Brightness of Solar Magnetic Elements As a Function of Magnetic Flux at High Spatial Resolution

Journal Article · Wed Mar 01 04:00:00 EST 2017 · Astrophysical Journal, Supplement Series

DOI:https://doi.org/10.3847/1538-4365/229/1/12· OSTI ID:22872844

Kahil, F.; Riethmüller, T. L.

We investigate the relationship between the photospheric magnetic field of small-scale magnetic elements in the quiet-Sun (QS) at disk center and the brightness at 214, 300, 313, 388, 397, and 525.02 nm. To this end, we analyzed spectropolarimetric and imaging time series acquired simultaneously by the Imaging Magnetograph eXperiment magnetograph and the SuFI filter imager on board the balloon-borne observatory SUNRISE during its first science flight in 2009, with high spatial and temporal resolution. We find a clear dependence of the contrast in the near ultraviolet and the visible on the line-of-sight component of the magnetic field, B {sub LOS}, which is best described by a logarithmic model. This function effectively represents the relationship between the Ca ii H-line emission and B {sub LOS} and works better than the power-law fit adopted by previous studies. This, along with the high contrast reached at these wavelengths, will help with determining the contribution of small-scale elements in the QS to the irradiance changes for wavelengths below 388 nm. At all wavelengths, including the continuum at 525.40 nm, the intensity contrast does not decrease with increasing B {sub LOS}. This result also strongly supports the fact that SUNRISE has resolved small strong magnetic field elements in the internetwork, resulting in constant contrasts for large magnetic fields in our continuum contrast at 525.40 nm versus the B {sub LOS} scatterplot, unlike the turnover obtained in previous observational studies. This turnover is due to the intermixing of the bright magnetic features with the dark intergranular lanes surrounding them.

• OSTI ID: 22872844
• Journal Information: Astrophysical Journal, Supplement Series, Journal Name: Astrophysical Journal, Supplement Series Journal Issue: 1 Vol. 229; ISSN 0067-0049; ISSN APJSA2
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
BRIGHTNESS
IMAGES
MAGNETIC FIELDS
MAGNETIC FLUX
PHOTOSPHERE
RADIANT FLUX DENSITY
SCATTERPLOTS
SPATIAL RESOLUTION
SUN
TELESCOPES
ULTRAVIOLET RADIATION
WAVELENGTHS