Browsing Institutt for teoretisk astrofysikk by Author "Nóbrega Siverio, Daniel Elias"

Now showing items 1-18 of 18

  • A 2D Model for Coronal Bright Points: Association with Spicules, UV Bursts, Surges, and EUV Coronal Jets 
    Nóbrega Siverio, Daniel Elias; Moreno-Insertis, F. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2022)
    Coronal bright points (CBPs) are ubiquitous structures in the solar atmosphere composed of hot small-scale loops observed in extreme-ultraviolet (EUV) or X-rays in the quiet Sun and coronal holes. They are key elements to ...
  • A comparative study of resistivity models for simulations of magnetic reconnection in the solar atmosphere 
    Færder, Øystein Håvard; Nóbrega Siverio, Daniel Elias; Carlsson, Mats (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2023)
    Context. Magnetic reconnection is a fundamental mechanism in astrophysics. A common challenge in mimicking this process numerically in particular for the Sun is that the solar electrical resistivity is small compared to ...
  • A comparative study of resistivity models for simulations of magnetic reconnection in the solar atmosphere. II. Plasmoid formation 
    Færder, Øystein Håvard; Nóbrega Siverio, Daniel Elias; Carlsson, Mats (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2024)
    Context. Plasmoid-mediated reconnection plays a fundamental role in different solar atmospheric phenomena. Numerical reproduction of this process is therefore essential for developing robust solar models. Aims. Our goal ...
  • A New View of the Solar Interface Region from the Interface Region Imaging Spectrograph (IRIS) 
    De Pontieu, Bart Walter; Polito, Vanessa; Hansteen, Viggo Haraldson; Testa, Paola; Reeves, Katharine K.; Antolin, Patrick; Nóbrega Siverio, Daniel Elias; Kowalski, Adam F.; Martinez-Sykora, Juan; Carlsson, Mats; McIntosh, Scott W.; Liu, Wei; Daw, Adrian N.; Kankelborg, Charles C. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
    Abstract The Interface Region Imaging Spectrograph (IRIS) has been obtaining near- and far-ultraviolet images and spectra of the solar atmosphere since July 2013. IRIS is the highest resolution observatory to provide ...
  • Ambipolar diffusion in the Bifrost code 
    Nóbrega Siverio, Daniel Elias; Martinez-Sykora, Juan; Moreno-Insertis, Fernando; Carlsson, Mats (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2020)
    Context. Ambipolar diffusion is a physical mechanism related to the drift between charged and neutral particles in a partially ionized plasma that is key to many different astrophysical systems. However, understanding its ...
  • Ambipolar diffusion: Self-similar solutions and MHD code testing: Cylindrical symmetry 
    Moreno-Insertis, F.; Nóbrega Siverio, Daniel Elias; Priest, E.R.; Hood, A.W. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2022)
    Context. Ambipolar diffusion is a process occurring in partially ionised astrophysical systems that imparts a complicated mathematical and physical nature to Ohm’s law. The numerical codes that solve the magnetohydrodynamic ...
  • Case study of multi-temperature coronal jets for emerging flux MHD models 
    Joshi, Reetika; Chandra, Ramesh; Schmieder, Brigitte; Moreno-Insertis, Fernando; Aulanier, Guillaume; Nóbrega Siverio, Daniel Elias; Devi, Pooja (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2020)
    Context. Hot coronal jets are a basic observed feature of the solar atmosphere whose physical origin is still actively debated. Aims. We study six recurrent jets that occurred in active region NOAA 12644 on April 4, 2017. ...
  • Deciphering Solar Coronal Heating: Energizing Small-scale Loops through Surface Convection 
    Nóbrega Siverio, Daniel Elias; Moreno-Insertis, F.; Galsgaard, K.; Krikova, Kilian; Rouppe van der Voort, Luc; Joshi, Reetika; Madjarska, M.S. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2023)
    Abstract The solar atmosphere is filled with clusters of hot small-scale loops commonly known as coronal bright points (CBPs). These ubiquitous structures stand out in the Sun by their strong X-ray and/or ...
  • Ellerman bombs and UV bursts: reconnection at different atmospheric layers 
    Ortiz, Ada; Hansteen, Viggo; Nóbrega Siverio, Daniel Elias; Rouppe van der Voort, Luc (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2020)
    The emergence of magnetic flux through the photosphere and into the outer solar atmosphere produces, amongst other dynamical phenomena, Ellerman bombs (EBs), which are observed in the wings of Hα and are due to magnetic ...
  • Ellerman bombs and UV bursts: reconnection at different atmospheric layers 
    Ortiz, Ada; Hansteen, Viggo; Nóbrega Siverio, Daniel Elias; van der Voort, Luc Rouppe (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2020)
    The emergence of magnetic flux through the photosphere and into the outer solar atmosphere produces, amongst other dynamical phenomena, Ellerman bombs (EBs), which are observed in the wings of Hα and are due to magnetic ...
  • High-resolution observations of the solar photosphere, chromosphere, and transition region: A database of coordinated IRIS and SST observations 
    Rouppe van der Voort, Luc; De Pontieu, Bart Walter; Carlsson, Mats; de la Cruz Rodriguez, Jaime; Bose, Souvik; Chintzoglou, Georgios; Drews, Ainar; Froment, Clara; Gošić, Milan; Graham, David R.; Hansteen, Viggo; de Jorge Henriques, Vasco Manuel; Jafarzadeh, Shahin; Joshi, Jayant; Kleint, Lucia; Kohutova, Petra; Leifsen, Torben; Martinez-Sykora, Juan; Nóbrega Siverio, Daniel Elias; Ortiz, Ada; Mendes Domingos Pereira, Tiago; Popovas, Andrius; Quintero Noda, Carlos; Sainz Dalda, Alberto; Scharmer, Göran B.; Schmit, Donald; Scullion, Eamon; Skogsrud, Håkon; Szydlarski, Mikolaj Marcin; Timmons, R.; Vissers, Gregal Joan Maria; Woods, M. M.; Zacharias, Pia (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2020)
    NASA’s Interface Region Imaging Spectrograph (IRIS) provides high-resolution observations of the solar atmosphere through ultraviolet spectroscopy and imaging. Since the launch of IRIS in June 2013, we have conducted ...
  • Nonequilibrium ionization and ambipolar diffusion in solar magnetic flux emergence processes 
    Nóbrega Siverio, Daniel Elias; Moreno-Insertis, Fernando; Martinez-Sykora, Juan; Carlsson, Mats; Szydlarski, Mikolaj Marcin (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)
    Context. Magnetic flux emergence from the solar interior has been shown to be a key mechanism for unleashing a wide variety of phenomena. However, there are still open questions concerning the rise of the magnetized plasma ...
  • Probing the Physics of the Solar Atmosphere with the Multi-slit Solar Explorer (MUSE). I. Coronal Heating 
    De Pontieu, Bart Walter; Testa, Paola; Martinez-Sykora, Juan; Antolin, Patrick; Karampelas, Konstantinos; Hansteen, Viggo Haraldson; Rempel, Matthias; Cheung, Mark C. M.; Reale, Fabio; Danilovic, Sanja; Pagano, Paolo; Polito, Vanessa; de Moortel, Ineke; Nóbrega Siverio, Daniel Elias; Van Doorsselaere, Tom; Petralia, Antonino; Asgari-Targhi, Mahboubeh; Boerner, Paul; Carlsson, Mats; Chintzoglou, Georgios; Daw, Adrian; DeLuca, Edward; Golub, Leon; Matsumoto, Takuma; Ugarte-Urra, Ignacio; McIntosh, Scott W. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2022)
  • Probing the Physics of the Solar Atmosphere with the Multi-slit Solar Explorer (MUSE). II. Flares and Eruptions 
    Cheung, Mark C. M.; Martinez-Sykora, Juan; Testa, Paola; De Pontieu, Bart Walter; Chintzoglou, Georgios; Rempel, Matthias; Polito, Vanessa; Kerr, Graham S.; Reeves, Katharine K.; Fletcher, Lyndsay; Jin, Meng; Nóbrega Siverio, Daniel Elias; Danilovic, Sanja; Antolin, Patrick; Allred, Joel; Hansteen, Viggo Haraldson; Ugarte-Urra, Ignacio; DeLuca, Edward; Longcope, Dana; Takasao, Shinsuke; DeRosa, Marc L.; Boerner, Paul; Jaeggli, Sarah; Nitta, Nariaki V.; Daw, Adrian; Carlsson, Mats; Golub, Leon (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2022)
    Current state-of-the-art spectrographs cannot resolve the fundamental spatial (subarcseconds) and temporal (less than a few tens of seconds) scales of the coronal dynamics of solar flares and eruptive phenomena. The ...
  • Signatures of Magnetic Reconnection at the Footpoints of Fan-shaped Jets on a Light Bridge Driven by Photospheric Convective Motions 
    Bai, Xianyong; Socas-Navarro, Hector; Nóbrega Siverio, Daniel Elias; Su, Jiangtao; Deng, Yuanyong; Li, Dong; Cao, Wenda; Ji, Kaifan (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)
    Dynamical jets are generally found on light bridges (LBs), which are key to studying sunspot decay. So far, their formation mechanism is not fully understood. In this paper, we used state-of-the-art observations from the ...
  • Solar surges related to UV bursts. Characterization through k-means, inversions, and density diagnostics 
    Nóbrega Siverio, Daniel Elias; Guglielmino, Salvo L.; Sainz Dalda, Alberto (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
    Context. Surges are cool and dense ejections typically observed in chromospheric lines and closely related to other solar phenomena such as UV bursts or coronal jets. Even though surges have been observed for decades now, ...
  • The Chromosphere Underneath a Coronal Bright Point 
    Bose, Souvik; Nóbrega Siverio, Daniel Elias; De Pontieu, Bart Walter; Rouppe van der Voort, Luc (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2023)
    Abstract Coronal bright points (CBPs) are sets of small-scale coronal loops, connecting opposite magnetic polarities, primarily characterized by their enhanced extreme-ultraviolet (EUV) and X-ray emission. Being ...
  • The chromospheric component of coronal bright points. Coronal and chromospheric responses to magnetic-flux emergence 
    Madjarska, Maria S.; Chae, Jongchul; Moreno-Insertis, Fernando; Hou, Zhenyong; Nóbrega Siverio, Daniel Elias; Kwak, Hannah; Galsgaard, Klaus; Cho, Kyuhyoun (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
    Context. We investigate the chromospheric counterpart of small-scale coronal loops constituting a coronal bright point (CBP) and its response to a photospheric magnetic-flux increase accompanied by co-temporal CBP heating. ...