{
  "id": "1809.09135",
  "version": "v1",
  "published": "2018-09-24T18:03:21.000Z",
  "updated": "2018-09-24T18:03:21.000Z",
  "title": "Coefficients of variation for detecting solar-like oscillations",
  "authors": [
    "Keaton J. Bell",
    "Saskia Hekker",
    "James S. Kuszlewicz"
  ],
  "comment": "11 pages, 6 figures. Accepted for publication in MNRAS",
  "categories": [
    "astro-ph.SR",
    "astro-ph.IM"
  ],
  "abstract": "Detecting the presence and characteristic scale of a signal is a common problem in data analysis. We develop a fast statistical test of the null hypothesis that a Fourier-like power spectrum is consistent with noise. The null hypothesis is rejected where the local \"coefficient of variation\" (CV)---the ratio of the standard deviation to the mean---in a power spectrum deviates significantly from expectations for pure noise (CV~1.0 for a Chi^2 2-degrees-of-freedom distribution). This technique is of particular utility for detecting signals in power spectra with frequency-dependent noise backgrounds, as it is only sensitive to features that are sharp relative to the inspected frequency bin width. We develop a CV-based algorithm to quickly detect the presence of solar-like oscillations in photometric power spectra that are dominated by stellar granulation. This approach circumvents the need for background fitting to measure the frequency of maximum solar-like oscillation power, nu_max. In this paper, we derive the basic method and demonstrate its ability to detect the pulsational power excesses from the well-studied APOKASC-2 sample of oscillating red giants observed by Kepler. We recover the cataloged nu_max values with an average precision of 2.7% for 99.5% of the stars with 4 years of Kepler photometry. Our method produces false positives for <1% of dwarf stars with nu_max well above the long-cadence Nyquist frequency. The algorithm also flags spectra that exhibit astrophysically interesting signals in addition to single, solar-like oscillation power excesses, which we catalog as part of our characterization of the Kepler light curves of APOKASC-2 targets.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2018-09-24T18:03:21.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "detecting solar-like oscillations",
      "coefficient",
      "null hypothesis",
      "method produces false positives",
      "long-cadence nyquist frequency"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 11,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}