Bibcode
Guglielmino, S. L.; Martínez-Pillet, V.; Bonet, J. A.; del Toro Iniesta, J. Carlos; Bellot Rubio, L. R.; Solanki, S. K.; Schmidt, W.; Gandorfer, A.; Barthol, P.; Knölker, M.
Referencia bibliográfica
The Astrophysical Journal, Volume 745, Issue 2, article id. 160 (2012).
Fecha de publicación:
2
2012
Revista
Número de citas
40
Número de citas referidas
34
Descripción
We report on the photospheric evolution of an intermediate-scale (≈4
Mm footpoint separation) magnetic bipole, from emergence to decay,
observed in the quiet Sun at high spatial (0farcs3) and temporal (33 s)
resolution. The observations were acquired by the Imaging Magnetograph
Experiment imaging magnetograph during the first science flight of the
SUNRISE balloon-borne solar observatory. The bipole flux content is 6
× 1017 Mx, representing a structure bridging the gap
between granular scale bipoles and the smaller ephemeral regions.
Footpoints separate at a speed of 3.5 km s-1 and reach
a maximum distance of 4.5 Mm before the field dissolves. The evolution
of the bipole is revealed to be very dynamic: we found a proper motion
of the bipole axis and detected a change of the azimuth angle of 90°
in 300 s, which may indicate the presence of some writhe in the emerging
structure. The overall morphology and behavior are in agreement with
previous analyses of bipolar structures emerging at the granular scale,
but we also found several similarities with emerging flux structures at
larger scales. The flux growth rate is 2.6 × 1015 Mx
s-1, while the mean decay rate is one order of
magnitude smaller. We describe in some detail the decay phase of the
bipole footpoints that includes break up into smaller structures, and
interaction with preexisting fields leading to cancellation, but it
appears to be dominated by an as-yet unidentified diffusive process that
removes most of the flux with an exponential flux decay curve. The
diffusion constant (8 × 102 km2
s-1) associated with this decay is similar to the
values used to describe the large-scale diffusion in flux transport
models.
Proyectos relacionados
Simulación Numérica de Procesos Astrofísicos
La simulación numérica mediante códigos complejos de ordenador es una herramienta fundamental en la investigación física y en la técnica desde hace décadas. El crecimiento vertiginoso de las capacidades informáticas junto con el avance notable de la matemática numérica ha hecho accesible a los centros de investigación de tamaño medio
Daniel Elías
Nóbrega Siverio
Magnestismo Solar y Estelar
Los campos magnéticos son uno de los ingredientes fundamentales en la formación de estrellas y su evolución. En el nacimiento de una estrella, los campos magnéticos llegan a frenar su rotación durante el colapso de la nube molecular, y en el fin de la vida de una estrella, el magnetismo puede ser clave en la forma en la que se pierden las capas
Tobías
Felipe García