specex.lines module

SPEX - SPectra EXtractor.

Emission and absorption line dictionary

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class specex.lines.Emission1D(lines_identifications, sigma=3, redshift=0, **kwargs)[source]

Simple model for a flat spectrum with emission lines.

evaluate(lam, redshift)[source]

Evaluate the model.

Parameters

lamnp.ndarray: Array of wavelength.
redshiftfloat, optional: The redshift of the spectrum. The default value is 0.

Returns

resultnp.ndarray: The model values.

param_names = ('redshift',)

Names of the parameters that describe models of this type.

The parameters in this tuple are in the same order they should be passed in when initializing a model of a specific type. Some types of models, such as polynomial models, have a different number of parameters depending on some other property of the model, such as the degree.

When defining a custom model class the value of this attribute is automatically set by the ~astropy.modeling.Parameter attributes defined in the class body.

specex.lines.get_lines(name=None, line_type=None, wrange=None, z=0)[source]

Return line data according to the given line name and types.

Parameters

namestr or None, optional: The name of the line (eg. CaII_H or FeI, etc…). If None, the lines are selected only by type. If both name and type are None, all lines are returned.
line_typestr or None, optional: Type of the line, can be ‘A’ (absorption), ‘E’ (emission) ‘B’ (Broad). If None, then all the line types are returned. The default is None.
wrangetuple/list/np.ndarray of floats or None, optional: The wavelength ragne in which lines should be. If None, no selection according to the line wavelenght is made. The default is None.
zfloat, optional: The redshit of the lines. The default value is 0.

Returns

selected_lineslist: List of line data. Each element of the list is a 3-tuple in the form (wavelenght in Angstrom, Line name, Line type).

Get the redshift of a set of line identifications.

Parameters

identificationsUnion[tuple, list, np.array]: A list of identification generated by get_spectrum_lines().
z_maxOptional[float], optional: The maximum redshift. The default is 6.
z_minOptional[float], optional: The minimum redshift. The default is 0.
z_pointsOptional[Union[float, None]], optional: Number of redshift values between z_min and z_max to test. If None, then z_points = 1000*(z_max - z_min). The default is None.
tolOptional[float], optional: The tolerance. If None, it is computed automatically. The default is None.

Returns

z_values: Best estimations of the redshift sorted from the most probable to the least probable.
z_probs: Pseudo-probabilities of the redshift estimations (the higer the better)

specex.lines.get_spectrum_lines(wavelengths: ndarray, flux: ndarray, var: ndarray | None = None, sigma_threshold: float | None = 10.0, smoothing_window: int | None = 51, smoothing_order: int | None = 1, glob_smoothing: int | None = 3)[source]

Identify the position of clear emission or absorption lines.

Parameters

wavelengthsnp.ndarray: The wavelengs corresponding to each flux value.
fluxnumpy.ndarray: The spectrum itself.
varnumpy.ndarray, optional: The variance of the spectrum itself. The default value is None.
sigma_thresholdfloat, optional: The threshold to use for line identification. The default value is 5.0
smoothing_windowint, optional: Parameter to be passed to the smoothing function. The default value is 51.
smoothing_orderint, optional: Parameter to be passed to the smoothing function. The default value is 11.
glob_smoothingint, optional: Parameter used for line identification. The default value is 3

Returns

identificationslist: A list of tuple. Each tuple ha the form of (k, w, l, h) and contains the index k for the wavelenght w of the line, the approximate max width l of the line and a height h of the line. Note that l and h are not actual phisical quantities and should be used with caution when comparing to other values from a different spectrum.