{
  "caI": {
    "source": "https://arxiv.org/pdf/1903.08503",
    "paper": "Blouin et al. 2019, Figure 3, black theoretical curve",
    "source_sha256": "357f84ad02982cd29f30d227187f011fe24c53044982b94e9a8e115699bd7103",
    "method": "Extracted vector path 130 from PDF page 3, calibrated against plot bounding box: T=0..6000 K, gamma/nHe=10..28 times 1e-21 cm^-1/(cm^-3). These are digitized figure values, not author tabulated data.",
    "quantity": "Lorentzian core HWHM in wavenumber divided by helium number density",
    "validity": "Core described by Lorentzian up to nHe=1e21 cm^-3. Not valid for far wings, even at that density. No extrapolation above 6000 K.",
    "data": [
      {
        "temperature_K": 665,
        "HWHM_per_nHe_cm2": 1.0752e-20
      },
      {
        "temperature_K": 735,
        "HWHM_per_nHe_cm2": 1.1326e-20
      },
      {
        "temperature_K": 860,
        "HWHM_per_nHe_cm2": 1.2075e-20
      },
      {
        "temperature_K": 2000,
        "HWHM_per_nHe_cm2": 1.6559e-20
      },
      {
        "temperature_K": 3000,
        "HWHM_per_nHe_cm2": 1.9726e-20
      },
      {
        "temperature_K": 4000,
        "HWHM_per_nHe_cm2": 2.1905e-20
      },
      {
        "temperature_K": 5000,
        "HWHM_per_nHe_cm2": 2.4182e-20
      },
      {
        "temperature_K": 6000,
        "HWHM_per_nHe_cm2": 2.5494e-20
      }
    ]
  },
  "naCore": [
    [
      {
        "center": 589.755754,
        "hwhmPerN": 1.58215423e-20
      },
      {
        "center": 589.158263,
        "hwhmPerN": 2.41406325e-20
      }
    ],
    [
      {
        "center": 589.755754,
        "hwhmPerN": 1.80711162e-20
      },
      {
        "center": 589.158263,
        "hwhmPerN": 2.77098585e-20
      }
    ],
    [
      {
        "center": 589.755754,
        "hwhmPerN": 1.9410595000000002e-20
      },
      {
        "center": 589.158263,
        "hwhmPerN": 2.96469806e-20
      }
    ],
    [
      {
        "center": 589.755754,
        "hwhmPerN": 2.10812941e-20
      },
      {
        "center": 589.158263,
        "hwhmPerN": 3.19697341e-20
      }
    ]
  ],
  "li": {
    "source": "https://hal.science/hal-00876511",
    "formula": "Allard et al. 2014 equations 4,5; HWHM cm^-1 = coefficient*nHe*T^exponent",
    "coefficients": [
      6.7307e-22,
      9.4943e-22
    ],
    "exponents": [
      0.40453,
      0.39382
    ],
    "temperature_range_K": [
      500,
      4000
    ]
  },
  "caII": {
    "source": "https://articles.adsabs.harvard.edu/pdf/1975ApJ...196..291H",
    "paper": "G. L. Hammond, The Broadening of Calcium II H and K Lines by Helium, ApJ 196:291-305 (1975)",
    "pages": "301 equations 6-7; 302 equations 8-10; 300 experimental conditions; 303 validity discussion",
    "quantity": "Lorentzian core HWHM in wavenumber, cm^-1, divided by helium number density in cm^-3",
    "reference_temperature_K": 5200,
    "formula": "gamma_wavenumber_cm^-1 = coefficient_cm2 * nHe_cm^-3 * (T_K/5200)^temperature_exponent",
    "K": {
      "wavelength_air_nm": 393.366,
      "coefficient_cm2": 1.71e-20,
      "temperature_exponent": 0.229
    },
    "H": {
      "wavelength_air_nm": 396.847,
      "coefficient_cm2": 1.28e-20,
      "temperature_exponent": 0.228
    },
    "coefficient_relative_uncertainty": 0.3,
    "temperature_exponent_uncertainty": "Not quantified, described as far more uncertain because of poor statistics. Use only within measured range; not a universal temperature law.",
    "measured_temperature_range_K": [
      4400,
      6080
    ],
    "measured_number_density_range_cm^-3": [
      1.6e+21,
      3.1e+21
    ],
    "validity": "Impact/core-width fit. Density-linear continuation below measured density is an impact-theory extrapolation. Does not reproduce unified far-wing asymmetry or satellites. Hammond estimates impact critical density ~5e21 cm^-3, and cautions measurements are close to it. Later Allard & Alekseev 2014 unified profiles supersede the Lorentzian treatment for far wings.",
    "verified": "Equations visually checked in original scanned PDF pages 301 and 302. Note gamma is HALF of full width at half intensity; no extra factor of two in coefficient."
  }
}