Manel Collados

Learn More
An attractive diagnostic tool for investigating the magnetism of the solar chro-mosphere is the observation and theoretical modeling of the Hanle and Zeeman effects in spicules, as shown in this letter for the first time. Here we report on spectropolarimetric observations of solar chromospheric spicules in the He i 10830Å multiplet and on their theoretical(More)
Magnetic fields play a key role in most astrophysical systems, from the Sun to active galactic nuclei. They can be studied through their effects on atomic energy levels, which produce polarized spectral lines. In particular, anisotropic radiation 'pumping' processes (which send electrons to higher atomic levels) induce population imbalances that are(More)
We report novel spectropolarimetric observations of sunspots carried out with the Tenerife Infrared Polarimeter (TIP) in a near-IR spectral region around 15410Å, which is known to contain two groups of prominent OH lines that show circular polarization signals of opposite polarity. Surrounding these well-known OH lines, we have discovered the presence of CN(More)
Flares and X-ray jets on the Sun arise in active regions where magnetic flux emerges from the solar interior amd interacts with the ambient magnetic field. The interactions are believed to occur in electric current sheets separating regions of opposite magnetic polarity. The current sheets located in the corona or upper chromosphere have long been thought(More)
We report two-dimensional MHD simulations which demonstrate that pho-tospheric 5-min oscillations can leak into the chromosphere inside small-scale vertical magnetic flux tubes. The results of our numerical experiments are compatible with those inferred from simultaneous spectropolarimetric observations of the photosphere and chromosphere obtained with the(More)