Browsing Institutt for teoretisk astrofysikk by Title

Now showing items 1245-1264 of 1279

  • Understanding the heating mechanism of the solar active region atmosphere in chromosphere 
    Yalim, Mehmet Sarp; Zank, Gary; Beck, Christian; Choudhary, Debi Prasad; Prasad, Avijeet; Hu, Qiang; Frisse, Makayla (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2023)
    Abstract Understanding the mechanisms underlying the heating of the solar atmosphere is a fundamental problem in solar physics. In this paper, we present an overview of our research on understanding the heating ...
  • A UNIFIED COMPUTATIONAL MODEL for SOLAR and STELLAR FLARES 
    Allred, Joel C.; Kowalski, Adam F.; Carlsson, Mats (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2015)
    We present a unified computational framework that can be used to describe impulsive flares on the Sun and on dMe stars. The models assume that the flare impulsive phase is caused by a beam of charged particles that is ...
  • Unified description of screened modified gravity 
    Brax, P; Davis, A.-C.; Li, Baojiu; Winther, Hans Arnold (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2012)
    We consider modified gravity models driven by a scalar field whose effects are screened in high density regions due to the presence of nonlinearities in its interaction potential and/or its coupling to matter. Our approach ...
  • Unifying static analysis of gravitational structures with a scale-dependent scalar field gravity as an alternative to dark matter 
    Salzano, Vincenzo; Mota, David; Capoziello, S.; Napolitano, N. R. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2014)
    Aims: We investigated the gravitational effects of a scalar field within scalar-tensor gravity as an alternative to dark matter. Motivated by chameleon, symmetron, and f(R)-gravity models, we studied a phenomenological ...
  • Universal predictions of screened modified gravity on cluster scales 
    Gronke, Max Balthasar; Mota, David; Winther, Hans Arnold (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2015)
    Modified gravity models require a screening mechanism to be able to evade the stringent constraints from local gravity experiments and, at the same time, give rise to observable astrophysical and cosmological signatures. ...
  • The Universe Is Reionizing at z ~ 7: Bayesian Inference of the IGM Neutral Fraction Using Lyα Emission from Galaxies 
    Mason, Charlotte A.; Treu, Tommaso; Dijkstra, Mark; Mesinger, Andrei; Trenti, Michele; Pentericci, Laura; De Barros, Stephane; Vanzella, Eros (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2018)
    We present a new flexible Bayesian framework for directly inferring the fraction of neutral hydrogen in the intergalactic medium (IGM) during the Epoch of Reionization (EoR, z ~ 6–10) from detections and non-detections of ...
  • Unlocking the Full Potential of Extragalactic Lyα through Its Polarization Properties 
    Eide, Marius Berge; Gronke, Max Balthasar; Dijkstra, Mark; Hayes, Matthew (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2018)
    Lyα is a powerful astrophysical probe. Not only is it ubiquitous at high redshifts, it is also a resonant line, making Lyα photons scatter. This scattering process depends on the physical conditions of the gas through which ...
  • Unresolved Fine-Scale Structure in Solar Coronal Loop-Tops 
    Scullion, Eamon; Rouppe, Van Der Voort Luc; Wedemeyer-Böhm, Sven; Antolin, Patrick (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2014)
    New and advanced space-based observing facilities continue to lower the resolution limit and detect solar coronal loops in greater detail. We continue to discover even finer substructures within coronal loop cross-sections, ...
  • Updated Design of the CMB Polarization Experiment Satellite LiteBIRD 
    Sugai, Hajime; Ade, P. A. R.; Akiba, Y; Alonso, D; Arnold, K; Aumont, J.; Austermann, J; Baccigalupi, Carlo; Banday, Anthony J.; Banerji, Ranajoy; Barreiro, R. B.; Basak, S.; Beall, J.; Beckman, S; Bersanelli, Marco; Borrill, J.; Boulanger, F.; Brown, M. L.; Bucher, Martin; Buzzelli, A; Calabrese, E.; Casas, F. J.; Challinor, A.; Chan, V.; Chinone, Y.; Cliche, J.-F.; Columbro, F; Cukierman, A; Curtis, D; Danto, P.; de Bernardis, P.; de Haan, T; De Petris, M; Dickinson, C.; Dobbs, M; Dotani, T; Duband, L.; Ducout, A.; Duff, S.; Duivenvoorden, A.; Duval, J.-M.; Ebisawa, K; Elleflot, T; Enokida, H.; Eriksen, Hans Kristian Kamfjord; Errard, J; Essinger-Hileman, T.; Finelli, Fabio; Flauger, R; Franceschet, C; Fuskeland, Unni; Ganga, K.; Gao, J.-R.; Génova-Santos, R. T.; Ghigna, T; Gomez, A; Gradziel, M. L.; Grain, J.; Grupp, F.; Gruppuso, A.; Gudmundsson, Jon E.; Halverson, Nils W.; Hargrave, P; Hasebe, T; Hasegawa, M.; Hattori, M.; Hazumi, M.; Henrot-Versillé, S.; Herranz, D.; Hill, C; Hilton, G.; Hirota, Y; Hivon, E.; Hlozek, R.; Hoang, D.-T.; Hubmayr, J.; Ichiki, K; Iida, T; Imada, H; Ishimura, K.; Ishino, H; Jaehnig, G. C.; Jones, M; Kaga, T.; Kashima, S; Kataoka, Y; Katayama, N; Kawasaki, T; Keskitalo, R.; Kibayashi, A; Kikuchi, T; Kimura, K; Kisner, T; Kobayashi, Y; Kogiso, N; Kogut, A.; Kohri, K; Komatsu, E.; Komatsu, K; Konishi, K; Krachmalnicoff, Nicoletta; Kuo, C. L.; Kurinsky, N; Kushino, A; Kuwata-Gonokami, M.; Lamagna, L; Lattanzi, M; Lee, A. T.; Linder, Eric; Maffei, B; Maino, Davide; Maki, M; Mangilli, A; Martínez-González, E.; Masi, S; Mathon, R.; Matsumura, T; Mennella, A; Migliaccio, M.; Minami, Y; Mistuda, K; Molinari, D; Montier, L; Morgante, Gianluca; Mot, B; Murata, Y.; Murphy, J. A.; Nagai, M.; Nagata, R; Nakamura, S; Namikawa, T; Natoli, P; Nerval, S.; Nishibori, T; Nishino, H.; Nomura, Yoshiko; Noviello, F; O'Sullivan, C.; Ochi, H; Ogawa, H; Ohsaki, H; Ohta, I; Okada, N; Pagano, L.; Paiella, A; Paoletti, D.; Patanchon, G.; Piacentini, F; Pisano, G; Polenta, G.; Poletti, D; Prouvé, T.; Puglisi, G; Rambaud, D; Raum, C; Realini, S; Remazeilles, M.; Roudil, G.; Rubiño-Martín, J. A.; Russel, M; Sakurai, H.; Sakurai, Y; Sandri, M; Savini, G; Scott, Douglas; Sekimoto, Y; Sherwin, B. D.; Shinozaki, K; Shiraishi, M; Shirron, P.; Signorelli, G; Smecher, G.; Spizzi, P.; Stever, S. L.; Stompor, R.; Sugiyama, S.; Suzuki, A; Suzuki, J; Switzer, E.; Takaku, R; Takakura, H; Takakura, S; Takeda, Y.; Taylor, A.; Taylor, E.; Terao, Y; Thompson, K. L.; Thorne, B; Tomasi, M.; Tomida, H; Trappe, N; Tristram, M.; Tsuji, M; Tsujimoto, M; Tucker, C.; Ullom, J.; Uozumi, S.; Utsunomiya, S; Van Lanen, J.; Vermeulen, G; Vielva, P.; Villa, F.; Vissers, M.; Vittorio, N.; Voisin, F; Walker, I; Watanabe, N; Wehus, Ingunn Kathrine; Weller, J.; Westbrook, B; Winter, B; Wollack, E.; Yamamoto, R; Yamasaki, N. Y.; Yanagisawa, M; Yoshida, T.; Yumoto, J; Zannoni, M; Zonca, A. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2020)
    Recent developments of transition-edge sensors (TESs), based on extensive experience in ground-based experiments, have been making the sensor techniques mature enough for their application on future satellite cosmic microwave ...
  • Using host galaxy spectroscopy to explore systematics in the standardization of Type Ia supernovae 
    Dixon, M.; Lidman, C.; Mould, J.; Kelsey, L.; Brout, D.; Möller, A.; Wiseman, P.; Sullivan, M.; Galbany, L.; Davis, T.M.; Vincenzi, M.; Scolnic, D.; Lewis, G.F.; Smith, M.; Kessler, R.; Duffy, A.; Taylor, E.N.; Flynn, C.; Abbott, T.M.C.; Aguena, M.; Allam, S.; Andrade-Oliveira, F.; Annis, J.; Asorey, J.; Bertin, E.; Bocquet, S.; Brooks, D.; Burke, D.L.; Carnero Rosell, A.; Carollo, D.; Carrasco Kind, M.; Carretero, J.; Costanzi, M.; da Costa, Luiz N.; Pereira, M.E.S.; Doel, P.; Everett, S.; Ferrero, Ismael; Flaugher, B.; Friedel, D.; Frieman, J.; Garcia-Bellido, J.; Gatti, M.; Gerdes, D.W.; Glazebrook, K.; Gruen, D.; Gschwend, J.; Gutierrez, G.; Hinton, S.R.; Hollowood, D.L.; Honscheid, K.; Huterer, D.; James, D.J.; Kuehn, K.; Kuropatkin, N.; Malik, U.; March, M.; Menanteau, F.; Miquel, R.; Morgan, R.; Nichol, B.; Ogando, R.L.C.; Palmese, A.; Paz-Chinchón, F.; Pieres, A.; Plazas Malagón, A.A.; Rodriguez-Monroy, M.; Romer, A.K.; Sanchez, E.; Scarpine, V.; Sevilla-Noarbe, I.; Soares-Santos, M.; Suchyta, E.; Tarle, G.; To, C.; Tucker, B.E.; Tucker, D.L.; Varga, T.N. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2022)
    ABSTRACT We use stacked spectra of the host galaxies of photometrically identified Type Ia supernovae (SNe Ia) from the Dark Energy Survey (DES) to search for correlations between Hubble diagram residuals and the ...
  • Using needlets to estimate the power spectrum 
    Ingebrigtsen, Tony Asle (Master thesis / Masteroppgave, 2010)
    The statistical analysis of the Cosmic Microwave Background radiation to make estimates of the Power Spectrum is a comutationally heavy operation, involving large covariance matrices. In this thesis I explore the possibility ...
  • Using the slope of the brightness temperature continuum as a diagnostic tool for solar ALMA observations 
    Eklund, Henrik; Szydlarski, Mikolaj; Wedemeyer, Sven (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2023)
    Context. The intensity of radiation from the solar atmosphere at millimetre wavelengths is closely related to the plasma temperature, and the formation height of the radiation is wavelength dependent. It follows from this ...
  • Using voids to unscreen modified gravity 
    Falck, Bridget Lynn; Koyama, Kazuya; Zhao, Gong-Bo; Cautun, Marius (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2018)
    The Vainshtein mechanism, present in many models of gravity, is very effective at screening dark matter haloes such that the fifth force is negligible and general relativity is recovered within their Vainshtein radii. ...
  • Validation and Interpretation of a Three-dimensional Configuration of a Magnetic Cloud Flux Rope 
    Hu, Qiang; Zhu, Chunming; He, Wen; Qiu, Jiong; Jian, Lan K.; Prasad, Avijeet (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2022)
    Abstract One strong magnetic cloud (MC) with a magnetic field magnitude reaching ∼40 nT at 1 au during 2012 June 16–17 is examined in association with a preexisting magnetic flux rope (MFR) identified on the Sun. ...
  • Variability of the slow solar wind: New insights from modelling and PSP-WISPR observations 
    Poirier, Nicolas Aurelien Corentin; Réville, Victor; Rouillard, Alexis P.; Kouloumvakos, Athanasios; Valette, Emeline (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2023)
    Aims. We analyse the signature and origin of transient structures embedded in the slow solar wind, and observed by the Wide-Field Imager for Parker Solar Probe (WISPR) during its first ten passages close to the Sun. WISPR ...
  • Velocity dispersions of clusters in the Dark Energy Survey Y3 redMaPPer catalogue 
    Wetzell, V.; Jeltema, T.E.; Hegland, B.; Everett, S.; Giles, P.A.; Wilkinson, R.; Farahi, A.; Costanzi, M.; Hollowood, D.L.; Upsdell, E.; Saro, A.; Myles, J.; Bermeo, A.; Bhargava, S.; Collins, C.A.; Cross, D.; Eiger, O.; Gardner, G.; Hilton, M.; Jobel, J.; Kelly, P.; Laubner, D.; Liddle, A.R.; Mann, R.G.; Martinez, V.; Mayers, J.; McDaniel, A.; Romer, A.K.; Rooney, P.; Sahlen, M.; Stott, J.; Swart, A.; Turner, D.J.; Viana, P. T. P; Abbott, T. M. C; Aguena, M.; Allam, S.; Andrade-Oliveira, F.; Annis, J.; Asorey, J.; Bertin, E.; Burke, D.L.; Calcino, J.; Carnero Rosell, A.; Carollo, D.; Carrasco Kind, M.; Carretero, J.; Choi, A.; Crocce, M.; da Costa, L.N.; Pereira, M. E. S; Davis, T.M.; De Vicente, J.; Desai, S.; Diehl, H.T.; Dietrich, J.P.; Doel, P.; Evrard, A.E.; Ferrero, Ismael; Fosalba, P.; Frieman, J.; García-Bellido, J.; Gaztanaga, E.; Glazebrook, K.; Gruen, D.; Gruendl, R.A.; Gschwend, J.; Gutierrez, G.; Hinton, S.R.; Honscheid, K.; James, D.J.; Kuehn, K.; Kuropatkin, N.; Lahav, O.; Lewis, G.F.; Lidman, C.; Lima, M.; Maia, M. A. G; Marshall, J.L.; Melchior, P.; Menanteau, F.; Miquel, R.; Morgan, R.; Palmese, A.; Paz-Chinchón, F.; Plazas Malagón, A.A:; Sanchez, E.; Scarpine, V.; Serrano, S.; Sevilla-Noarbe, I.; Smith, M.; Soares-Santos, M.; Suchyta, E.; Tarle, G.; Thomas, D.; Tucker, B.E.; Tucker, D.L.; Varga, T.N.; Weller, J. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2022)
    ABSTRACT We measure the velocity dispersions of clusters of galaxies selected by the red-sequence Matched-filter Probabilistic Percolation (redMaPPer) algorithm in the first three years of data from the Dark ...
  • Velocity profiles of matter and biased tracers around voids 
    Massara, Elena; Percival, Will J.; Dalal, Neal; Nadathur, Seshadri; Radinovic, Sladana; Winther, Hans Arnold; Woodfinden, Alex (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2022)
    ABSTRACT The velocity profile of galaxies around voids is a key ingredient for redshift space distortion (RSD) measurements made using the void–galaxy correlation function. In this paper, we use simulations to ...
  • Venus Observations at 40 and 90 GHz with CLASS 
    Dahal, Sumit; Brewer, Michael K.; Appel, John W.; Ali, Aamir; Bennett, Charles L.; Bustos, Ricardo; Chan, Manwei; Chuss, David T.; Cleary, Joseph; Couto, Jullianna Denes; Datta, Rahul; Denis, Kevin L.; Eimer, Joseph; Espinoza, Francisco; Essinger-Hileman, Thomas; Gothe, Dominik; Harrington, Kathleen; Iuliano, Jeffrey; Karakla, John; Marriage, Tobias A.; Novack, Sasha; Núñez, Carolina; Padilla, Ivan L.; Parker, Lucas; Petroff, Matthew A.; Reeves, Rodrigo; Rhoades, Gary; Rostem, Karwan; Valle, Deniz A. N.; Watts, Duncan; Weiland, Janet L.; Wollack, Edward J.; Xu, Zhilei (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
    Abstract Using the Cosmology Large Angular Scale Surveyor, we measure the disk-averaged absolute Venus brightness temperature to be 432.3 ± 2.8 K and 355.6 ± 1.3 K in the Q and W frequency bands centered at 38.8 ...
  • VLT/X-Shooter spectroscopy of the afterglow of the Swift GRB 130606A: Chemical abundances and reionisation at z ~ 6 
    Hartoog, O. E.; Malesani, D; Fynbo, J.P.U.; Goto, T; Krühler, T.; Vreeswijk, P. M.; De Cia, A.; Xu, D.; Møller, P.; Covino, S; D'Elia, V; Flores, H; Goldoni, P.; Hjorth, Jens; Jakobsson, P.; Krogager, J.-K.; Kaper, L.; Ledoux, C.; Levan, A. J.; Milvang-Jensen, B; Sollerman, J.; Sparre, M.; Tagliaferri, G; Tanvir, N. R.; de Ugarte Postigo, A.; Vergani, S. D.; Wiersema, K; Datson, J.; Salinas, R; Mikkelsen, Kristin; Aghanim, N. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2015)
    Context: The reionisation of the Universe is a process that is thought to have ended around z ~ 6, as inferred from spectroscopy of distant bright background sources, such as quasars (QSO) and gamma-ray burst (GRB) afterglows. ...
  • Vortex flows in the solar chromosphere: I. Automatic detection method 
    Kato, Yoshiaki; Wedemeyer, Sven (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2017)
    Solar “magnetic tornadoes” are produced by rotating magnetic field structures that extend from the upper convection zone and the photosphere to the corona of the Sun. Recent studies show that these kinds of rotating features ...