{
  "id": "2105.08690",
  "version": "v2",
  "published": "2021-05-18T17:21:15.000Z",
  "updated": "2021-08-29T16:10:04.000Z",
  "title": "\"Worst-Case\" Micro-Lensing in the Identification and Modeling of Lensed Quasars",
  "authors": [
    "Luke Weisenbach",
    "Paul Schechter",
    "Sahil Pontula"
  ],
  "comment": "12 pages, 4 figures. As accepted for publication in ApJ",
  "categories": [
    "astro-ph.GA"
  ],
  "abstract": "Although micro-lensing of macro-lensed quasars and supernovae provides unique opportunities for several kinds of investigations, it can add unwanted and sometimes substantial noise. While micro-lensing flux anomalies may be safely ignored for some observations, they severely limit others. \"Worst-case\" estimates can inform the decision whether or not to undertake an extensive examination of micro-lensing scenarios. Here, we report \"worst-case\" micro-lensing uncertainties for point sources lensed by singular isothermal potentials, parameterized by a convergence equal to the shear and by the stellar fraction. The results can be straightforwardly applied to non-isothermal potentials utilizing the mass sheet degeneracy. We use micro-lensing maps to compute fluctuations in image micro-magnifications and estimate the stellar fraction at which the fluctuations are greatest for a given convergence. We find that the worst-case fluctuations happen at a stellar fraction $\\kappa_\\star=\\frac{1}{|\\mu_{macro}|}$. For macro-minima, fluctuations in both magnification and demagnification appear to be bounded ($1.5>\\Delta m>-1.3$, where $\\Delta m$ is magnitude relative to the average macro-magnification). Magnifications for macro-saddles are bounded as well ($\\Delta m > -1.7$). In contrast, demagnifications for macro-saddles appear to have unbounded fluctuations as $1/\\mu_{macro}\\rightarrow0$ and $\\kappa_\\star\\rightarrow0$.",
  "revisions": [
    {
      "version": "v2",
      "updated": "2021-08-29T16:10:04.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "lensed quasars",
      "stellar fraction",
      "identification",
      "singular isothermal potentials",
      "worst-case fluctuations happen"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 12,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}