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dc.date.accessioned2019-04-17T10:09:22Z
dc.date.available2019-04-17T10:09:22Z
dc.date.created2019-01-22T12:06:22Z
dc.date.issued2018
dc.identifier.citationBrajša, R. Sudar, D. Benz, A. O. Skokić, I. Bárta, M. De Pontieu, Bart Walter Kim, S. Kobelski, A. Kuhar, M. Shimojo, M. Wedemeyer, Sven White, S. Yagoubov, P. Yan, Y. . First analysis of solar structures in 1.21 mm full-disc ALMA image of the Sun. Astronomy and Astrophysics. 2018, 613
dc.identifier.urihttp://hdl.handle.net/10852/67715
dc.description.abstractContext: Various solar features can be seen in emission or absorption on maps of the Sun in the millimetre and submillimetre wavelength range. The recently installed Atacama Large Millimetre/submillimetre Array (ALMA) is capable of observing the Sun in that wavelength range with an unprecedented spatial, temporal and spectral resolution. To interpret solar observations with ALMA, the first important step is to compare solar ALMA maps with simultaneous images of the Sun recorded in other spectral ranges. Aims: The first aim of the present work is to identify different structures in the solar atmosphere seen in the optical, infrared, and EUV parts of the spectrum (quiet Sun, active regions, prominences on the disc, magnetic inversion lines, coronal holes and coronal bright points) in a full-disc solar ALMA image. The second aim is to measure the intensities (brightness temperatures) of those structures and to compare them with the corresponding quiet Sun level. Methods: A full-disc solar image at 1.21 mm obtained on December 18, 2015, during a CSV-EOC campaign with ALMA is calibrated and compared with full-disc solar images from the same day in Hα line, in He I 1083 nm line core, and with various SDO images (AIA at 170 nm, 30.4 nm, 21.1 nm, 19.3 nm, and 17.1 nm and HMI magnetogram). The brightness temperatures of various structures are determined by averaging over corresponding regions of interest in the calibrated ALMA image. Results: Positions of the quiet Sun, active regions, prominences on the disc, magnetic inversion lines, coronal holes and coronal bright points are identified in the ALMA image. At the wavelength of 1.21 mm, active regions appear as bright areas (but sunspots are dark), while prominences on the disc and coronal holes are not discernible from the quiet Sun background, despite having slightly less intensity than surrounding quiet Sun regions. Magnetic inversion lines appear as large, elongated dark structures and coronal bright points correspond to ALMA bright points. Conclusions: These observational results are in general agreement with sparse earlier measurements at similar wavelengths. The identification of coronal bright points represents the most important new result. By comparing ALMA and other maps, it was found that the ALMA image was oriented properly and that the procedure of overlaying the ALMA image with other images is accurate at the 5 arcsec level. The potential of ALMA for physics of the solar chromosphere is emphasised.en_US
dc.languageEN
dc.publisherEDP Sciences
dc.titleFirst analysis of solar structures in 1.21 mm full-disc ALMA image of the Sunen_US
dc.typeJournal articleen_US
dc.creator.authorBrajša, R.
dc.creator.authorSudar, D.
dc.creator.authorBenz, A. O.
dc.creator.authorSkokić, I.
dc.creator.authorBárta, M.
dc.creator.authorDe Pontieu, Bart Walter
dc.creator.authorKim, S.
dc.creator.authorKobelski, A.
dc.creator.authorKuhar, M.
dc.creator.authorShimojo, M.
dc.creator.authorWedemeyer, Sven
dc.creator.authorWhite, S.
dc.creator.authorYagoubov, P.
dc.creator.authorYan, Y.
cristin.unitcode185,15,3,40
cristin.unitnameRosseland senter for solfysikk
cristin.ispublishedtrue
cristin.fulltextoriginal
cristin.qualitycode2
dc.identifier.cristin1662884
dc.identifier.bibliographiccitationinfo:ofi/fmt:kev:mtx:ctx&ctx_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.jtitle=Astronomy and Astrophysics&rft.volume=613&rft.spage=&rft.date=2018
dc.identifier.jtitleAstronomy and Astrophysics
dc.identifier.volume613
dc.identifier.pagecount9
dc.identifier.doihttp://dx.doi.org/10.1051/0004-6361/201730656
dc.identifier.urnURN:NBN:no-70867
dc.type.documentTidsskriftartikkelen_US
dc.type.peerreviewedPeer reviewed
dc.source.issn0004-6361
dc.identifier.fulltextFulltext https://www.duo.uio.no/bitstream/handle/10852/67715/1/aa30656-17.pdf
dc.type.versionPublishedVersion
cristin.articleidA17
dc.relation.projectNFR/262622


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