Browsing Institutt for teoretisk astrofysikk by Title

Now showing items 343-362 of 1278

  • 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 ...
  • Download by parachute: retrieval of assets from high altitude balloons 
    Sirks, Ellen L.; Clark, P.; Massey, Richard J.; Benton, S. J.; Brown, A. M.; Damaren, Christopher J.; Eifler, Tim; Fraisse, Aurélien A.; Frenk, Carlos; Funk, M.; Galloway, Mathew; Gill, Ajay; Hartley, John W.; Holder, Bradley; Huff, Eric M.; Jauzac, Mathilde; Jones, William C.; Lagattuta, David; Leung, Jason S.-Y.; Li, L.; Luu, Thuy Vy T.; McCleary, Jacqueline; Netterfield, Calvin Barth; Redmond, S.; Rhodes, Jason D.; Romualdez, L. Javier; Schmoll, Jürgen; Shaaban, Mohamed M.; Tam, Sut-Ieng (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2020)
    We present a publicly-available toolkit of flight-proven hardware and software to retrieve 5 TB of data or small physical samples from a stratospheric balloon platform. Before launch, a capsule is attached to the balloon, ...
  • Dramatic Changes in the Observed Velocity of the Accretion Disk Wind in MCG-03-58-007 Are Revealed by XMM-Newton and NuSTAR 
    Braito, Valentina; Reeves, J.N.; Matzeu, Gabriele A.; Severgnini, Paola; Ballo, Lucia; Cicone, Claudia; Ceca, R. Della; Giustini, M.; Sirressi, Mattia (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2022)
    Past X-ray observations of the nearby Seyfert 2 MCG-03-58-007 revealed the presence of a powerful and highly variable disk wind, where two possible phases outflowing with vout1/c ∼ −0.07 and vout2/c ∼ −0.2 were observed. ...
  • Dwarf AGNs from Optical Variability for the Origins of Seeds (DAVOS): insights from the dark energy survey deep fields 
    Burke, Colin J.; Liu, Xin; Shen, Yue; Phadke, Kedar A.; Yang, Qian; Hartley, William G.; Harrison, Ian; Palmese, Antonella; Hengxiao, Guo; Zhang, Kaiwen; Kron, Richard; Turner, David J.; Giles, Paul A.; Lidman, Christopher; Chen, Yu-Ching; Gruendl, Robert A.; Choi, Ami; Amon, Alexandra; Sheldon, Erin; Aguena, M.; Allam, Sahar; Andrade-Oliveira, Felipe; Bacon, D.; Bertin, E.; Brooks, D.; Carnero Rosell, Aurelio; Carrasco Kind, Matias; Carretero, J.; Conselice, Christopher; Costanzi, M.; da Costa, Luiz N.; Pereira, Maria Elidaiana da Silva; Davis, Tamara M.; De Vicente, J.; Desai, S.; Diehl, Herman T.; Everett, S.; Ferrero, Ismael; Flaugher, B.; García-Bellido, J.; Gaztañaga, Enrique; Gruen, D.; Gschwend, J.; Gutierrez, G.; Hinton, Samuel R.; Hollowood, Devon L.; Honscheid, K.; Hoyle, B.; James, D. J.; Kuehn, K.; Maia, M. A. G.; Marshall, Jennifer L.; Menanteau, F.; Miquel, R.; Morgan, R.; Paz-Chinchón, Francisco; Pieres, A.; Plazas Malagón, Andrés A.; Reil, K.; Romer, A. K.; Sanchez, E.; Schubnell, M.; Serrano, S.; Sevilla-Noarbe, Ignacio; Smith, Mathew; Suchyta, E.; Tarle, G.; Thomas, D.; To, Chun-Hao; Varga, Tamas Norbert; Wilkinson, R. D. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2022)
    We present a sample of 706, z < 1.5 active galactic nuclei (AGNs) selected from optical photometric variability in three of the Dark Energy Survey (DES) deep fields (E2, C3, and X3) over an area of 4.64 deg2. We construct ...
  • Dynamic Loops in a Solar Active Region 
    Emblemsvåg, Geir (Master thesis / Hovedoppgave, 2007)
  • Dynamic properties along the neutral line of a delta spot inferred from high-resolution observations 
    Cristaldi, A.; Guglielmino, S. L.; Zuccarello, F.; Romano, P.; Falco, M.; Rouppe, Van Der Voort Luc; de la Cruz Rodriguez, Jaime; Ermolli, I.; Criscuoli, S. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2014)
    Delta (δ) spots are complex magnetic configurations of sunspots characterized by umbrae of opposite polarity sharing a common penumbra. In order to investigate the fine structure of the region separating the two magnetic ...
  • Dynamical friction on hot bodies in gaseous, opaque media, and application to embedded protoplanets 
    Masset, F.S.; Velasco Romero, D.A.; Eklund, Lars Henrik (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2018)
    A massive and luminous perturber moving across an opaque gas is subjected to a force different from the gravitational friction that it would experience if it were cold. The heat released by the perturber diffuses in the ...
  • Dynamics of fine structure in the atmosphere of solar active regions 
    Vissers, Gregal Joan Maria (Doctoral thesis / Doktoravhandling, 2013)
    This thesis presents an observational study of the dynamics of fine structure in the (mostly lower) atmosphere of solar active regions. The considered phenomena – Ellerman bombs, flocculent flows and coronal rain – are ...
  • Dynamics of internetwork chromospheric fibrils: Basic properties and magnetohydrodynamic kink waves 
    Mooroogen, K.; Morton, R. J.; de Jorge Henriques, Vasco Manuel (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2017)
    Aims. Current observational instruments are now providing data with the necessary temporal and spatial cadences required to examine highly dynamic, fine-scale magnetic structures in the solar atmosphere. Using the spectroscopic ...
  • Dynamics of Large-Scale Solar Flows 
    Hotta, Hideyuki; Bekki, Yuto; Gizon, Laurent; Noraz, Quentin Jean Francois Alain; Rast, Mark (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2023)
    Abstract The Sun’s axisymmetric large-scale flows, differential rotation and meridional circulation, are thought to be maintained by the influence of rotation on the thermal-convective motions in the solar convection zone. ...
  • The dynamics of the Local Group as a probe of dark energy and modified gravity 
    Carlesi, Edoardo; Mota, David; Winther, Hans Arnold (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2017)
    In this work, we study the dynamics of the Local Group (LG) within the context of cosmological models beyond General Relativity (GR). Using observable kinematic quantities to identify candidate pairs, we build up samples ...
  • Early cosmology constrained 
    Verde, Licia; Bellini, Emilio; Pigozzo, Cassio; Heavens, Alan F.; Jimenez, Raul (Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2017)
    We investigate our knowledge of early universe cosmology by exploring how much additional energy density can be placed in different components beyond those in the ΛCDM model. To do this we use a method to separate early- ...
  • Early Science with the Next Generation Transit Survey 
    Hodzic, Vedad (Master thesis / Masteroppgave, 2017)
    The Next Generation Transit Survey (NGTS) is an ongoing wide-field exoplanet transit survey at ESO Paranal Observatory, Chile. It is searching for Neptune and super-Earth size planets around nearby stars using 12 robotic ...
  • The Effect of Corner Modes in the Initial Conditions of Cosmological Simulations 
    Falck, Bridget Lynn; McCullagh, N.; Neyrinck, M. C.; Wang, J.; Szalay, A. S. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2017)
    © 2017. The American Astronomical Society. All rights reserved.
  • Effect of coronal loop structure on wave heating through phase mixing 
    Pagano, P.; de Moortel, Ineke; Morton, R. J. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2020)
    Context. The mechanism(s) behind coronal heating still elude(s) direct observation and modelling of viable theoretical processes and the subsequent effect on coronal structures is one of the key tools available to assess ...
  • The effect of galactic contamination on the largest scales in cosmic background radiation maps 
    Tangvald, Anders (Master thesis / Masteroppgave, 2008)
    Observations of the Cosmic Microwave Background is impaired by other astrophysical sources that also radiate in the microwave spectrum. These other, non-CMB sources are known as foregrounds. In this thesis, three different ...
  • THE EFFECT OF ISOTOPIC SPLITTING ON THE BISECTOR AND INVERSIONS OF THE SOLAR Ca II 854.2 nm LINE 
    Leenaarts, Jorrit; de la Cruz Rodriguez, Jaime; Kochukhov, Oleg; Carlsson, Mats (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2014)
    The Ca II 854.2 nm spectral line is a common diagnostic of the solar chromosphere. The average line profile shows an asymmetric core, and its bisector shows a characteristic inverse-C shape. The line actually consists of ...
  • Effect of the cubic torus topology on cosmological perturbations 
    Eingorn, Maxim; Canay, Ezgi; Metcalf, Jacob M.; Brilenkov, Maksym; Zhuk, Alexander (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
    We study the effect of the cubic torus topology of the Universe on scalar cosmological perturbations which define the gravitational potential. We obtain three alternative forms of the solution for both the gravitational ...
  • Effects of anisotropic stress in interacting dark matter – dark energy scenarios 
    Yang, Weiqiang; Pan, Supriya; Xu, Lixin; Mota, David (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2018)
    We study a novel interacting dark energy − dark matter scenario where the anisotropic stress of the large-scale inhomogeneities is considered. The dark energy has a constant equation of state and the interaction model ...
  • Effects of neutrino mass hierarchies on dynamical dark energy models 
    Yang, Weiqiang; Nunes, Rafael C.; Pan, Supriya; Mota, David (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2017)
    © 2017 American Physical Society