An astrophysical interpretation of the remarkable g-mode frequency groups of the rapidly rotating γ Dor star, KIC 5608334. Issue 2 (29th March 2018)

• Record Type: Journal Article
• Authors: Saio, Hideyuki; Bedding, Timothy R; Kurtz, Donald W; Murphy, Simon J; Antoci, Victoria; Shibahashi, Hiromoto; Li, Gang; Takata, Masao
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 477:Issue 2(2018)
• Page Start: 2183
• Page End: 2195
• Publication Date: 2018-03-29
• Subjects: asteroseismology -- stars: individual: (KIC 5608334) -- stars: oscillations -- stars: rotation -- stars: variables; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/sty784
• Languages: English
• ISSNs: 0035-8711

Abstract

Abstract: The Fourier spectrum of the γ-Dor variable KIC 5608334 shows remarkable frequency groups at ∼3, ∼6, ∼9, and 11–12 d −1 . We explain the four frequency groups as prograde sectoral g modes in a rapidly rotating star. Frequencies of intermediate-to-high radial order prograde sectoral g modes in a rapidly rotating star are proportional to | m | (i.e. ν ∝ | m |) in the corotating frame as well as in the inertial frame. This property is consistent with the frequency groups of KIC 5608334 as well as the period versus period-spacing relation present within each frequency group, if we assume a rotation frequency of 2.2 d −1, and that each frequency group consists of prograde sectoral g modes of | m | = 1, 2, 3, and 4, respectively. In addition, these modes naturally satisfy near-resonance conditions ν i ≈ ν j + ν k with mi = mj + mk . We even find exact resonance frequency conditions (within the precise measurement uncertainties) in many cases, which correspond to combination frequencies.