{"id":2217,"date":"2024-03-04T10:03:21","date_gmt":"2024-03-04T09:03:21","guid":{"rendered":"https:\/\/pepsi.aip.de\/?p=2217"},"modified":"2024-09-02T10:09:24","modified_gmt":"2024-09-02T09:09:24","slug":"testing-pulsation-diagnostics-in-the-rapidly-oscillating-magnetic-ap-star-%ce%b3-equ","status":"publish","type":"post","link":"https:\/\/pepsi.aip.de\/?p=2217","title":{"rendered":"Testing pulsation diagnostics in the rapidly oscillating magnetic Ap star gamma Equ"},"content":{"rendered":"\n\n\n

Pulsations of rapidly oscillating Ap stars and their interaction with the stellar magnetic field have not been studied in the near-infrared (near-IR) region despite the benefits these observations offer compared to visual wavelengths. The main advantage of the near-IR is the quadratic dependence of the Zeeman effect on the wavelength, as opposed to the linear dependence of the Doppler effect.<\/p>\n

To test pulsation diagnostics of roAp stars in the near-IR, we investigated the pulsation behaviour of one of the brightest magnetic roAp stars, \u03b3 Equ, which possesses a strong surface magnetic field of the order of several kilogauss and exhibits magnetically split spectral lines in its spectra.<\/p>\n

The profile shapes of both studied magnetically split spectral lines in H-band vary in a rather complex manner probably due to a significant decrease in the strength of the longitudinal field component and an increase in the strength of the transverse field components over the last decade. A mean magnetic field modulus of 3.9 kG was determined for the Zeeman triplet Fe I at 1563.63 nm, whereas for the pseudo- doublet Ce III at 1629.2 nm we observe a much lower value of only about 2.9 kG. For comparison, a mean field modulus of 3.4 kG was determined using the Zeeman doublet Fe II at 6249.25 \u00c5 in optical PEPSI spectra recorded just about two weeks before the 2022 CRIRES+ observations. Different effects may lead to the differences in the field modulus values. The measurements of the mean magnetic field modulus in different pulsational phase bins suggest a field modulus variability of 32 G for the Zeeman triplet Fe I and 102 G for the pseudo-doublet Ce III.<\/p>\n\n\n\n

\"\"<\/a>
Zeeman doublet Fe II at 6149.25 \u00c5 used for measuring the mean magnetic field modulus in observations obtained in different years using different instruments. Right: Comparison of the shape of line profiles of Zeeman triplet Fe I 1563.63 nm from different years in near-IR region.<\/figcaption><\/figure>\n\n\n\n

Read more: J\u00e4rvinen et al. 2024, A&A 683, A66<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

Pulsations of rapidly oscillating Ap stars and their interaction with the stellar magnetic field have not been studied in the near-infrared (near-IR) region despite the benefits these observations offer compared to visual wavelengths. The main advantage of the near-IR is the quadratic dependence of the Zeeman effect on the wavelength, as opposed to the linear … Continue reading Testing pulsation diagnostics in the rapidly oscillating magnetic Ap star gamma Equ<\/span> →<\/span><\/a><\/p>\n","protected":false},"author":5,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[11],"tags":[],"class_list":["post-2217","post","type-post","status-publish","format-standard","hentry","category-publications"],"_links":{"self":[{"href":"https:\/\/pepsi.aip.de\/index.php?rest_route=\/wp\/v2\/posts\/2217","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/pepsi.aip.de\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/pepsi.aip.de\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/pepsi.aip.de\/index.php?rest_route=\/wp\/v2\/users\/5"}],"replies":[{"embeddable":true,"href":"https:\/\/pepsi.aip.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2217"}],"version-history":[{"count":6,"href":"https:\/\/pepsi.aip.de\/index.php?rest_route=\/wp\/v2\/posts\/2217\/revisions"}],"predecessor-version":[{"id":2224,"href":"https:\/\/pepsi.aip.de\/index.php?rest_route=\/wp\/v2\/posts\/2217\/revisions\/2224"}],"wp:attachment":[{"href":"https:\/\/pepsi.aip.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2217"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/pepsi.aip.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2217"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/pepsi.aip.de\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2217"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}