515 research outputs found

    Solar polarimetry through the K I lines at 770 nm

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    We characterize the K I D1 & D2 lines in order to determine whether they could complement the 850 nm window, containing the Ca II infrared triplet lines and several Zeeman sensitive photospheric lines, that was studied previously. We investigate the effect of partial redistribution on the intensity profiles, their sensitivity to changes in different atmospheric parameters, and the spatial distribution of Zeeman polarization signals employing a realistic magnetohydrodynamic simulation. The results show that these lines form in the upper photosphere at around 500 km and that they are sensitive to the line of sight velocity and magnetic field strength at heights where neither the photospheric lines nor the Ca II infrared lines are. However, at the same time, we found that their sensitivity to the temperature essentially comes from the photosphere. Then, we conclude that the K I lines provide a complement to the lines in the 850 nm window for the determination of atmospheric parameters in the upper photosphere, especially for the line of sight velocity and the magnetic field.Comment: 10 pages, 9 figures, main journal publicatio

    Study of the polarization produced by the Zeeman effect in the solar Mg I b lines

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    The next generation of solar observatories aim to understand the magnetism of the solar chromosphere. Therefore, it is crucial to understand the polarimetric signatures of chromospheric spectral lines. For this purpose, we here examine the suitability of the three Fraunhofer Mg I b1, b2, and b4 lines at 5183.6, 5172.7, and 5167.3 A, respectively. We start by describing a simplified atomic model of only 6 levels and 3 line transitions for computing the atomic populations of the 3p-4s (multiplet number 2) levels involved in the Mg I b line transitions assuming non-local thermodynamic conditions and considering only the Zeeman effect using the field-free approximation. We test this simplified atom against more complex ones finding that, although there are differences in the computed profiles, they are small compared with the advantages provided by the simple atom in terms of speed and robustness. After comparing the three Mg I lines, we conclude that the most capable one is the b2 line as b1 forms at similar heights and always show weaker polarization signals while b4 is severely blended with photospheric lines. We also compare Mg I b2 with the K I D1 and Ca II 8542 A lines finding that the former is sensitive to the atmospheric parameters at heights that are in between those covered by the latter two lines. This makes Mg I b2 an excellent candidate for future multi-line observations that aim to seamlessly infer the thermal and magnetic properties of different features in the lower solar atmosphere.Comment: 14 pages, 11 figures, and 5 table

    Development and Validation of the Jordanian Diabetic Health Literacy Questionnaire: Enhancing Diabetes Management in Arabic-Speaking Populations

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    (1) Background: Amidst the global rise in type 2 diabetes mellitus (T2DM), effective management of the disease has become increasingly important. Health literacy, particularly in non-English speaking populations, plays a crucial role in this management. To address the lack of suitable tools for Arabic-speaking diabetic patients, this study developed and validated the Jordanian Diabetic Health Literacy Questionnaire (JDHLQ). (2) Methods: A sample of 400 diabetic patients from Jordan, with a balance in gender, age, and educational background, was recruited from an endocrinology outpatient clinic. The JDHLQ, consisting of informative and communicative sections, underwent rigorous validation. Utilizing principal component analysis and Rasch analysis, the JDHL's reliability and validity were evaluated. (3) Results: The results showed moderate proficiency in understanding and communicating diabetes-related information and confirmed the reliability and validity of the JDHLQ. (4) Conclusions: These findings emphasize the importance of culturally appropriate health literacy tools in enhancing patient understanding, engagement, and overall management of T2DM in Arabic-speaking communities

    Chromospheric polarimetry through multi-line observations of the 850 nm spectral region III: Chromospheric jets driven by twisted magnetic fields

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    We investigate the diagnostic potential of the spectral lines at 850 nm for understanding the magnetism of the lower atmosphere. For that purpose, we use a newly developed 3D simulation of a chromospheric jet to check the sensitivity of the spectral lines to this phenomenon as well as our ability to infer the atmospheric information through spectropolarimetric inversions of noisy synthetic data. We start comparing the benefits of inverting the entire spectrum at 850 nm versus only the Ca II 8542 A spectral line. We found a better match of the input atmosphere for the former case, mainly at lower heights. However, the results at higher layers were not accurate. After several tests, we determined that we need to weight more the chromospheric lines than the photospheric ones in the computation of the goodness of the fit. The new inversion configuration allows us to obtain better fits and consequently more accurate physical parameters. Therefore, to extract the most from multi-line inversions, a proper set of weights needs to be estimated. Besides that, we conclude again that the lines at 850 nm, or a similar arrangement with Ca II 8542 A plus Zeeman sensitive photospheric lines, poses the best observing configuration for examining the thermal and magnetic properties of the lower solar atmosphere.Comment: 14 pages, 11 figure

    Increasing the Fine Structure Visibility of the Hinode SOT Ca II H Filtergrams

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    We present the improved so-called Madmax (OMC) operator selecting maxima of convexities computed in multiple directions around each pixel rewritten in MatLab and shown to be very efficient for pattern recognition. The aim of the algorithm is to trace the bright hair-like features (for ex. chromospheric thin jets or spicules) of solar ultimate observations polluted by a noise of different origins. This popular spatial operator uses the second derivative in the optimally selected direction for which its absolute value has a maximum value. Accordingly, it uses the positivity of the resulting intensity signal affected by a superposed noise. The results are illustrated using a test artificially generated image and real SOT (Hinode) images are also used, to make your own choice of the sensitive parameters to use in improving the visibility of images.Comment: 12 pages, 3 figurs, submitted in Solar Physic

    Study of the polarization produced by the Zeeman effect in the solar MgI b lines

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    The next generation of solar observatories aim to understand the magnetism of the solar chromosphere. Therefore, it is crucial to understand the polarimetric signatures of chromospheric spectral lines. For this purpose, we here examine the suitability of the three Fraunhofer MgI b1, b2, and b4 lines at 5183.6, 5172.7, and 5167.3 Å, respectively. We start by describing a simplified atomic model of only six levels and three line transitions for computing the atomic populations of the 3p-4s (multiplet number 2) levels involved in the Mg I b line transitions assuming non-local thermodynamic conditions and considering only the Zeeman effect using the field-free approximation. We test this simplified atom against more complex ones finding that, although there are differences in the computed profiles, they are small compared with the advantages provided by the simple atom in terms of speed and robustness. After comparing the three MgI lines, we conclude that the most capable one is the b2 line as b1 forms at similar heights and always shows weaker polarization signals, while b4 is severely blended with photospheric lines. We also compare Mg I b2 with the KI D1 and Ca II 8542 Å lines finding that the former is sensitive to the atmospheric parameters at heights that are in between those covered by the latter two lines. This makes MgI b2 an excellent candidate for future multiline observations that aim to seamlessly infer the thermal and magnetic properties of different features in the lower solar atmosphere. © 2018 The Author(s).We appreciate the help of the anonymous referee that, during the revision process, provided us comments and suggestions that allowed improving the manuscript. CQN acknowledges the support of the ISAS/JAXA International Top Young Fellowship and the JSPS KAKENHI grant number 18K13596. The SUNRISE-3 project is supported in Japan by the funding from ISAS/JAXA for the smallscale program for novel solar observations and the JSPS KAKENHI grant numbers 18H03723 and 18H05234. This research was supported by the Research Council of Norway through its Centres of Excellence scheme, project number 262622. This work has also been supported by Spanish Ministry of Economy and Competitiveness through the project ESP-2016-77548-C5-1-R. DOS also acknowledges financial support through the Ramon y Cajal fellowships
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