Browsing Institutt for teoretisk astrofysikk by Title

Now showing items 513-518 of 518

  • A weak lensing analysis of the PLCK G100.2-30.4 cluster 
    Radovich, M.; Formicola, I.; Meneghetti, M.; Bartalucci, I.; Bourdin, H.; Mazzotta, P.; Moscardini, L.; Ettori, S.; Arnaud, M.; Pratt, G. W.; Aghanim, N.; Dahle, Håkon; Douspis, M.; Pointecouteau, E.; Grado, A. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2015)
    We present a mass estimate of the Planck-discovered cluster PLCK G100.2-30.4, derived from a weak lensing analysis of deep Subaru griz images. We perform a careful selection of the background galaxies using the multi-band ...
  • What Causes the High Apparent Speeds in Chromospheric and Transition Region Spicules on the Sun? 
    De Pontieu, Bart Walter; Martinez-Sykora, Juan; Chintzoglou, Georgios (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2017)
    Spicules are the most ubuiquitous type of jets in the solar atmosphere. The advent of high-resolution imaging and spectroscopy from the Interface Region Imaging Spectrograph (IRIS) and ground-based observatories has revealed ...
  • WHAT DO IRIS OBSERVATIONS of Mg II k TELL US ABOUT THE SOLAR PLAGE CHROMOSPHERE? 
    Carlsson, Mats; Leenaarts, Jorrit; De Pontieu, Bart Walter (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2015)
    We analyze observations from the Interface Region Imaging Spectrograph of the Mg ii k line, the Mg ii UV subordinate lines, and the O i 135.6 $\mathrm{nm}$ line to better understand the solar plage chromosphere. We also ...
  • Why is non-thermal line broadening of spectral lines in the lower transition region of the sun independent of spatial resolution? 
    De Pontieu, Bart Walter; McIntosh, Scott; Martinez-Sykora, Juan; Peter, Hardi; Mendes Domingos Pereira, Tiago (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2015)
    Spectral observations of the solar transition region (TR) and corona show broadening of spectral lines beyond what is expected from thermal and instrumental broadening. The remaining non-thermal broadening is significant ...
  • Why is the Sun's corona so hot? Why are prominences so cool? 
    Zirker, Jack B.; Engvold, Oddbjørn (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2017)
    © 2017 American Institute of Physics.
  • Wormholes supported by hybrid metric-Palatini gravity 
    Capozziello, S.; Harko, T.; Koivisto, Tomi Sebastian; Lobo, F. S. N.; Olmo, G. J. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2012)
    Recently, a modified theory of gravity was presented, which consists of the superposition of the metric Einstein-Hilbert Lagrangian with an f(R) term constructed à la Palatini. The theory possesses extremely interesting ...