find_lines_derivative

specutils.fitting.find_lines_derivative(spectrum, flux_threshold=None)

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:

spectrumSpectrum1D

The spectrum object over which the equivalent width will be calculated.

flux_thresholdfloat, Quantity or 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.

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.