Browsing Institutt for teoretisk astrofysikk by Author "Uitenbroek, Han"

Now showing items 1-14 of 14

  • DeSIRe: Departure coefficient aided Stokes Inversion based on Response functions 
    Ruiz Cobo, Basilio; Quintero Noda, Carlos; Gafeira, R.; Uitenbroek, Han; Orozco Suárez, David; Páez Mañá, E. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2022)
    Future ground-based telescopes, such as the 4-metre class facilities DKIST and EST, will dramatically improve on current capabilities for simultaneous multi-line polarimetric observations in a wide range of wavelength ...
  • 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 ...
  • 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 ...
  • THE FORMATION OF IRIS DIAGNOSTICS. III. NEAR-ULTRAVIOLET SPECTRA AND IMAGES 
    Pereira, Tiago Mendes Domingos; Leenaarts, Jorrit; De Pontieu, Bart Walter; Carlsson, Mats; Uitenbroek, Han (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2013)
    The Mg II h&k lines are the prime chromospheric diagnostics of NASA's Interface Region Imaging Spectrograph (IRIS). In the previous papers of this series, we used a realistic three-dimensional radiative magnetohydrodynamics ...
  • Hydrogen Balmer Line Broadening in Solar and Stellar Flares 
    Kowalski, Adam F.; Allred, Joel C.; Uitenbroek, Han; Tremblay, Pier-Emmanuel; Brown, Stephen; Carlsson, Mats; Osten, R. A.; Wisniewski, John P.; Hawley, Suzanne L. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2017)
    The broadening of the hydrogen lines during flares is thought to result from increased charge (electron, proton) density in the flare chromosphere. However, disagreements between theory and modeling prescriptions have ...
  • Indication of the Hanle Effect by Comparing the Scattering Polarization Observed by CLASP in the Lyα and Si III 120.65 nm Lines 
    Ishikawa, R.; Trujillo Bueno, J.; Uitenbroek, Han; Kubo, M.; Tsuneta, S.; Goto, M.; Kano, R.; Narukage, N.; Bando, T.; Katsukawa, Y.; Ishikawa, S.; Giono, G.; Suematsu, Y.; Hara, H.; Shimizu, T.; Sakao, T.; Winebarger, A.; Kobayashi, K.; Cirtain, J.; Champey, P.; Auchère, F.; Stepan, Jiri; Belluzzi, L.; Asensio Ramos, A.; Manso Sainz, R.; De Pontieu, Bart Walter; Ichimoto, K.; Carlsson, Mats; Casini, R. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2017)
    The Chromospheric Lyman-Alpha Spectro-Polarimeter is a sounding rocket experiment that has provided the first successful measurement of the linear polarization produced by scattering processes in the hydrogen Lyα line ...
  • Machine learning initialization to accelerate Stokes profile inversions 
    Gafeira, Ricardo; Orozco Suarez, D.; Milić, Ivan; Quintero Noda, Carlos; Ruiz Cobo, Basilio; Uitenbroek, Han (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
    Context. At present, an exponential growth in scientific data from current and upcoming solar observatories is expected. Most of the data consist of high spatial and temporal resolution cubes of Stokes profiles taken in ...
  • Modeling Mg II h, k and Triplet Lines at Solar Flare Ribbons 
    Zhu, Yingjie; Kowalski, Adam F.; Tian, Hui; Uitenbroek, Han; Carlsson, Mats; Allred, Joel C. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)
    Observations from the Interface Region Imaging Spectrograph often reveal significantly broadened and non-reversed profiles of the Mg ii h, k and triplet lines at flare ribbons. To understand the formation of these optically ...
  • RESONANT ABSORPTION OF TRANSVERSE OSCILLATIONS AND ASSOCIATED HEATING IN A SOLAR PROMINENCE. I. OBSERVATIONAL ASPECTS 
    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. ...
  • RH 1.5D: A massively parallel code for multi-level radiative transfer with partial frequency redistribution and Zeeman polarisation 
    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 ...
  • Solar polarimetry through the KI lines at 770 nm 
    Quintero Noda, C.; Uitenbroek, Han; Katsukawa, Y.; Shimizu, T.; Oba, T.; Carlsson, Mats; Orozco Suarez, D.; Ruiz Cobo, B.; Kubo, M.; Anan, T.; Ichimoto, K.; Suematsu, Y. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2017)
    We characterize the K i D1 & D2 lines in order to determine whether they could complement the 850 nm window, containing the Ca ii infrared triplet lines and several Zeeman sensitive photospheric lines, that was studied ...
  • Study of the polarization produced by the Zeeman effect in the solar Mg I b lines 
    Quintero Noda, C.; Uitenbroek, Han; Carlsson, Mats; Orozco Suarez, D.; Katsukawa, Y.; Shimizu, T.; Ruiz Cobo, B.; Kubo, M.; Oba, T.; Kawabata, Y.; Hasegawa, T.; Ichimoto, K.; Anan, T.; Suematsu, Y. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2018)
    The next generation of solar observatories aim to understand the magnetism of the solar chromosphere. Therefore, it is crucial to understand the polarimetric signatures of chromospheric spectral lines. For this purpose, ...
  • The Atmospheric Response to High Nonthermal Electron-beam Fluxes in Solar Flares. II. Hydrogen-broadening Predictions for Solar Flare Observations with the Daniel K. Inouye Solar Telescope 
    Kowalski, Adam F.; Allred, Joel C.; Carlsson, Mats; Kerr, Graham S.; Tremblay, Pier-Emmanuel; Namekata, Kosuke; Kuridze, David; Uitenbroek, Han (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2022)
    Redshifted components of chromospheric emission lines in the hard X-ray impulsive phase of solar flares have recently been studied through their 30 s evolution with the high resolution of the Interface Region Imaging ...
  • The Propagation of Coherent Waves Across Multiple Solar Magnetic Pores 
    Grant, Samuel D. T.; Jess, D.B.; Stangalini, M.; Jafarzadeh, Shahin; Fedun, V.; Verth, G.; Keys, P.H.; Rajaguru, S.P.; Uitenbroek, Han; Macbride, C.D.; Bate, W.; Gilchrist-Millar, C.A. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2022)
    Abstract Solar pores are efficient magnetic conduits for propagating magnetohydrodynamic wave energy into the outer regions of the solar atmosphere. Pore observations often contain isolated and/or unconnected ...