Ultraviolet emission of unipolar active regions and a relation between its intensity and magnetic flux decay rate
Article Sidebar
PDF downloads: 59
Main Article Content
Abstract
This study uses data on 617 active regions (ARs) acquired by the Solar Dynamics Observatory. Unipolar ARs exhibit a lower density of He II 304 Å ultraviolet (UV) emission above sunspots as compared to the ARs of other types. Bipolar and multipolar ARs, regardless of their magnetic flux, show a similar density of UV emission above sunspots. In contrast, in unipolar ARs, the UV emission density increases with increasing magnetic flux. This relationship can be used to estimate the magnetic flux values from the maps of UV emission density. Additionally, the total unsigned magnetic flux decay rate is in moderate correlation with the UV emission above sunspots. This correlation may help to explain the phenomenon of slow-decaying unipolar ARs.
Supporting Agencies
The work was supported by the state assignment No. 122022400224-7
Downloads
Article Details
Copyright (c) 2025 Andrey Plotnikov
The metadata for this submission is licensed under a Creative Commons Attribution 4.0 International License.
Copyright and publishing rights for texts published in Acta Astrophysica Taurica is retained by the authors, with first publication rights granted to the journal.Texts are free to use with proper attribution and link to the licensing (Creative Commons Attribution 4.0 International).
References
Astropy Collaboration, Price-Whelan A.M., Lim P.L., et al., 2022. Astrophys. J., vol. 935, no. 2, p. 167.
Bobra M.G., Sun X., Hoeksema J.T., et al., 2014. Solar. Phys., vol. 289, no. 9, pp. 3549–3578.
Harris C.R., Millman K.J., van der Walt S.J., et al., 2020. Nature, vol. 585, no. 7825, pp. 357–362.
Hunter J.D., 2007. Comput. Sci. Eng., vol. 9, no. 3, pp. 90–95.
Kaiser M.L., Kucera T.A., Davila J.M., et al., 2008. Space Sci. Rev., vol. 136, no. 1–4, pp. 5–16.
Müller D., Marsden R.G., St. Cyr O.C., Gilbert H.R., Solar Orbiter Team, 2013. Solar. Phys., vol. 285, no. 1–2, pp. 25–70.
Norton A.A., Jones E.H., Linton M.G., Leake J.E., 2017. Astrophys. J., vol. 842, no. 1, p. 3.
Pesnell W.D., Thompson B.J., Chamberlin P.C., 2012. Solar. Phys., vol. 275, no. 1–2, pp. 3–15.
Plotnikov A.A., Abramenko V.I., Kutsenko A.S., 2023. Mon. Not. Roy. Astron. Soc., vol. 521, no. 2, pp. 2187–2195.
Scherrer P.H., Schou J., Bush R.I., et al., 2012. Solar. Phys., vol. 275, no. 1–2, pp. 207–227.
Schrijver C.J., 1987. Astron. Astrophys., vol. 180, no. 1–2, pp. 241–252.
The SunPy Community, Barnes W.T., Bobra M.G., et al., 2020. Astrophys. J., vol. 890, p. 68.
Ugarte-Urra I., Upton L., Warren H.P., Hathaway D.H., 2015. Astrophys. J., vol. 815, no. 2, p. 90.
Virtanen P., Gommers R., Oliphant T.E., et al., 2020. Nature Methods, vol. 17, pp. 261–272.