find_lines_derivative¶
- specutils.fitting.find_lines_derivative(spectrum, flux_threshold=None)[source]¶
Find the emission and absorption lines in a spectrum. The method here is based on finding the zero crossings in the derivative of the spectrum.
- Parameters:
- spectrum
Spectrum1D The spectrum object over which the equivalent width will be calculated.
- flux_thresholdfloat,
Quantityor None The threshold a pixel must be above to be considered part of a line. If a float, will assume the same units as
spectrum.flux. This threshold is above and beyond the derivative searching step. Default is None so no thresholding. The threshold is positive for emission lines and negative for absorption lines.
- spectrum
- Returns:
- qtable:
QTable Table of emission and absorption lines. Line center (
line_center), line type (line_type) and index of line center (line_center_index) are stored for each line.
- qtable: