Spectral Energy Distribution: templates and more

The SED Object

The spectral energy distribution (SED) template that PISCOLA uses to correct the light curves is represented by the SEDTemplate class and can be called in the following way:

from piscola.sed_class import SEDTemplate

sed = SEDTemplate()
print(sed)

name: conley09f, z: 0.0, ra: None, dec: None

The name refers to the name of the SED template in the templates directory in PISCOLA (conley09f by default). The sed object can also be initiallised with different coordinates (ra and dec) and redshift (z) which are used for correcting the light curves from dust extinction and time dilation. This object contains the information shown below:

sed.__dict__

{'z': 0.0,
 'ra': None,
 'dec': None,
 'data':         phase     wave          flux
 0       -20.0   1000.0  3.533845e-38
 1       -20.0   1010.0  3.533845e-38
 2       -20.0   1020.0  3.533845e-38
 3       -20.0   1030.0  3.533845e-38
 4       -20.0   1040.0  3.533845e-38
 ...       ...      ...           ...
 243160   85.0  23890.0  5.169887e-12
 243161   85.0  23900.0  5.223790e-12
 243162   85.0  23910.0  5.278787e-12
 243163   85.0  23920.0  5.334638e-12
 243164   85.0  23930.0  5.391089e-12

 [243165 rows x 3 columns],
 'phase': array([-20., -20., -20., ...,  85.,  85.,  85.]),
 'wave': array([ 1000.,  1010.,  1020., ..., 23910., 23920., 23930.]),
 'flux': array([3.5338449e-38, 3.5338449e-38, 3.5338449e-38, ..., 5.2787867e-12,
        5.3346382e-12, 5.3910892e-12]),
 'flux_err': array([0., 0., 0., ..., 0., 0., 0.]),
 'name': 'conley09f',
 'comments': '',
 'redshifted': False,
 'extincted': False}

where data is a pandas DataFrame. If a README.txt file is found in the templates directory, it is added to the comments.

The available SED templates can be shown in the following way:

sed.show_available_templates()

List of available SED templates: ['conley09f', 'guy07', 'jla']

For information about the available functions, check the SED Class.

Adding New SED Templates

SEDs are stored under the templates directory, in their own respective directories. PISCOLA reads the file sed_template.dat to import a template, where the first column of the file are the phases in units of days (e.g. epochs with respect to \(B\)-band peak magnitude), the second one are the wavelengths in angstroms, and the last one are the fluxes in any arbitrary units (as a function of wavelength). If you want to add another template, just follow the same structure.