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Visar resultat 1 - 5 av 6 avhandlingar som matchar ovanstående sökkriterier.

1. 1. Measuring the solar atmosphere

   Författare :Jaime de la Cruz Rodríguez; Göran Scharmer; Dan Kiselman; Mats Carlsson; Gianna Cauzzi; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Sun; Chromosphere; Spectropolarimetry; Solar observations; Spectral lines; Solar magnetic fields; Astronomy; Astronomi; Astronomy; astronomi;

   Sammanfattning : The new CRISP filter at the Swedish 1-m Solar Telescope provides opportunities for observing the solar atmosphere with unprecedented spatial resolution and cadence. In order to benefit from the high quality of observational data from this instrument, we have developed methods for calibrating and restoring polarized Stokes images, obtained at optical and near infrared wavelengths, taking into account field-of-view variations of the filter properties. LÄS MER

3. 2. Constraints on the gas temperature in the solaratmosphere from multiwavelength inversions

   Författare :João Manuel da Silva Santos; Jaime de la Cruz Rodríguez; Andreas Korn; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Sun; chromosphere; ALMA; inversions; Astronomy; astronomi;

   Sammanfattning : In this Licentiate thesis I review the properties of the solar atmosphere and the diagnostic value ofdifferent spectral lines in the visible and ultraviolet (UV) along with the millimeter (mm) continua in theelectromagnetic spectrum of the Sun.While the solar atmosphere has been routinely observed in high-resolution from ground-based opti-cal telescopes such as the Swedish Solar Telescope (SST), and more recently in the UV from space tele-scopes such as the Interface Region Imaging Spectrograph (IRIS), radio observations lag behind despitetheir great usefulness. LÄS MER

4. 3. Exploring the diagnostic value of He I D3 in the solar chromosphere

   Författare :Tine Libbrecht; Jaime de la Cruz Rodríguez; Paul Barklem; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Astronomy; astronomi;

   Sammanfattning : .... LÄS MER

5. 4. The diagnostic potential of the He I D3 spectral line in the solar atmosphere

   Författare :Tine Libbrecht; Jaime de la Cruz Rodríguez; Jorrit Leenaarts; Göran Scharmer; Valentín Martínez Pillet; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Sun; Line formation; Chromosphere; Spectro-Polarimetry; Flares; Reconnection; Astronomy; astronomi;

   Sammanfattning : The research question of my PhD is in a way a simple one: what can observations of the He I D3 line teach us about the solar chromosphere? This optical spectral line at 5876 Å is generally formed in the upper chromosphere, and is sensitive to the local magnetic field. The He I D3 line is also indirectly sensitive to heating of the transition region and corona, since it is resulting from a transition that occurs between levels in the triplet system of neutral helium. LÄS MER

7. 5. Constraining magnetic heating in the solar chromosphere

   Författare :Roberta Morosin; Jaime de la Cruz Rodríguez; Elena Khomenko; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Sun; chromosphere; magnetic fields; spectropolarimetry; Astronomy; astronomi;

   Sammanfattning : The chromospheric and coronal heating problems remain one of the foremost open questions in solar and stellar physics: how are the outer layers of the Sun heated from a few thousand kelvin in the photosphere to the million-degree corona? Radiation alone is not capable of transporting the required energy to explain observations from the inner layers. Phenomena associated with the presence of magnetic fields could provide the missing energy. LÄS MER