Delta på disputasen
PhD disputasen og prøveforelesningen vil foregå 100% fysisk. Rommet åpnes for deltakelse like før disputasen starter, og stenger for nye deltakere omtrent 15 minutter etter at disputasen har startet.
Delta på prøveforelesning - 4. juni kl. 10:15 (Aud. 209, Svein Rosselands Hus)
"Where are all the stellar prominence eruptions? Observational limitation or gap in theoretical understanding?"
Kreeringssammendrag
Avhandlingen viser at magnetisk omkobling, der motsatt rettede magnetfeltlinjer kobles sammen og frigjør energi, driver jetstråler i solatmosfæren. Vi har oppdaget at sjokkbølger kan utløse magnetisk omkobling, og ved å følge en tilbakevendende omkoblingsprosess over 3,5 timer fanger vi hele livsløpet til én hendelse: hvordan den oppstår, utvikler seg og forsvinner.
Hovedfunn:
The Sun's outer atmosphere, the corona, is millions of degrees hotter than its surface, a long-standing puzzle in solar physics. Understanding what feeds the corona with energy and mass is a central question, and small-scale energy releases and jets in the lower atmosphere are thought to play a key role.
This thesis shows that a process called magnetic reconnection drives these jets throughout the solar atmosphere. Magnetic reconnection occurs when oppositely directed magnetic field lines reconnect and release energy, similar to a stretched slingshot snapping back.
We discovered that reconnection can start in previously unrecognised ways: shockwaves travelling through the atmosphere can trigger it, suggesting reconnection may occur more often than previously thought.
We also tracked a recurrent reconnection process lasting over 3.5 hours, far longer than the minutes typically observed. Because this system underwent many cycles, we could follow the full life story of a single reconnection event linked to a large jet: how it begins, grows, and eventually fades.
Taken together, these results suggest that magnetic reconnection, operating across atmospheric scales and interacting with shockwaves, may play an important role in coronal heating, bringing us a step closer to solving one of the Sun's biggest mysteries.
.png)