{
  "id": "1711.10919",
  "version": "v1",
  "published": "2017-11-29T15:32:16.000Z",
  "updated": "2017-11-29T15:32:16.000Z",
  "title": "Calibration of the photometric G passband for Gaia Data Release 1",
  "authors": [
    "J. Maíz Apellániz"
  ],
  "comment": "Four-page letter, accepted for publication in A&A",
  "categories": [
    "astro-ph.IM",
    "astro-ph.GA",
    "astro-ph.SR"
  ],
  "abstract": "Context. On September 2016 the first data from Gaia were released (DR1). The first release included photometry for over 10^9 sources in the very broad G system. Aims. To test the correspondence between G magnitudes in DR1 and the synthetic equivalents derived using spectral energy distributions from observed and model spectrophotometry. To correct the G passband curve and to measure the zero point in the Vega system. Methods. I have computed the synthetic G and Tycho-2 BV photometry for a sample of stars using the Next Generation Spectral Library (NGSL) and the Hubble Space Telescope (HST) CALSPEC spectroscopic standards. Results. I have found that the nominal G passband curve is too blue for the DR1 photometry, as shown by the presence of a color term in the comparison between observed and synthetic magnitudes. A correction to the passband applying a power law in lambda with an exponent of 0.783 eliminates the color term. The corrected passband has a Vega zero point of 0.070$\\pm$0.004 magnitudes.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2017-11-29T15:32:16.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "gaia data",
      "calibration",
      "color term",
      "photometric",
      "passband curve"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 0,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}