{
  "id": "1505.02531",
  "version": "v1",
  "published": "2015-05-11T09:02:51.000Z",
  "updated": "2015-05-11T09:02:51.000Z",
  "title": "On a new theoretical framework for RR Lyrae stars I: the metallicity dependence",
  "authors": [
    "M. Marconi",
    "G. Coppola",
    "G. Bono",
    "V. Braga",
    "A. Pietrinferni",
    "R. Buonanno",
    "M. Castellani",
    "I. Musella",
    "V. Ripepi",
    "R. F. Stellingwerf"
  ],
  "comment": "73 pages, 20 figures, 9 tables, accepted for publication on ApJ",
  "categories": [
    "astro-ph.SR"
  ],
  "abstract": "We present new nonlinear, time-dependent convective hydrodynamical models of RR Lyrae stars computed assuming a constant helium-to-metal enrichment ratio and a broad range in metal abundances (Z=0.0001--0.02). The stellar masses and luminosities adopted to construct the pulsation models were fixed according to detailed central He burning Horizontal Branch evolutionary models. The pulsation models cover a broad range in stellar luminosity and effective temperatures and the modal stability is investigated for both fundamental and first overtones. We predict the topology of the instability strip as a function of the metal content and new analytical relations for the edges of the instability strip in the observational plane. Moreover, a new analytical relation to constrain the pulsation mass of double pulsators as a function of the period ratio and the metal content is provided. We derive new Period-Radius-Metallicity relations for fundamental and first-overtone pulsators. They agree quite well with similar empirical and theoretical relations in the literature. From the predicted bolometric light curves, transformed into optical (UBVRI) and near-infrared (JHK) bands, we compute the intensity-averaged mean magnitudes along the entire pulsation cycle and, in turn, new and homogenous metal-dependent (RIJHK) Period-Luminosity relations. Moreover, we compute new dual and triple band optical, optical--NIR and NIR Period-Wesenheit-Metallicity relations. Interestingly, we find that the optical Period-W(V,B-V) is independent of the metal content and that the accuracy of individual distances is a balance between the adopted diagnostics and the precision of photometric and spectroscopic datasets.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2015-05-11T09:02:51.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "rr lyrae stars",
      "metallicity dependence",
      "theoretical framework",
      "metal content",
      "constant helium-to-metal enrichment ratio"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 73,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}