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remove_telluric_division

Remove telluric absorption by dividing the science spectrum by a reference.
Category Corrections
Backend numpy - implemented here on top of numpy primitives
Version 1.1.0
Reads ctx.spectrum (a Spectrum1D)
Writes spectrum

Provide the telluric template either via template_path (a FITS file) or by storing a Spectrum1D in ctx.extras['telluric_spectrum']. Since v1.1.0, when template_key is left at its default 'telluric_spectrum' and that key is absent, the brick falls back to ctx.extras['telluric_template_scaled'] (written by fit_telluric_scaling) and then ctx.extras['telluric_template'] (written by synth_telluric), so the chain synth_telluric → fit_telluric_scaling → remove_telluric_division works with all defaults. The key actually used is recorded in meta['telluric_template_key']. The template's wavelength axis may be in any order (sorted internally).

Parameters

Parameter Default Required Description
template_path None - Path / URL to the telluric standard FITS spectrum.
template_key 'telluric_spectrum' - Key into ctx.extras holding a Spectrum1D template. With the default 'telluric_spectrum' absent, 'telluric_template_scaled' then 'telluric_template' are tried.
min_transmission 0.05 - Below this normalised value the spectrum is masked, not divided.

Use it

from spectro_kernel import run_algorithm

output = run_algorithm("remove_telluric_division", ctx, {
    "template_path": None,
    "template_key": "telluric_spectrum",
    "min_transmission": 0.05
})

spectro run remove_telluric_division --input spectrum.fits \
  --param template_path=none \
  --param template_key=telluric_spectrum \
  --param min_transmission=0.05

{
  "tool": "remove_telluric_division",
  "arguments": {
    "session_id": "<session_id>",
    "params": {
      "template_path": null,
      "template_key": "telluric_spectrum",
      "min_transmission": 0.05
    }
  }
}

Every algorithm is an MCP tool of the same name; describe_algorithm returns this page's metadata as JSON.

References

  • Vacca, Cushing & Rayner 2003, PASP 115, 389 — telluric correction methodology