present a formalism to study screening mechanisms in modified theories of gravity through perturbative methods in different cosmological scenarios. We consider Einstein-frame posed theories that are recast as Jordan-frame ...
  • Dahle, Håkon; Gladders, M. D.; Sharon, K.; Bayliss, M. B.; Wuyts, E; Abramson, L. E.; Koester, B. P.; Groeneboom, Nicolaas Ervik; Brinckmann, T. E.; Kristensen, M. T.; Lindholmer, M. O.; Nielsen, A; Krogager, J.-K.; Fynbo, J.P.U. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2013)
    We report the discovery of a unique gravitational lens system, SDSS J2222+2745, producing five spectroscopically confirmed images of a zs = 2.82 quasar lensed by a foreground galaxy cluster at zl = 0.49. We also present ...