Browsing Institutt for teoretisk astrofysikk by Title

Now showing items 457-476 of 1258

  • Fine-scale Explosive Energy Release at Sites of Prospective Magnetic Flux Cancellation in the Core of the Solar Active Region Observed by Hi-C 2.1, IRIS, and SDO 
    Tiwari, Sanjiv K.; Panesar, Navdeep K.; Moore, Ronald L.; De Pontieu, Bart Walter; Winebarger, Amy R.; Golub, Leon; Savage, Sabrina L.; Rachmeler, L. A.; Kobayashi, Ken; Testa, Paola; Warren, Harry P.; Brooks, David H.; Cirtain, Jonathan W.; McKenzie, David E.; Morton, Richard J.; Peter, Hardi; Walsh, Robert W. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)
    The second Hi-C flight (Hi-C 2.1) provided unprecedentedly high spatial and temporal resolution (~250 km, 4.4 s) coronal EUV images of Fe ix/x emission at 172 Å of AR 12712 on 2018 May 29, during 18:56:21–19:01:56 UT. Three ...
  • First analysis of solar structures in 1.21 mm full-disc ALMA image of the Sun 
    Brajša, R.; Sudar, D.; Benz, A. O.; Skokić, I.; Bárta, M.; De Pontieu, Bart Walter; Kim, S.; Kobelski, A.; Kuhar, M.; Shimojo, M.; Wedemeyer, Sven; White, S.; Yagoubov, P.; Yan, Y. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2018)
    Context: Various solar features can be seen in emission or absorption on maps of the Sun in the millimetre and submillimetre wavelength range. The recently installed Atacama Large Millimetre/submillimetre Array (ALMA) is ...
  • A First Comparison of Millimeter Continuum and Mg II Ultraviolet Line Emission from the Solar Chromosphere 
    Bastian, T. S.; Chintzoglou, G.; De Pontieu, Bart Walter; Shimojo, M.; Schmit, D.; Leenaarts, Jorrit; Loukitcheva, M. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2017)
    We present joint observations of the Sun by the Atacama Large Millimeter/submillimeter Array (ALMA) and the Interface Region Imaging Spectrograph (IRIS). Both millimeter/submillimeter-λ continuum emission and ultraviolet ...
  • First detection of AlF line emission towards M-type AGB stars 
    Saberi, Maryam; Khouri, T.; Velilla-Prieto, L.; Fonfría, J.P.; Vlemmings, W.H.T.; Wedemeyer, Sven (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2022)
    The nucleosynthesis production of fluorine (F) is still a matter of debate. Asymptotic giant branch (AGB) stars are one of the main candidates for F production. However, their contribution to the total F budget is not fully ...
  • First direct observation of a torsional Alfvén oscillation at coronal heights 
    Kohutova, Petra; Verwichte, Erwin; Froment, Clara (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2020)
    Context. Torsional Alfvén waves are promising candidates for the transport of energy across different layers of the solar atmosphere. They have been predicted theoretically for decades. Previous detections of Alfvén waves ...
  • First high resolution interferometric observation of a solar prominence with ALMA 
    Labrosse, Nicolas; Rodger, Andrew S.; Radziszewski, Krzysztof; Rudawy, Paweł; Antolin, Patrick; Fletcher, Lyndsay; Levens, Peter J.; Peat, Aaron W.; Schmieder, Birgitte; Simões, Paulo J.A. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2022)
    ABSTRACT We present the first observation of a solar prominence at 84 − 116 GHz using the high resolution interferometric imaging of ALMA. Simultaneous observations in Hα from Białkaw Observatory and with SDO/AIA ...
  • First high-resolution look at the quiet Sun with ALMA at 3mm 
    Nindos, A.; Alissandrakis, C. E.; Bastian, T. S.; Patsourakos, S.; De Pontieu, Bart Walter; Warren, H.; Ayres, T.; Hudson, H. S.; Shimizu, T.; Vial, J.-C.; Wedemeyer, Sven; Yurchyshyn, V. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2018)
    We present an overview of high-resolution quiet Sun observations, from disk center to the limb, obtained with the Atacama Large millimeter and sub-millimeter Array (ALMA) at 3 mm. Seven quiet-Sun regions were observed at ...
  • First High-Resolution Spectroscopic Observations of an Erupting Prominence within a Coronal Mass Ejection by the Interface Region Imaging Spectrograph (IRIS) 
    Liu, W.; De Pontieu, Bart Walter; Vial, J.-C.; Title, Alan M.; Carlsson, Mats; Uitenbroek, Han; Okamoto, T. J.; Berger, Thomas E.; Antolin, Patrick (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2015)
    Spectroscopic observations of prominence eruptions associated with coronal mass ejections (CMEs), although relatively rare, can provide valuable plasma and three-dimensional geometry diagnostics. We report the first ...
  • First observations from the SPICE EUV spectrometer on Solar Orbiter 
    Fludra, Andrzej; Caldwell, M.; Giunta, A.; Grundy, T.; Guest, S.; Leeks, S.; Sidher, S.; Auchère, Frédéric; Carlsson, Mats; Hassler, D.; Peter, Hardi; Aznar Cuadrado, R.; Buchlin, Éric; Caminade, S.; DeForest, C.; Fredvik, Terje; Haberreiter, Margit; Harra, Louise K.; Janvier, M.; Kucera, T.; Müller, Daniel; Parenti, S.; Schmutz, W.; Schüle, U.; Solanki, Sami K.; Teriaca, L.; Thompson, W. T.; Tustain, S.; Williams, D.; Young, P. R.; Chitta, Lakshmi Pradeep (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
    Aims. We present first science observations taken during the commissioning activities of the Spectral Imaging of the Coronal Environment (SPICE) instrument on the ESA/NASA Solar Orbiter mission. SPICE is a high-resolution ...
  • First perihelion of EUI on the Solar Orbiter mission 
    Berghmans, D.; Antolin, Patrick; Auchère, F.; Aznar Cuadrado, R.; Barczynski, K.; Chitta, L.P.; Gissot, S.; Harra, L.; Huang, Z.; Janvier, M.; Kraaikamp, E.; Long, D.M.; Mandal, S.; Mierla, M.; Parenti, S.; Peter, H.; Rodriguez, L.; Schühle, U.; Smith, P.J.; Solanki, S.K.; Stegen, K.; Teriaca, L.; Verbeeck, C.; West, M.J.; Zhukov, A.N.; Appourchaux, T.; Aulanier, Guillaume; Buchlin, E.; Delmotte, F.; Gilles, J.M.; Haberreiter, M.; Halain, J.-P.; Heerlein, K.; Hochedez, J.-F.; Gyo, M.; Poedts, S.; Renotte, E.; Rochus, P. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2023)
    Context. The Extreme Ultraviolet Imager (EUI) on board Solar Orbiter consists of three telescopes: the two High Resolution Imagers, in EUV (HRI EUV ) and in Lyman- α (HRI Lya ), and the Full Sun Imager (FSI). Solar Orbiter/EUI ...
  • First Spectral Analysis of a Solar Plasma Eruption Using ALMA 
    Rodger, Andrew S.; Labrosse, Nicolas; Wedemeyer, Sven; Szydlarski, Mikolaj Marcin; Simões, Paulo J. A.; Fletcher, Lyndsay (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)
    The aim of this study is to demonstrate how the logarithmic millimeter continuum gradient observed using the Atacama Large Millimeter/submillimeter Array (ALMA) may be used to estimate optical thickness in the solar ...
  • Flare kernels may be smaller than you think: modelling the radiative response of chromospheric plasma adjacent to a solar flare 
    Osborne, Christopher M. J.; Fletcher, Lyndsay (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2022)
    ABSTRACT Numerical models of solar flares typically focus on the behaviour of directly heated flare models, adopting magnetic-field-aligned, plane-parallel methodologies. With high spatial- and spectral-resolution ...
  • The forcing and climate response of black carbon aerosols 
    Sand, Maria (Doctoral thesis / Doktoravhandling, 2014)
  • Forecast constraints on anisotropic stress in dark energy using gravitational waves 
    Yang, Weiqiang; Pan, Supriya; Mota, David; Du, Minghui (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2020)
    It is always interesting to investigate how well can a future experiment perform with respect to others (present or future ones). Cosmology is really an exciting field where a lot of puzzles are still unknown. In this ...
  • Foreground separation and constraints on primordial gravitational waves with the PICO space mission 
    Aurvik, Ragnhild; Remazeilles, Mathieu; Belkner, Sebastian; Carron, Julien; Delabrouille, Jacques; Eriksen, Hans Kristian Kamfjord; Flauger, Raphael; Fuskeland, Unni; Galloway, Mathew; Górski, Krzysztof M.; Hanany, Shaul; Hensley, Brandon S.; Hill, J. Colin; Lawrence, Charles R.; Pryke, Clement; van Engelen, Alexander; Wehus, Ingunn Kathrine (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2023)
    PICO is a concept for a NASA probe-scale mission aiming to detect or constrain the tensor to scalar ratio r, a parameter that quantifies the amplitude of inflationary gravity waves. We carry out map-based component separation ...
  • Formation and heating of chromospheric fibrils in a radiation-MHD simulation 
    Druett, Malcolm K.; Leenarts, Jorrit; Carlsson, Mats; Szydlarski, Mikolaj (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2022)
    Aims. We examine the movements of mass elements within dense fibrils using passive tracer particles (corks) in order to understand the creation and destruction processes of fibrils. Methods. Simulated fibrils were ...
  • Formation of an observed eruptive flux rope above the torus instability threshold through tether-cutting magnetic reconnection 
    Prasad, Avijeet; Kumar, S.; Sterling, A.C.; Moore, R.L.; Aulanier, Guillaume; Bhattacharyya, R.; Hu, Q. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2023)
    Context. Erupting magnetic flux ropes (MFRs) are believed to play a crucial role in producing solar flares. However, the formation of erupting MFRs in complex coronal magnetic configurations and the role of their subsequent ...
  • Formation of coronal rain triggered by impulsive heating associated with magnetic reconnection 
    Kohutova, Petra; Verwichte, Erwin; Froment, Clara (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)
    Context. Coronal rain consists of cool plasma condensations formed in coronal loops as a result of thermal instability. The standard models of coronal rain formation assume that the heating is quasi-steady and localised ...
  • Formation of Hϵ in the solar atmosphere 
    Krikova, Kilian; Pereira, Tiago; Rouppe van der Voort, Luc (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2023)
    Context. In the solar spectrum, the Balmer series line H ε is a weak blend on the wing of Ca  II H. Recent high-resolution H ε spectroheliograms reveal a reversed granulation pattern and in some cases, even unique structures. ...
  • THE FORMATION OF IRIS DIAGNOSTICS. I. A QUINTESSENTIAL MODEL ATOM OF Mg II AND GENERAL FORMATION PROPERTIES OF THE Mg II h&k LINES 
    Leenaarts, Jorrit; Pereira, Tiago Mendes Domingos; Carlsson, Mats; Uitenbroek, H.; De Pontieu, Bart Walter (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2013)
    NASA's Interface Region Imaging Spectrograph (IRIS) space mission will study how the solar atmosphere is energized. IRIS contains an imaging spectrograph that covers the Mg II h&k lines as well as a slit-jaw imager centered ...