Period spacings of $\gamma$ Doradus pulsators in the Kepler field: detection methods and application to 22 slow rotators

Abstract

In $\gamma$ Doradus stars, the g-mode period spacing shows an approximately linear relation with period. The slope is a new asteroseismic diagnostic, related to the rotation rate and the azimuthal order $m$. We report two automated methods, the `moving-window Fourier transform' and the `cross-correlation', to detect and measure the period spacings based on four-year light curves from the \textit{Kepler} satellite. The results show that the cross-correlation method performs better at detecting the period spacings and their slopes. In this paper, we apply our method to 22 $\gamma$ Dor stars with g-mode multiplets split by rotation. The rotation periods are similar to the g-mode period spacings, causing the multiplets to overlap. To clarify the overlapping patterns, we use the échelle diagram and introduce a `copy-shift' diagram to discern and measure the splittings. The first observational relation between slopes and splittings is shown. The slope deviates from zero when the splitting increases, as the theory predicts. We found that what appears to be rotational splittings in two stars is in fact caused by two nearly-identical overlapping patterns from binaries.

arXiv comment38 pages, 66 figures, Accepted by MNRAS

References in corpus (33)

• emcee: The MCMC Hammer
• GYRE: An open-source stellar oscillation code based on a new Magnus Multiple Shooting Scheme
• Probing the properties of convective cores through g modes: high-order g modes in SPB and gamma Doradus stars
• Rotational velocities of A-type stars. III. Velocity distributions
• Gamma Doradus Stars: Defining a New Class of Pulsating Variables
• Asteroseismic measurement of surface-to-core rotation in a main sequence A star, KIC 11145123
• The interior rotation of a sample of gamma Doradus stars from ensemble modelling of their gravity mode period spacings
• Asteroseismic measurement of slow, nearly-uniform surface-to-core rotation in the main sequence F star KIC 9244992
• Solar-like oscillations in eta Boo
• Signatures of internal rotation discovered in the Kepler data of five slowly pulsating B stars
• A unifying explanation of complex frequency spectra of gamma Dor, SPB and Be stars: combination frequencies and highly non-sinusoidal light curves
• A new asteroseismic diagnostic for internal rotation in $\gamma$ Doradus stars
• Theory and evidence of global Rossby waves in upper main-sequence stars: r-mode oscillations in many Kepler stars
• On the sensitivity of gravito-inertial modes to differential rotation in intermediate-mass main-sequence stars
• Finding binaries from phase modulation of pulsating stars with Kepler: V. Orbital parameters, with eccentricity and mass-ratio distributions of 341 new binaries
• Detecting non-uniform period spacings in the Kepler photometry of gamma Doradus stars: methodology and case studies
• Gravity modes in rapidly rotating stars. Limits of perturbative methods
• First Kepler results on compact pulsators VIII: Mode identifications via period spacings in $g-$mode pulsating Subdwarf B stars
• Asteroseismic fingerprints of rotation and mixing in the slowly pulsating B8 V star KIC 7760680
• Optimal identification of HII regions during reionization in 21-cm observations
• Deciphering the oscillation spectrum of $\gamma$ Doradus and SPB stars
• KIC 10080943: a binary star with two $\gamma$ Doradus/$\delta$ Scuti hybrid pulsators. Analysis of the g modes
• KIC 10080943: An eccentric binary system containing two pressure- and gravity-mode hybrid pulsators
• An astrophysical interpretation of the remarkable g-mode frequency groups of the rapidly rotating $\gamma$ Dor star, KIC 5608334
• Gravity Modes Reveal the Internal Rotation of a Post-mass Transfer Gamma Doradus/Delta Scuti Hybrid Pulsator in Kepler Eclipsing Binary KIC 9592855
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• Multi-technique investigation of the binary fraction among A-F type candidate hybrid variable stars discovered by Kepler
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• Asteroseismology of the ZZ Ceti star KUV 11370+4222
• Theoretical seismic properties of pre-main sequence gamma Doradus pulsators
• Classifying galaxy spectra at 0.5<z<1 with self-organizing maps

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