Browsing Institutt for teoretisk astrofysikk by Title

Now showing items 323-342 of 1277

  • A DETAILED COMPARISON BETWEEN THE OBSERVED AND SYNTHESIZED PROPERTIES OF A SIMULATED TYPE II SPICULE 
    Martinez-Sykora, Juan; De Pontieu, Bart Walter; Leenaarts, Jorrit; Pereira, Tiago Mendes Domingos; Carlsson, Mats; Hansteen, Viggo; Stern, J. V.; Tian, H; McIntosh, S.W.; Rouppe, Van Der Voort Luc (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2013)
    We have performed a three-dimensional radiative MHD simulation of the solar atmosphere. This simulation shows a jet-like feature that shows similarities to the type II spicules observed for the first time with Hinode's ...
  • Detailed Description of the Collision Frequency in the Solar Atmosphere 
    Wargnier, Q.M.; Martinez-Sykora, Juan; Hansteen, Viggo Haraldson; De Pontieu, Bart Walter (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2022)
    This work aims to provide an accurate description and calculations of collision frequencies in conditions relevant to the solar atmosphere. To do so, we focus on the detailed description of the collision frequency in the ...
  • Detecting the neutral IGM in filaments with the SKA 
    Kooistra, Robin; Silva, Marta Bruno; Zaroubi, Saleem; Verheijen, Marc A. W.; Tempel, Elmo; Hess, Kelly M. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)
    The intergalactic medium (IGM) plays an important role in the formation and evolution of galaxies. Recent developments in upcoming radio telescopes are starting to open up the possibility of making a first direct detection ...
  • Detection of supersonic downflows and associated heating events in the transition region above sunspots 
    Kleint, L.; Antolin, Patrick; Tian, H; Judge, Philip G.; Testa, Paola; De Pontieu, Bart Walter; Martinez-Sykora, Juan; Reeves, K. K.; Wuelser, J. P.; McKillop, S.; Saar, S.; Carlsson, Mats; Boerner, P.; Hurlburt, N.; Lemen, J.; Tarbell, T.D.; Title, A.; Golub, L.; Hansteen, Viggo; Jaeggli, S.; Kankelborg, C. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2014)
    Interface Region Imaging Spectrograph data allow us to study the solar transition region (TR) with an unprecedented spatial resolution of 0farcs33. On 2013 August 30, we observed bursts of high Doppler shifts suggesting ...
  • Detection of the significant impact of source clustering on higher order statistics with DES Year 3 weak gravitational lensing data 
    Gatti, M.; Jeffrey, N.; Whiteway, L.; Ajani, V.; Kacprzak, T.; Zürcher, D.; Chang, C.; Jain, B.; Blazek, J.; Krause, E.; Alarcon, A.; Amon, A.; Bechtol, K.; Becker, M.; Bernstein, G.; Campos, A.; Chen, R.; Choi, A.; Davis, C.; DeRose, J.; Diehl, H.T.; Dodelson, S.; Doux, C.; Eckert, K.; Elvin-Poole, J.; Everett, S.; Ferte, A.; Gruen, D.; Gruendl, R.; Harrison, I.; Hartley, W.G.; Herner, K.; Huff, E.M.; Jarvis, M.; Kuropatkin, N.; Leget, P.F.; MacCrann, N.; McCullough, J.; Myles, J.; Navarro-Alsina, A.; Pandey, S.; Prat, J.; Raveri, M.; Rollins, R.P.; Roodman, A.; Sanchez, C.; Secco, L.F.; Sevilla-Noarbe, I.; Sheldon, E.; Shin, T.; Troxel, M.; Tutusaus, I.; Varga, T.N.; Yanny, B.; Yin, B.; Zhang, Y.; Zuntz, Joseph; Allam, S.S.; Alves, O.; Aguena, M.; Bacon, D.; Bertin, E.; Brooks, D.; Burke, D.L.; Carnero Rosell, A.; Carretero, J.; Cawthon, R.; da Costa, L. N.; Davis, T.M.; De Vicente, J.; Desai, S.; Doel, P.; García-Bellido, J.; Giannini, G.; Gutierrez, G.; Ferrero, Ismael; Frieman, J.; Hinton, S.R.; Hollowood, D.L.; Honscheid, K.; James, D.J.; Kuehn, K.; Lahav, O.; Marshall, J.L.; Mena-Fernández, J.; Miquel, R.; Ogando, R.L.C.; Palmese, A.; Pereira, M.E.S.; Plazas Malagón, A. A.; Rodriguez-Monroy, M.; Samuroff, S.; Sanchez, E.; Schubnell, M.; Smith, M.; Sobreira, F.; Suchyta, E.; Swanson, M.E.C.; Tarle, G.; Weaverdyck, N.; Wiseman, P. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2023)
    ABSTRACT We measure the impact of source galaxy clustering on higher order summary statistics of weak gravitational lensing data. By comparing simulated data with galaxies that either trace or do not trace the ...
  • The detection of upwardly propagating waves channeling energy from the chromosphere to the low corona 
    Freij, N.; Scullion, Eamon; Nelson, C. J.; Mumford, S.; Wedemeyer-Böhm, Sven; Erdélyi, R. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2014)
    There have been ubiquitous observations of wave-like motions in the solar atmosphere for decades. Recent improvements to space- and ground-based observatories have allowed the focus to shift to smaller magnetic structures ...
  • Diagnostic capabilities of spectropolarimetric observations for understanding solar phenomena: I. Zeeman-sensitive photospheric lines 
    Quintero Noda, Carlos; Barklem, P. S.; Gafeira, Ricardo; Ruiz Cobo, Basilio; Collados, Manuel; Carlsson, Mats; Martinez Pillet, V.; Orozco Suarez, D.; Uitenbroek, Han; Katsukawa, Y. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
    Future ground-based telescopes will expand our capabilities for simultaneous multi-line polarimetric observations in a wide range of wavelengths, from the near-ultraviolet to the near-infrared. This creates a strong demand ...
  • Discovery of an exceptionally bright giant arc at z = 2.369, gravitationally lensed by the Planck cluster PSZ1 G311.65 - 18.48 
    Dahle, Håkon; Aghanim, Nabila; Guennou, L.; Hudelot, P.; Kneissl, R.; Pointecouteau, E.; Beelen, Anita; Bayliss, M; Douspis, M.; Nesvadba, N.; Hempel, A.; Gronke, Max Balthasar; Burenin, R.; Dole, H.; Harrison, Debbie; Mazzotta, P.; Sunyaev, R (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2016)
    As part of an all-sky follow-up of the Planck catalogue of Sunyaev-Zeldovich (SZ) cluster candidates detected in the first 14 months of data, we are observing cluster candidates in the southern sky in the optical imaging ...
  • Discovery of Scattering Polarization in the Hydrogen Lyα Line of the Solar Disk Radiation 
    Kano, R.; Trujillo Bueno, J.; Winebarger, A.; Auchère, F.; Narukage, N.; Ishikawa, R.; Kobayashi, K.; Bando, T.; Katsukawa, Y.; Kubo, M.; Ishikawa, S.; Giono, G.; Hara, H.; Suematsu, Y.; Shimizu, T.; Sakao, T.; Tsuneta, S.; Ichimoto, K.; Goto, M.; Belluzzi, L.; Stepan, Jiri; Asensio Ramos, A.; Manso Sainz, R.; Champey, P.; Cirtain, J.; De Pontieu, Bart Walter; Casini, R.; Carlsson, Mats (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2017)
    There is a thin transition region (TR) in the solar atmosphere where the temperature rises from 10,000 K in the chromosphere to millions of degrees in the corona. Little is known about the mechanisms that dominate this ...
  • Discretisation of the angular two-point correlation function 
    Selmer, Benedicte (Master thesis / Hovedoppgave, 2003)
    Through the two-point correlation function the effects of limited sky coverage and discretisation of data on satellite observations of the cosmic microwave background (CMB) is examined. Analytical expressions for the ...
  • Disentangling flows in the solar transition region 
    Zacharias, Pia; Hansteen, Viggo; Leenaarts, Jorrit; Carlsson, Mats; Gudiksen, Boris Vilhelm (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2018)
    Context: The measured average velocities in solar and stellar spectral lines formed at transition region temperatures have been difficult to interpret. The dominant redshifts observed in the lower transition region naturally ...
  • Dissecting bombs and bursts: Non-LTE inversions of low-atmosphere reconnection in SST and IRIS observations 
    Vissers, Gregal Joan Maria; de la Cruz Rodriguez, Jaime; Libbrecht, Tine; Rouppe van der Voort, Luc; Scharmer, Göran B.; Carlsson, Mats (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)
    Ellerman bombs and UV bursts are transient brightenings that are ubiquitously observed in the lower atmospheres of active and emerging flux regions. As they are believed to pinpoint sites of magnetic reconnection in ...
  • Distinguishing between gravity theories with galaxy peculiar velocity statistics 
    Fauli, Robert Olav (Master thesis / Masteroppgave, 2015)
    The ΛCDM model used in modern cosmology has major theoretical problems. To attempt to solve these many modified gravity theories have been proposed. We calculate velocity statistics (streaming pair-wise velocities and the ...
  • Distinguishing screening mechanisms with environment-dependent velocity statistics 
    Ivarsen, Magnus Fagernes (Master thesis / Masteroppgave, 2016)
  • Diversity in extinction laws of Type Ia supernovae measured between 0.2 and 2 μm 
    Amanullah, R.; Johansson, J.; Goobar, A.; Ferretti, R.; Papodogiannakis, S.; Petrushevska, T.; Brown, P. J.; Cao, Y.; Contreras, C.; Dahle, Håkon; Elias-Rosa, N.; Fynbo, J. P. U.; Gorosabel, J.; Guaita, L.; Hangard, L.; Howell, D. A.; Hsiao, E. Y.; Kankare, E.; Kasliwal, M.; Leloudas, G.; Lundqvist, P.; Mattila, S.; Nugent, P.; Phillips, M. M.; Sandberg, A.; Stanishev, V.; Sullivan, M.; Taddia, F.; Östlin, G.; Asadi, S.; Herrero-Illana, R.; Jensen, J. J.; Karhunen, K.; Lazarevic, S.; Varenius, E.; dos Santos, Paulo Guilherme; Seethapuram Sridhar, S.; Wallström, S. H. J.; Wiegert, J. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2015)
    We present ultraviolet (UV) observations of six nearby Type Ia supernovae (SNe Ia) obtained with the Hubble Space Telescope, three of which were also observed in the near-IR (NIR) with Wide-Field Camera 3. UV observations ...
  • Do we have any hope of detecting scattering between dark energy and baryons through cosmology? 
    Vagnozzi, Sunny; Visinelli, Luca; Mena, Olga; Mota, David (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2020)
    We consider the possibility that dark energy and baryons might scatter off each other. The type of interaction we consider leads to a pure momentum exchange, and does not affect the background evolution of the expansion ...
  • Does a generalized Chaplygin gas correctly describe the cosmological dark sector? 
    vom Marttens, Rodrigo F.; Casarini, Luciano; Zimdahl, Winfried; Hipólito-Ricaldi, William S.; Mota, David (Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2017)
    vom Marttens, R. F., et al. "Does a generalized Chaplygin gas correctly describe the cosmological dark sector?." Physics of the Dark Universe 15 (2017): 114-124. © 2017. This manuscript version is made available under the ...
  • Domain walls coupled to matter: The symmetron example 
    Llinares, Claudio; Pogosian, Levon (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2014)
    We study properties of domain walls in the symmetron model, in which the scalar gravitational degree of freedom decouples from matter in regions of high density and exhibits a spontaneously broken Z2 symmetry at low ...
  • Down-the-barrel observations of a multi-phase quasar outflow at high redshift: VLT/X-shooter spectroscopy of the proximate molecular absorber at z = 2.631 towards SDSS J001514+184212 
    Noterdaeme, Pasquier; Balashev, S.; Krogager, J.-K.; Laursen, Peter; Srianand, R.; Gupta, N.; Petitjean, Patrick; Fynbo, Johan P. U. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
    We present ultraviolet to near infrared spectroscopic observations of the quasar SDSS J001514+184212 and its proximate molecular absorber at z = 2.631. The [O III] emission line of the quasar is composed of a broad (FWHM ...
  • Downflowing umbral flashes as evidence of standing waves in sunspot umbrae 
    Felipe, Tobias; de Jorge Henriques, Vasco Manuel; de la Cruz Rodriguez, Jaime; Socas-Navarro, Hector (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
    Context. Umbral flashes are sudden brightenings commonly visible in the core of some chromospheric lines. Theoretical and numerical modeling suggests that they are produced by the propagation of shock waves. According to ...