Sven Wedemeyer

Førsteamanuensis - Rosseland senter for solfysikk

English version of this page

E-post sven.wedemeyer@astro.uio.no

Telefon +47 22856520

Rom 203

Brukernavn

Besøksadresse Sem Sælands vei 13 Svein Rosselands hus 0371 OSLO

Postadresse Postboks 1029 0315 Oslo

Pressebilde Last ned visittkort

ORCID 0000-0002-5006-7540

Primary research fields

Solar and stellar physics with additional interests in extra-solar planets. Most of my individual projects combine realistic numerical simulations and space-borne and ground-based observations.

Current main positions and functions

Associate Professor (permanent staff) and among the PIs of the Rosseland Centre for Solar Physics (RoCS, since 2017), a centre of excellence funded by the Research Council of Norway
PI of the EMISSA project (funded by the Research Council of Norway, 2019-2023)
PI of the ESO-funded ALMA Development Study High-Cadence Imaging of the Sun (since 2018)
Vice president and board member of the European Solar Physics Division (ESPD) of the European Physical Society (EPS, since 2021)
Member of the European Scientific Advisory Committee (ESAC) for ALMA (ESO, since 2017)
Norwegian representative at the Observing Programme Committee (OPC) of the Nordic Optical Telescope (NOT)
Initiator and co-ordinator of the SSALMON research network with more than 80 researchers (since 2014)
External staff member of the ALMA Regional Center at Ondrejoy, Czech Republic

Current major research activities

Solar/Stellar Science with the Atacama Large Millimeter Array

As a legacy of the ERC-funded SolarALMA project, a combination of simulations and ALMA observations are used for detailed studies of the small-scale structure, dynamics and heating of the solar chromosphere.
The ESO-funded ALMA Development Study aims at improving and developing solar observing modes.
The EMISSA project (funded by the Research Council of Norway) addresses solar and stellar activity as observed with ALMA, supported by numerical simulation.
International team for developing solar observing modes for ALMA, as combination of the previous project "Advanced Solar Observing Techniques" within the North American Study Plan for Development Upgrades of the ALMA (PI: T. Bastian, NRAO, USA) and the project "Solar Research with ALMA" carried out at the Czech node of the European ALMA Regional Center (EU ARC at Ondrejov, Czech Republic) in the frame of the ESO program "Enhancement of ALMA Capabilities/EoC" (PI: R. Brajsa, Hvar Observatory, Croatia).
SSALMON - The Solar Simulations for the Atacama Large Millimeter Observatory Network (since 2014).
Member of the AtLAST consortium / the design study AtLAST - The Atacama Large Aperture Submm Telescope

Small-scale dynamics and energy balance of the solar atmosphere

International Team The nature and physics of vortex flows in solar plasmas (funded by the International Space Science Institute (ISSI) Bern, Switzerland, since 2018).

Stellar physics

ChETEC-INFRA (Chemical Elements as Tracers of the Evolution of the Cosmos - Infrastructures for Nuclear Astrophysics), JRA3-WP5 „Astronuclear Abundances 2040“, associate partner.

Extrasolar planets and their host stars

Member of KOINet - Observations of extrasolar planets (Kepler Objects of Interest), amongst others with the Nordic Optical Telescope (since 2014)
Extreme Precision Radial Velocity group (EPRV, NASA/NSF, since 2019)
NASA’s EXOPAG SAG 21 on “The Effect of Stellar Contamination on Space-based Transmission Spectroscopy” (since 2020)
ARIEL (Atmospheric Remote-sensing Infrared Exoplanet Large-survey, ESA exoplanet detection mission), Consortium Supporting Member (since 2021)

Previous research

After finishing my PhD studies at the University of Kiel, Germany, which includes a stay at the University of Glasgow, UK, I was a post-doctoral research fellow at the Kiepenheuer Institute in Freiburg i.Br., Germany (2003-06). After receiving a Marie Curie Intra-European Fellowship, I started working at the Institute of Theoretical Astrophysics at the University of Oslo. During the recent years, I have been the PI of the MDWARF project and the VORTEX project, both funded by the Research Council of Norway.

Recent research highlights include the discovery and explanation of so-called magnetic tornadoes on the Sun, featured on the front page of Nature in 2012, and the ongoing development of methods for observing the Sun with the Atacama Large Millimeter/submillimeter Array, an application with potentially high impact for our understanding of the outer layers of our Sun and other stars.

Previous major research activities (in part ongoing)

The ERC-funded SolarALMA project ran from 2016 to 2021 and aimed at utilizing ALMA for detailed studies of the solar chromosphere with particular focus on the coronal heating problem.
"Vortex flows and magnetic tornadoes on the Sun and cool stars"
Funded by the Research Council of Norway in the highly competitive FRIPRO/FRINATEK program for the period 2013-2017.
Click here for the official ITA project page.
"Magnetic Activity of the Atmospheres of M-type Dwarf Stars"
Funded by the Research Council of Norway in the Space Science for the period 2012-2014. Further work based on the project results still ongoing.
Click here for the official ITA project page.
"Magnetic Activity of M-type Dwarf Stars and the Influence on Habitable Extra-solar Planets"
International Team funded by the International Space Science Institute (ISSI) in Bern, Switzerland (since 2012).
Click here for the official team home page at ISSI, Bern.

Emneord: Astronomi og astrofysikk, Solfysikk, Atacama Large Millimeter/submillimeter Array (ALMA), Solens kromosfære, Simulering, Stjerner, Extrasolar Planets, Nordisk Optisk Teleskop

de Oliveira e Silva, Alexandre José; Selhorst, Caius Lucius; Costa, Joaquim E. R.; Simões, Paulo J. A.; Giménez de Castro, Carlos Guillermo & Wedemeyer, Sven [Vis alle 9 forfattere av denne artikkelen] (2022). A Genetic Algorithm to Model Solar Radio Active Regions From 3D Magnetic Field Extrapolations. Frontiers in Astronomy and Space Sciences. 9. doi: 10.3389/fspas.2022.911118.
Mohan, Atul; Wedemeyer, Sven; Hauschildt, Peter, H.; Pandit, Sneha & Saberi, Maryam (2022). EMISSA (Exploring Millimeter Indicators of Solar-Stellar Activity) II. Towards a robust indicator of stellar activity. Astronomy and Astrophysics (A & A). ISSN 0004-6361. 664. doi: 10.1051/0004-6361/202244385. Fulltekst i vitenarkiv Vis sammendrag
Context: An activity indicator, which can provide a robust quantitative mapping between the stellar activity and the physical properties of its atmosphere, is important in exploring the evolution of the observed active phenomena across main-sequence stars of different spectral types. Common activity indicators do provide qualitative correlations with physical properties such as Teff and the rotation period, among others. However, due to the large variability in their values, even for a single star, defining robust quantitative mappings between activity and physical properties is difficult. Millimetre (mm) wavelengths probe the different atmospheric layers within the stellar chromosphere, providing a tomographic view of the atmospheric dynamics. Aims: The project aims to define a robust activity indicator by characterising mm brightness temperature spectra (TB(ν)) of the cool main-sequence stars (Teff ∼ 5000 – 7000 K) compiled by paper I in this series. The sample contains 13 stars, including the Sun. Methods: We derived the mm TB(ν) spectral indices (αmm) for cool stars, including the Sun, based on observations in the 30 – 1000 GHz range. The derived values for αmm are explored as a function of various physical parameters and empirical power-law functions were derived. We also compared αmm estimates with other activity indicators. Results: Despite the estimation errors, αmm values could distinguish the cool stars well, unlike common activity indicators. The low estimation errors on the derived trends of αmm versus physical parameters suggest that αmm could be a robust activity indicator. Conclusions: We note that αmm, which is linked to chromospheric thermal stratification and activity in cool stars, can well distinguish and physically characterise the stars more robustly than common activity indicators. We emphasise the need for multi-frequency data across the mm band for stars, with a range of physical parameters and gathered at multiple epochs during their activity cycles. This will help to explore αmm in a statistically robust manner and to study the emergence of chromospheric heating on the main sequence
Saberi, Maryam; Khouri, T.; Velilla-Prieto, L.; Fonfría, J.P.; Vlemmings, W.H.T. & Wedemeyer, Sven (2022). First detection of AlF line emission towards M-type AGB stars. Astronomy and Astrophysics (A & A). ISSN 0004-6361. 663. doi: 10.1051/0004-6361/202141704. Fulltekst i vitenarkiv
de Jorge Henriques, Vasco Manuel; Jafarzadeh, Shahin; Guevara Gomez, Juan Camilo; Eklund, Henrik; Wedemeyer, Sven & Szydlarski, Mikolaj [Vis alle 8 forfattere av denne artikkelen] (2022). The Solar ALMA Science Archive (SALSA): First release, SALAT, and FITS header standard. Astronomy and Astrophysics (A & A). ISSN 0004-6361. 659. doi: 10.1051/0004-6361/202142291. Fulltekst i vitenarkiv
Eklund, Henrik; Wedemeyer, Sven; Szydlarski, Mikolaj & Jafarzadeh, Shahin (2021). The Sun at millimeter wavelengths: III. Impact of the spatial resolution on solar ALMA observations. Astronomy and Astrophysics (A & A). ISSN 0004-6361. 656. doi: 10.1051/0004-6361/202140972. Fulltekst i vitenarkiv
Mohan, Atul; Wedemeyer, Sven; Pandit, Sneha; Saberi, Maryam & Hauschildt, Peter H. (2021). EMISSA (Exploring Millimeter Indicators of Solar-Stellar Activity): I. The initial millimeter–centimeter main-sequence star sample. Astronomy and Astrophysics (A & A). ISSN 0004-6361. 655. doi: 10.1051/0004-6361/202142095. Fulltekst i vitenarkiv
Chintzoglou, Georgios; De Pontieu, Bart Walter; Martinez-Sykora, Juan; Hansteen, Viggo; de la Cruz Rodriguez, Jaime & Szydlarski, Mikolaj Marcin [Vis alle 10 forfattere av denne artikkelen] (2021). ALMA and IRIS Observations of the Solar Chromosphere. II. Structure and Dynamics of Chromospheric Plages. The Astrophysical Journal (ApJ). ISSN 0004-637X. 906(2). doi: 10.3847/1538-4357/abc9b0.
Chintzoglou, Georgios; De Pontieu, Bart Walter; Martinez-Sykora, Juan; Hansteen, Viggo; de la Cruz Rodriguez, Jaime & Szydlarski, Mikolaj Marcin [Vis alle 10 forfattere av denne artikkelen] (2021). ALMA and IRIS Observations of the Solar Chromosphere. I. An On-Disk Type II Spicule. The Astrophysical Journal (ApJ). ISSN 0004-637X. 906(2). doi: 10.3847/1538-4357/abc9b1.
Guevara Gomez, Juan Camilo; Jafarzadeh, Shahin; Wedemeyer, Sven; Szydlarski, Mikolaj Marcin; Stangalini, M. & Fleck, Bernhard [Vis alle 7 forfattere av denne artikkelen] (2020). High-frequency oscillations in small chromospheric bright features observed with Atacama Large Millimetre/Submillimetre Array. Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences. ISSN 1364-503X. 379(2190). doi: 10.1098/rsta.2020.0184. Fulltekst i vitenarkiv
Eklund, Henrik; Wedemeyer, Sven; Snow, Ben; Jess, David B.; Jafarzadeh, Shahin & Grant, Samuel D. T. [Vis alle 8 forfattere av denne artikkelen] (2020). Characterization of shock wave signatures at millimetre wavelengths from Bifrost simulations. Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences. ISSN 1364-503X. 379(2190). doi: 10.1098/rsta.2020.0185. Fulltekst i vitenarkiv
Jafarzadeh, Shahin; Wedemeyer, Sven; Fleck, Bernhard; Stangalini, M.; Jess, D. B. & Morton, R. J. [Vis alle 15 forfattere av denne artikkelen] (2020). An overall view of temperature oscillations in the solar chromosphere with ALMA. Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences. ISSN 1364-503X. 379(2190). doi: 10.1098/rsta.2020.0174. Fulltekst i vitenarkiv
Eklund, Henrik; Wedemeyer, Sven; Szydlarski, Mikolaj Marcin; Jafarzadeh, Shahin & Guevara Gomez, Juan Camilo (2020). The Sun at millimeter wavelengths: II. Small-scale dynamic events in ALMA Band 3. Astronomy and Astrophysics (A & A). ISSN 0004-6361. 644. doi: 10.1051/0004-6361/202038250. Fulltekst i vitenarkiv
Wedemeyer, Sven; Szydlarski, Mikolaj Marcin; de la Cruz Rodriguez, Jaime & Jafarzadeh, Shahin (2020). Observing the Sun with the Atacama Large Millimeter/submillimeter Array-from continuum to magnetic fields. Proceedings of the International Astronomical Union. ISSN 1743-9213. 15(S354), s. 24–37. doi: 10.1017/S1743921319009906.
da Silva Santos, João Manuel; de la Cruz Rodriguez, Jaime; Leenaarts, Jorrit; Chintzoglou, Georgios; De Pontieu, Bart Walter & Wedemeyer, Sven [Vis alle 7 forfattere av denne artikkelen] (2020). The multi-thermal chromosphere: Inversions of ALMA and IRIS data. Astronomy and Astrophysics (A & A). ISSN 0004-6361. 634. doi: 10.1051/0004-6361/201937117. Fulltekst i vitenarkiv
Wedemeyer, Sven; Szydlarski, Mikolaj Marcin; Jafarzadeh, Shahin; Eklund, Henrik; Guevara Gomez, Juan Camilo & Bastian, Tim [Vis alle 10 forfattere av denne artikkelen] (2020). The Sun at millimeter wavelengths: I. Introduction to ALMA Band 3 observations. Astronomy and Astrophysics (A & A). ISSN 0004-6361. 635. doi: 10.1051/0004-6361/201937122. Fulltekst i vitenarkiv
von Essen, Carolina; Wedemeyer, Sven; Sosa, M. S.; Hjorth, M.; Parkash, V. & Freudenthal, J. [Vis alle 11 forfattere av denne artikkelen] (2019). Indications for transit-timing variations in the exo-Neptune HAT-P-26b. Astronomy and Astrophysics (A & A). ISSN 0004-6361. 628. doi: 10.1051/0004-6361/201731966. Fulltekst i vitenarkiv
Freudenthal, J.; von Essen, Carolina; Ofir, A.; Dreizler, S.; Agol, E. & Wedemeyer, Sven [Vis alle 16 forfattere av denne artikkelen] (2019). Kepler Object of Interest Network: III. Kepler-82f: a new non-transiting 21 M⊕ planet from photodynamical modelling. Astronomy and Astrophysics (A & A). ISSN 0004-6361. 628. doi: 10.1051/0004-6361/201935879. Fulltekst i vitenarkiv
Shetye, Juie; Verwichte, Erwin; Stangalini, Marco; Judge, Philip G.; Doyle, J. G. & Arber, Tony [Vis alle 8 forfattere av denne artikkelen] (2019). Multiwavelength High-resolution Observations of Chromospheric Swirls in the Quiet Sun. The Astrophysical Journal (ApJ). ISSN 0004-637X. 881(1). doi: 10.3847/1538-4357/ab2bf9. Fulltekst i vitenarkiv
Jafarzadeh, Shahin; Wedemeyer, Sven; Szydlarski, Mikolaj Marcin; De Pontieu, Bart Walter; Rezaei, Rezza & Carlsson, Mats (2019). The solar chromosphere at millimetre and ultraviolet wavelengths: I. Radiation temperatures and a detailed comparison. Astronomy and Astrophysics (A & A). ISSN 0004-6361. 622. doi: 10.1051/0004-6361/201834205. Fulltekst i vitenarkiv
Rodger, Andrew S.; Labrosse, Nicolas; Wedemeyer, Sven; Szydlarski, Mikolaj Marcin; Simões, Paulo J. A. & Fletcher, Lyndsay (2019). First Spectral Analysis of a Solar Plasma Eruption Using ALMA. The Astrophysical Journal (ApJ). ISSN 0004-637X. 875(2). doi: 10.3847/1538-4357/aafdfb. Fulltekst i vitenarkiv
Nindos, A.; Alissandrakis, C. E.; Bastian, T. S.; Patsourakos, S.; De Pontieu, Bart Walter & Warren, H. [Vis alle 12 forfattere av denne artikkelen] (2018). First high-resolution look at the quiet Sun with ALMA at 3mm. Astronomy and Astrophysics (A & A). ISSN 0004-6361. 619. doi: 10.1051/0004-6361/201834113. Fulltekst i vitenarkiv
Freudenthal, Jantje; von Essen, Carolina; Dreizler, Stefan; Wedemeyer, Sven; Agol, Eric & Morris, Brett M. [Vis alle 17 forfattere av denne artikkelen] (2018). Kepler Object of Interest Network: II. Photodynamical modelling of Kepler-9 over 8 years of transit observations. Astronomy and Astrophysics (A & A). ISSN 0004-6361. 618. doi: 10.1051/0004-6361/201833436. Fulltekst i vitenarkiv
von Essen, Carolina; Ofir, A.; Dreizler, S.; Agol, E.; Freudenthal, J. & Hernández, J. [Vis alle 38 forfattere av denne artikkelen] (2018). Kepler Object of Interest Network: I. First results combining ground- and space-based observations of Kepler systems with transit timing variations. Astronomy and Astrophysics (A & A). ISSN 0004-6361. 615. doi: 10.1051/0004-6361/201732483. Fulltekst i vitenarkiv
Bastian, Timothy; Barta, Miroslav; Brajša, Roman; Chen, Bin; De Pontieu, Bart Walter & Gary, D. E. [Vis alle 18 forfattere av denne artikkelen] (2018). Exploring the Sun with ALMA. The Messenger. ISSN 0722-6691. 171, s. 25–30. Fulltekst i vitenarkiv
Brajša, R.; Sudar, D.; Benz, A. O.; Skokić, I.; Bárta, M. & De Pontieu, Bart Walter [Vis alle 14 forfattere av denne artikkelen] (2018). First analysis of solar structures in 1.21 mm full-disc ALMA image of the Sun. Astronomy and Astrophysics (A & A). ISSN 0004-6361. 613. doi: 10.1051/0004-6361/201730656. Fulltekst i vitenarkiv
Klevas, J.; Kučinskas, A.; Wedemeyer, Sven & Ludwig, H.-G. (2018). Impact of magnetic fields on the structure of convective atmospheres of red giant stars. Contributions of the Astronomical Observatory Skalnate Pleso. ISSN 1335-1842. 48(1), s. 280–281. Fulltekst i vitenarkiv
Klevas, Jonas; Wedemeyer, Sven; Kucinskas, Arunas & Ludwig, Hans-Günter (2017). 3D hydrodynamical COBOLD simulations of a chromosphere of a red giant. MEMORIE della Società Astronomica Italiana. ISSN 0037-8720. 88(1), s. 100–103. doi: 10.1051/0004-6361/201730405.
Wedemeyer, Sven; Kučinskas, Arūnas; Klevas, Jonas & Ludwig, Hans-Günter (2017). Three-dimensional hydrodynamical CO5BOLD model atmospheres of red giant stars: VI. First chromosphere model of a late-type giant. Astronomy and Astrophysics (A & A). ISSN 0004-6361. 606. doi: 10.1051/0004-6361/201730405. Fulltekst i vitenarkiv
Shimojo, M.; Bastian, T. S.; Hales, A. S.; White, S. M.; Iwai, K. & Hills, R. E. [Vis alle 28 forfattere av denne artikkelen] (2017). Observing the Sun with the Atacama Large Millimeter/submillimeter Array (ALMA): High-Resolution Interferometric Imaging. Solar Physics. ISSN 0038-0938. 292(7). doi: 10.1007/s11207-017-1095-2. Fulltekst i vitenarkiv
White, S. M.; Iwai, K.; Phillips, N. M.; Hills, R. E.; Hirota, A. & Yagoubov, P. [Vis alle 34 forfattere av denne artikkelen] (2017). Observing the Sun with the Atacama Large Millimeter/submillimeter Array (ALMA): Fast-Scan Single-Dish Mapping. Solar Physics. ISSN 0038-0938. 292(7). doi: 10.1007/s11207-017-1123-2. Fulltekst i vitenarkiv
Kato, Yoshiaki & Wedemeyer, Sven (2017). Vortex flows in the solar chromosphere: I. Automatic detection method. Astronomy and Astrophysics (A & A). ISSN 0004-6361. 601. doi: 10.1051/0004-6361/201630082. Fulltekst i vitenarkiv
Wedemeyer, Sven & Ludwig, Hans-Günter (2016). Synthetic activity indicators for M-type dwarf stars. Proceedings of the International Astronomical Union. ISSN 1743-9213. 11(S320), s. 303–308. doi: 10.1017/S1743921316000077.
Scullion, Eamon; Rouppe, Van Der Voort Luc; Antolin, Patrick; Wedemeyer, Sven; Vissers, Gregal Joan Maria & Kontar, E. P. [Vis alle 7 forfattere av denne artikkelen] (2016). Observing the Formation of Flare-Driven Coronal Rain. The Astrophysical Journal (ApJ). ISSN 0004-637X. 833(2). doi: 10.3847/1538-4357/833/2/184.
Kato, Yoshiaki; Steiner, Oskar; Hansteen, Viggo; Gudiksen, Boris Vilhelm; Wedemeyer, Sven & Carlsson, Mats (2016). Chromospheric and Coronal Wave Generation in a Magnetic Flux Sheath. The Astrophysical Journal (ApJ). ISSN 0004-637X. 827(1). doi: 10.3847/0004-637X/827/1/7.
Wedemeyer, Sven; Bastian, T.; Brajsa, R.; Hudson, H.; Fleishman, G. & Loukitcheva, M. [Vis alle 38 forfattere av denne artikkelen] (2016). Solar Science with the Atacama Large Millimeter/Submillimeter Array—A New View of Our Sun. Space Science Reviews. ISSN 0038-6308. 200(1), s. 1–73. doi: 10.1007/s11214-015-0229-9.
Phillips, Neil; Hills, Richard; Bastian, Timothy; Hudson, Hugh; Marson, Ralph & Wedemeyer, Sven (2015). Fast single-dish scans of the Sun using ALMA. Astronomical Society of the Pacific Conference Series. ISSN 1050-3390. 499, s. 347–348.
Wedemeyer, Sven & Parmer, Asbjørn Lie (2015). ALMA's high-cadence imaging capabilities for solar observations. Astronomical Society of the Pacific Conference Series. ISSN 1050-3390. 499, s. 343–344.
Wedemeyer, Sven; Bastian, Timothy; Brajša, Roman; Barta, Miroslav & Shimojo, Masumi (2015). Solar Simulations for the Atacama Large Millimeter Observatory Network. Astronomical Society of the Pacific Conference Series. ISSN 1050-3390. 499, s. 341–342.
Wedemeyer, Sven; Bastian, Timothy; Brajša, Roman; Barta, Miroslav; Shimojo, Masumi & Hales, Antonio [Vis alle 8 forfattere av denne artikkelen] (2015). Solar ALMA Observations - A new view of our host star. Astronomical Society of the Pacific Conference Series. ISSN 1050-3390. 499, s. 345–346.
Wedemeyer, Sven; Bastian, Timothy; Brajša, Roman; Barta, Miroslav; Hudson, Hugh & Fleishman, Gregory [Vis alle 29 forfattere av denne artikkelen] (2015). SSALMON - The Solar Simulations for the Atacama Large Millimeter Observatory Network. Advances in Space Research. ISSN 0273-1177. 56(12), s. 2679–2692. doi: 10.1016/j.asr.2015.05.027.
Tremblay, P. E.; Fontaine, G.; Freytag, B.; Steiner, O.; Ludwig, Hans-Günter & Steffen, M. [Vis alle 8 forfattere av denne artikkelen] (2015). ON the EVOLUTION of MAGNETIC WHITE DWARFS. The Astrophysical Journal (ApJ). ISSN 0004-637X. 812(1). doi: 10.1088/0004-637X/812/1/19.
Wedemeyer-Böhm, Sven & Steiner, Oskar (2014). On the plasma flow inside magnetic tornadoes on the Sun. Publications of the Astronomical Society of Japan (PASJ). ISSN 0004-6264. 66(1). doi: 10.1093/pasj/psu086.
Scullion, Eamon; Rouppe, Van Der Voort Luc; Wedemeyer-Böhm, Sven & Antolin, Patrick (2014). Unresolved Fine-Scale Structure in Solar Coronal Loop-Tops. The Astrophysical Journal (ApJ). ISSN 0004-637X. 797(1). doi: 10.1088/0004-637X/797/1/36. Fulltekst i vitenarkiv
Freij, N.; Scullion, Eamon; Nelson, C. J.; Mumford, S.; Wedemeyer-Böhm, Sven & Erdélyi, R. (2014). The detection of upwardly propagating waves channeling energy from the chromosphere to the low corona. The Astrophysical Journal (ApJ). ISSN 0004-637X. 791(1). doi: 10.1088/0004-637X/791/1/61. Fulltekst i vitenarkiv
Wedemeyer-Böhm, Sven (2013). The CO5BOLD analysis tool. Memorie della Societa Astronomica Italiana Supplement. ISSN 1824-0178. 24, s. 96–99.
Ayres, T. R.; Lyons, J. R.; Ludwig, Hans-Günter; Caffau, E. & Wedemeyer-Böhm, Sven (2013). Solar carbon monoxide: poster child for 3D effects. Memorie della Societa Astronomica Italiana Supplement. ISSN 1824-0178. 24, s. 85–95.
Wedemeyer-Böhm, Sven; Ludwig, Hans-Günter & Steiner, Oskar (2013). Three-dimensional magnetohydrodynamic simulations of M-dwarf chromospheres. Astronomical Notes - Astronomische Nachrichten. ISSN 0004-6337. 334(1-2), s. 137–140. doi: 10.1002/asna.201211741.
Wedemeyer-Böhm, Sven; Scullion, Eamon; Steiner, Oskar; de la Cruz Rodriguez, Jaime & Rouppe, Van Der Voort Luc (2013). Magnetic tornadoes and chromospheric swirls - Definition and classification. Journal of Physics: Conference Series (JPCS). ISSN 1742-6588. 440(1). doi: 10.1088/1742-6596/440/1/012005.
Wedemeyer-Böhm, Sven; Scullion, Eamon; Rouppe, Van Der Voort Luc; Bosnjak, Antonija & Antolin, Patrick (2013). Are Giant Tornadoes the Legs of Solar Prominences? The Astrophysical Journal (ApJ). ISSN 0004-637X. 774(2). doi: 10.1088/0004-637X/774/2/123.
Ayres, T. R.; Lyons, J. R.; Ludwig, Hans-Günter; Caffau, E. & Wedemeyer-Böhm, Sven (2013). IS THE SUN LIGHTER THAN THE EARTH? ISOTOPIC CO IN THE PHOTOSPHERE, VIEWED THROUGH THE LENS OF THREE-DIMENSIONAL SPECTRUM SYNTHESIS. The Astrophysical Journal (ApJ). ISSN 0004-637X. 765(1). doi: 10.1088/0004-637X/765/1/46.
Wedemeyer-Böhm, Sven; Scullion, Eamon; Steiner, O.; Rouppe, Van Der Voort Luc; de la Cruz Rodriguez, Jaime & Fedun, V. [Vis alle 7 forfattere av denne artikkelen] (2012). Magnetic tornadoes as energy channels into the solar corona. Nature. ISSN 0028-0836. 486(7404), s. 505–508. doi: 10.1038/nature11202.
Freytag, Bernd; Steffen, Matthias; Ludwig, Hans-Günter; Wedemeyer-Böhm, Sven; Schaffenberger, Werner & Steiner, Oskar (2012). Simulations of stellar convection with CO5BOLD. Journal of Computational Physics. ISSN 0021-9991. 231(3), s. 919–959. doi: 10.1016/j.jcp.2011.09.026.
Wedemeyer-Böhm, Sven & Carlsson, Mats (2011). Non-equilibrium calcium ionisation in the solar atmosphere. Astronomy and Astrophysics (A & A). ISSN 0004-6361. 528. doi: 10.1051/0004-6361/201016186.
Wöger, Friedrich; Wedemeyer-Böhm, Sven; Uitenbroek, H. & Rimmele, T. R. (2010). Recovering the line-of-sight magnetic field in the chromosphere from Ca II IR spectra. MEMORIE della Società Astronomica Italiana. ISSN 0037-8720. 81, s. 598–603.
Haberreiter, Margit; Finsterle, W; McIntosh, S.W. & Wedemeyer-Böhm, Sven (2010). Toward the analysis of waves in the solar atmosphere based on NLTE spectral synthesis from 3D MHD simulations. MEMORIE della Società Astronomica Italiana. ISSN 0037-8720. 81, s. 782–785.
Wedemeyer-Böhm, Sven (2010). Small-scale structure and dynamics of the chromospheric magnetic field. MEMORIE della Società Astronomica Italiana. ISSN 0037-8720. 81, s. 693–700.
Kjeldseth-Moe, Olav & Wedemeyer-Böhm, Sven (2010). Are there variations in Earth's global mean temperature related to the solar activity? Proceedings of the International Astronomical Union. ISSN 1743-9213. 5, s. 320–325. doi: 10.1017/S1743921309992869.
Wedemeyer-Böhm, Sven; Lagg, Andreas & Nordlund, Åke (2009). Coupling from the Photosphere to the Chromosphere and the Corona. Space Science Reviews. ISSN 0038-6308. 144(1-4), s. 317–350. doi: 10.1007/s11214-008-9447-8.
Wedemeyer-Böhm, Sven & Rouppe, Van Der Voort Luc (2009). On the continuum intensity distribution of the solar photosphere. Astronomy and Astrophysics (A & A). ISSN 0004-6361. 503(1), s. 225–239. doi: 10.1051/0004-6361/200911983.
Wedemeyer-Böhm, Sven & Rouppe, Van Der Voort Luc (2009). The solar continuum intensity distribution. Settling the conflict between observations and simulations. MEMORIE della Società Astronomica Italiana. ISSN 0037-8720. 80.
Wedemeyer-Böhm, Sven & Rouppe, Van Der Voort Luc (2009). Small-scale swirl events in the quiet Sun chromosphere. Astronomy and Astrophysics (A & A). ISSN 0004-6361. 507(1), s. L9–L12. doi: 10.1051/0004-6361/200913380.
Wöger, Friedrich; Wedemeyer-Böhm, Sven; Uitenbroek, H. & Rimmele, T. R. (2009). MORPHOLOGY AND DYNAMICS OF THE LOW SOLAR CHROMOSPHERE. The Astrophysical Journal (ApJ). ISSN 0004-637X. 706(1), s. 148–157. doi: 10.1088/0004-637X/706/1/148.
Wedemeyer-Böhm, Sven & Wöger, Friedrich (2008). Small-scale structure and dynamics of the lower solar atmosphere. I Erdélyi, R. & Mendoza-Briceno, C. A. (Red.), Waves and Oscillations in the Solar Atmosphere: Heating and Magneto-Seismology. Cambridge University Press. ISSN 0-521-874696. s. 66–73.
Wedemeyer-Böhm, Sven (2008). Point spread functions for the Solar optical telescope onboard Hinode. Astronomy and Astrophysics (A & A). ISSN 0004-6361. 487, s. 399–412. doi: 10.1051/0004-6361%3A200809819.
Wedemeyer-Böhm, Sven; Lagg, Andreas & Nordlund, Åke (2008). Coupling from the photosphere to the chromosphere and the corona. Space Science Reviews. ISSN 0038-6308. OnlineFirst. doi: 10.1007/s11214-008-9447-8.
Steiner, Oskar; Rezaei, Rezza; Schaffenberger, Werner & Wedemeyer-Böhm, Sven (2008). The Horizontal Internetwork Magnetic Field: Numerical Simulations in Comparison to Observations with Hinode. The Astrophysical Journal (ApJ). ISSN 0004-637X. 680(1), s. L85–L88.
Wedemeyer-Böhm, Sven; Steiner, O.; Bruls, J. & Rammacher, W. (2007). What is Heating the Quiet-Sun Chromosphere? I Heinzel, Petr; Dorotovic, Ivan & Rutten, Robert (Red.), The Physics of Chromospheric Plasmas. Astronomical Society of the Pacific. ISSN 978-1-583812-36-5. s. 93–102.
Leenaarts, Jorrit; Wedemeyer-Böhm, Sven; Carlsson, Mats Per-Olof & Hansteen, Viggo (2007). Non-equilibrium Hydrogen Ionization in the Solar Atmosphere. I Heinzel, Petr; Dorotovic, Ivan & Rutten, Robert (Red.), The Physics of Chromospheric Plasmas. Astronomical Society of the Pacific. ISSN 978-1-583812-36-5. s. 103–106.
Wedemeyer-Böhm, Sven & Steffen, M. (2007). Carbon monoxide in the solar atmosphere II. Radiative cooling by CO lines. Astronomy and Astrophysics (A & A). ISSN 0004-6361. 462, s. L31–L35. doi: 10.1051/0004-6361%3A20066173.
Steiner, O.; Vigeesh, G.; Krieger, L.; Wedemeyer-Böhm, Sven; Schaffenberger, W. & Freytag, B. (2007). First local helioseismic experiments with CO(5)BOLD. Astronomical Notes - Astronomische Nachrichten. ISSN 0004-6337. 328. doi: 10.1002/asna.200610738.
Wedemeyer-Böhm, Sven; Ludwig, HG; Steffen, M.; Leenaarts, J. & Freytag, B. (2007). Inter-network regions of the Sun at millimetre wavelengths. Astronomy and Astrophysics (A & A). ISSN 0004-6361. 471, s. 977–991. doi: 10.1051/0004-6361%3A20077588.
Rezaei, R.; Steiner, O.; Wedemeyer-Böhm, Sven; Schlichenmaier, R.; Schmidt, W. & Lites, B.W. (2007). Hinode observations reveal boundary layers of magnetic elements in the solar photosphere. Astronomy and Astrophysics (A & A). ISSN 0004-6361. 476, s. L33–L36. doi: 10.1051/0004-6361%3A20078371.
Leenaarts, Jorrit & Wedemeyer-Boehm, S. (2006). Time-dependent hydrogen ionisation in 3D simulations of the solar chromosphere - Methods and first results. Astronomy and Astrophysics (A & A). ISSN 0004-6361. 460, s. 301–307.

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Pandit, Sneha & Wedemeyer, Sven (2022). The Formation of Activity Indicators in 3D Model Atmosphere.
Pandit, Sneha & Wedemeyer, Sven (2022). Formation of Activity Indicators in a 3D model Atmosphere.
Pandit, Sneha; Wedemeyer, Sven & Carlsson, Mats (2022). Formation of Activity Indicators in a 3D Model Atmosphere.
Saberi, Maryam; Khouri, T.; Velilla-Prieto, L.; Fonfria, J. P.; Vlemmings, W. & Wedemeyer, Sven (2022). Tracing the role of AGB stars in the Galactic Fluorine budget .
Guevara Gomez, Juan Camilo; Jafarzadeh, Shahin & Wedemeyer, Sven (2021). Oscillations in chromospheric small-scale bright features observed with ALMA.
Saberi, Maryam; Khouri, Theo; Velilla-Prieto, L.; Fonfria, . P.; Vlemmings, W. & Wedemeyer, Sven (2021). Tracing the role of AGB stars in the Galactic Fluorine budget .
Wedemeyer, Sven; Szydlarski, Mikolaj; Jafarzadeh, Shahin; Henriques, Vasco; Guevara Gomez, Juan Camilo & Eklund, Henrik [Vis alle 10 forfattere av denne artikkelen] (2021). Lessons learned from 5 years of solar observing with ALMA.
Wedemeyer, Sven; Szydlarski, Mikolaj; Jafarzadeh, Shahin; Henriques, Vasco; Eklund, Henrik & Guevara Gomez, Juan Camilo [Vis alle 11 forfattere av denne artikkelen] (2021). A brief introduction to solar observing with ALMA .
Wedemeyer, Sven; Szydlarski, Mikolaj; Jafarzadeh, Shahin; Henriques, Vasco; Eklund, Henrik & Guevara Gomez, Juan Camilo [Vis alle 10 forfattere av denne artikkelen] (2021). Five years observing the solar chromosphere with ALMA - First results and future opportunities.
Guevara Gomez, Juan Camilo; Jafarzadeh, Shahin & Wedemeyer, Sven (2021). Oscillations in small-scale bright features observed with ALMA. Vis sammendrag
Small-scale chromospheric bright features in a plage/enhanced network are identified in solar ALMA observations. The features present oscillations in brightness temperature, size and horizontal velocity. Interestingly, an anti-correlation between brightness temperature and size is also evident, suggesting that these features might be associated to fast-sausage MHD modes. A statistical analysis is carried out to quantify the oscillation periods of the three quantities and the phase angles between the perturbations in temperature and size. The values found are in agreement with periods of high frequency oscillations in other layers of the solar atmosphere.
Guevara Gomez, Juan Camilo & Wedemeyer, Sven (2021). Dynamics of small-scale dark features observed by the Atacama Large Millimeter/Submillimeter Array (ALMA). Vis sammendrag
Observations of the Sun with the Atacama Large Millimeter/submillimeter Array (ALMA) now allow for more quantitative determination of temperatures in the chromosphere. ALMA observations of Quiet Sun regions in receiver Band 3 (3 mm; 100 GHz) exhibit small-scale features that resemble a mesh-like chromospheric pattern, similar to what was earlier detected with other chromospheric diagnostics. Tracking the features in time results in lifetimes, velocities and sizes, which are analysed within the context given by co-aligned images of the Solar Dynamics Observatory (SDO). Here we present a statistical analysis and compare the results with a 3D MHD simulation with Bifrost of an enhanced network which has been degraded to the ALMA spatial resolution. The match between observations and simulations suggests that the dark features are post-shock regions. The thermodynamics and kinetic properties derived from the ALMA observations will therefore enhance our understanding of the small-scale dynamics and heating of the solar chromosphere and its potential implications for other solar-like stars.
Saberi, Maryam; Jafarzadeh, Shahin; Gafeira, Ricardo; Wedemeyer, Sven & Szydlarski, Mikolaj (2021). MHD waves in chromospheric fibrillar structures as observed with ALMA.
Wedemeyer, Sven (2021). Sola over Atacama-ørkenen. Astronomi. ISSN 0802-7587. 2, s. 36–39.
Jafarzadeh, Shahin; Gafeira, Ricardo; Wedemeyer, Sven & Szydlarski, Mikolaj (2021). MHD waves in chromospheric fibrillar structures as observed with ALMA.
Pandit, Sneha & Wedemeyer, Sven (2021). The sun as a star: new insights from the full disk observations with ALMA.
Wedemeyer, Sven; Szydlarski, Mikolaj; Jafarzadeh, Shahin; de Jorge Henriques, Vasco Manuel; Eklund, Henrik & Guevara Gomez, Juan Camilo [Vis alle 10 forfattere av denne artikkelen] (2021). Observing the Sun with ALMA - First results and future opportunities.
Wedemeyer, Sven; Szydlarski, Mikolaj; Jafarzadeh, Shahin; de Jorge Henriques, Vasco Manuel; Eklund, Henrik & Guevara Gomez, Juan Camilo [Vis alle 10 forfattere av denne artikkelen] (2021). Five years observing the solar chromosphere with ALMA - First results and future opportunities.
Guevara Gomez, Juan Camilo & Wedemeyer, Sven (2021). Dynamics of small-scale dark features observed by the Atacama Large Millimeter/submillimeter Array (ALMA).
White, Stephen; Barta, Miroslav; Bastian, Timothy; Shimojo, Masumi & Wedemeyer, Sven (2020). Correlator Desiderata for Solar Radiophysics at ALMA.
Eklund, Henrik; Szydlarski, Mikolaj Marcin & Wedemeyer, Sven (2020). Image reconstruction of interferometric ALMA data.
Wedemeyer, Sven (2020). Development of tools for solar research with ALMA at RoCS.
Wedemeyer, Sven (2020). Observing the Sun with ALMA – Challenges, scientific potential, and first results.
Wedemeyer, Sven (2020). Magnetic Tornadoes on the Sun.
Wedemeyer, Sven (2019). Magnetic Field Measurements with the Atacama Millimeter/submillimeter Array.
Wedemeyer, Sven (2019). Solar science with ALMA in Norway.
Wedemeyer, Sven (2019). High-tech and llamas.
Wedemeyer, Sven (2019). High-cadence imaging of the Sun .
Wedemeyer, Sven (2019). Solar Astronomy with ALMA .
Jafarzadeh, Shahin; Wedemeyer, Sven; Noda, Carlos Quintero; Wiegelmann, Thomas & Rouppe van der Voort, Luc (2019). Magnetic-field topology throughout the solar chromosphere.
Jafarzadeh, Shahin; Wedemeyer, Sven; Szydlarski, Mikolaj Marcin; Fleck, Bernhard & Stangalini, Marco (2019). Wave heating of the solar chromosphere from observations with ALMA.
Jafarzadeh, Shahin; Wedemeyer, Sven; Szydlarski, Mikolaj Marcin & Fleck, Bernhard (2019). Wave heating of the lower solar atmosphere.
Jafarzadeh, Shahin; van der Voort, Luc H.M. Rouppe; Wedemeyer, Sven & Noda, Carlos Quintero (2019). Magnetic-field topology of fibrillar structures throughout the solar chromosphere.
Jafarzadeh, Shahin; Wedemeyer, Sven & Szydlarski, Mikolaj Marcin (2019). Temperature Fluctuations in the Solar Chromosphere with ALMA.
Jafarzadeh, Shahin & Wedemeyer, Sven (2019). Observing Waves in the Lower Solar Atmosphere with ALMA.
Eklund, Henrik; Szydlarski, Mikolaj Marcin & Wedemeyer, Sven (2019). Shock wave propagation with high cadence solar ALMA time series.
Guevara Gomez, Juan Camilo; Wedemeyer, Sven; Jafarzadeh, Shahin & Szydlarski, Mikolaj Marcin (2019). Dynamics of solar isolated features observed by the Atacama Large Millimeter/submillimeter Array (ALMA).
Guevara Gomez, Juan Camilo; Wedemeyer, Sven; Jafarzadeh, Shahin & Szydlarski, Mikolaj Marcin (2019). Structure and dynamics of isolated features in the solar chromosphere observed with ALMA.
Wedemeyer, Sven (2019). Our Dynamic Sun.
Eklund, Henrik; Szydlarski, Mikolaj Marcin & Wedemeyer, Sven (2018). Interferometric ALMA observations and data processing.
Wedemeyer, Sven (2018). Experiences from applying for an ERC Consolidator Grant.
Wedemeyer, Sven (2018). Oppvarming av solens atmosfære & solfysikkforskning i dag.
Wedemeyer, Sven (2018). Sola, din nærmeste stjerne .
Wedemeyer, Sven (2018). Solar Observations with ALMA.
Wedemeyer, Sven (2015). Rød sol og evig daggry: Leting etter liv på fjerne kloder. I Kristiansen, Jostein Riiser; Evans, Anna Kathinka Dalland; Svensen, Henrik; Samset, Bjørn Hallvard & Byhring, Hanne Sigrun (Red.), Stjerneklart – siste nytt fra verdensrommet. Spartacus. ISSN 9788243009738. s. 96–108.
Ayres, T. R.; Lyons, J. R.; Ludwig, Hans-Günter; Caffau, E. & Wedemeyer-Böhm, Sven (2013). Isotopic CO in the Solar Photosphere, Viewed Through the Lens of 3D Spectrum Synthesis.
Wedemeyer-Böhm, Sven & van der Voort, Luc Rouppe (2010). The solar continuum intensity distribution. Proceedings of the International Astronomical Union. ISSN 1743-9213. 15, s. 333–334.
Kjeldseth-Moe, Olav & Wedemeyer-Böhm, Sven (2009). Are there variations in Earth’s global mean temperature related to the solar activity?
Rezaei, Rezza; Steiner, Oskar; Wedemeyer-Böhm, Sven; Schlichenmaier, Rolf & Lites, Bruce W. (2007). Variation of the Stokes-V area asymmetry across magnetic elements. Astronomical Notes - Astronomische Nachrichten. ISSN 0004-6337. 328(7).
Wedemeyer-Böhm, Sven (2007). Small-scale structure and dynamics of the lower solar atmosphere.
Guevara Gomez, Juan Camilo; Wedemeyer, Sven & Rouppe van der Voort, Luc (2022). Observations of the dynamics and structure of the solar atmosphere with ALMA . Universitetet i Oslo. ISSN 1501-7710.
Eklund, Henrik & Wedemeyer, Sven (2021). Investigating dynamic small-scale events in the Sun with the Atacama Large Millimeter/sub-millimeter Array. Faculty of Mathematics and Natural Sciences. ISSN 1501-7710.
Gaudi, Scott; Blackwood, Gary; Howard, Andrew; Latham, David; Fischer, Debra & Wedemeyer, Sven (2019). Extreme Precision Radial Velocity (EPRV) Working Group. Bulletin of the American Astronomical Society.

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Publisert 3. nov. 2010 15:21 - Sist endret 22. sep. 2022 15:20

Sven Wedemeyer

Primary research fields

Current main positions and functions

Current major research activities

Solar/Stellar Science with the Atacama Large Millimeter Array

Small-scale dynamics and energy balance of the solar atmosphere

Stellar physics

Extrasolar planets and their host stars

Previous research

Previous major research activities (in part ongoing)

Publikasjoner

Prosjekter

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