8 papers
Emergence of Small-Scale Magnetic Loops in the Quiet Sun Internetwork
R. Centeno, H. Socas-Navarro, B. Lites +11
We study the emergence of magnetic flux at very small spatial scales (less than 2 arcsec) in the quiet Sun internetwork. To this aim, a time series of spectropolarimetric maps was…
Spectral Line Selection for HMI: A Comparison of Fe I 6173 and Ni I 6768
A. A. Norton, J. Pietarila Graham, R. K. Ulrich +8
We present a study of two spectral lines, Fe I 6173 Angstroms and Ni I 6768 Angstroms, that were candidates to be used in the Helioseismic and Magnetic Imager (HMI) for observing D…
Evidence for Fine Structure in the Chromospheric Umbral Oscillation
R. Centeno, H. Socas-Navarro, M. Collados +1
Novel spectro-polarimetric observations of the \ion{He}{1} multiplet are used to explore the dynamics of the chromospheric oscillation above sunspot umbrae. The results presented h…
Motivation and Initial Results from SPINOR in the Near Infrared
H. Socas-Navarro, D. Elmore, W. Lites
SPINOR is a new spectro-polarimeter that will serve as a facility instrument for the Dunn Solar Telescope at the National Solar Observatory. This instrument is capable of achromati…
Shocks in the Quiet Solar Photosphere: A Rather Common Occurrence
H. Socas-Navarro, R. Manso
We present observations of the quiet solar photosphere in the \ion{Fe}{1} lines at 6302 Åwhere at least four different spatial locations exhibit upwards-directed supersonic flows.…
Strategies for Spectral Profile Inversion using Artificial Neural Networks
H. Socas-Navarro
This paper explores three different strategies for the inversion of spectral lines (and their Stokes profiles) using artificial neural networks. It is shown that a straightforward…