API Documentation

lightcurve_fitting.bolometric module

lightcurve_fitting.bolometric.blackbody_lstsq(epoch1, z, p0=None, T_range=(1.0, 100.0), R_range=(0.01, 1000.0), cutoff_freq=inf)[source]

Fit a blackbody spectrum to a spectral energy distribution using \(χ^2\) minimization

Parameters:
epoch1lightcurve_fitting.lightcurve.LC

A single “epoch” of photometry that defines the observed spectral energy distribution

zfloat

Redshift between the blackbody (rest frame) and the filters (observed frame)

p0list, tuple, array-like, optional

Initial guess for [temperature (kK), radius (1000 Rsun)]. Default: [10., 10.]

T_rangetuple, list, array-like, optional

Range of allowed temperatures (in kilokelvins) in the prior. Default: (1., 100.)

R_rangetuple, list, array-like, optional

Range of allowed radii (in 1000 solar radii) in the prior. Default: (0.01, 1000.)

cutoff_freqfloat, optional

Cutoff frequency (in terahertz) for a modified blackbody spectrum (see https://doi.org/10.3847/1538-4357/aa9334)

Returns:
tempfloat

Best-fit blackbody temperature in kilokelvins

radiusfloat

Best-fit blackbody radius in units of 1000 solar radii

dtempfloat

Uncertainty in the temperature in kilokelvins

dradfloat

Uncertainty in the radius in units of 1000 solar radii

lumfloat

Blackbody luminosity implied by the best-fit temperature and radius

dlumfloat

Uncertainty in the blackbody luminosity

L_optfloat

Pseudobolometric luminosity from integrating the best-fit blackbody spectrum over the U-I filters

lightcurve_fitting.bolometric.calc_colors(epoch1, colors)[source]

Calculate colors from a spectral energy distribution

Parameters:
epoch1lightcurve_fitting.lightcurve.LC

A single “epoch” of photometry that defines the observed spectral energy distribution

colorslist

A list of colors to calculate, e.g., ['U-B', 'B-V', 'g-r', 'r-i']

Returns:
magslist

A list of the calculated colors

dmagslist

A list of uncertainties on the calculated colors, from propagating errors on the photometry points

lolimslist

A list of booleans: True if the first filter is a nondetection or is absent from epoch1

uplimslist

A list of booleans: True if the second filter is a nondetection or is absent from epoch1

lightcurve_fitting.bolometric.calculate_bolometric(lc, z=0.0, outpath='.', res=1.0, nwalkers=10, burnin_steps=200, steps=100, priors=None, save_table_as=None, min_nfilt=3, cutoff_freq=inf, show=False, colors=None, do_mcmc=True, save_chains=False, use_sigma=False, sigma_type='relative', also_group_by=())[source]

Calculate the full bolometric light curve from a table of broadband photometry.

To manually specify epochs for some or all points, add a unique number in the ‘epoch’ column of the lc.

Parameters:
lclightcurve_fitting.lightcurve.LC

Table of broadband photometry including columns “MJD”, “mag”, “dmag”, “filter”

zfloat, optional

DEPRECATED: Include the redshift in lc.meta[‘redshift’] instead.

outpathstr, optional

Directory to which to save the corner plots and MCMC chains. Default: current directory

resfloat, optional

Approximate resolution for grouping, in days. Default: 1 day.

nwalkersint, optional

Number of walkers (chains) to use for fitting. Default: 10

burnin_stepsint, optional

Number of MCMC steps before convergence. This part of the history is discarded. Default: 200

stepsint, optional

Number of MCMC steps after convergence. This part of the history is used to calculate paramers. Default: 100.

priorslist, optional

Prior probability distributions for temperature (in kilokelvins) and radius (in 1000 solar radii). Available priors: models.UniformPrior, models.LogUniformPrior, models.GaussianPrior. Default: T = Uniform(1., 100.), R = LogUniform(0.01, 1000.), σ = Gaussian(0., 10., stddev=1.).

save_table_asstr, optional

Filename to which to save the output table of blackbody parameters and bolometric luminosities

min_nfiltint, optional

Minimum number of distinct observed filters required to calculate a luminosity. Default: 3

cutoff_freqfloat, optional

Cutoff frequency (in terahertz) for a modified blackbody spectrum (see https://doi.org/10.3847/1538-4357/aa9334)

showbool, optional

Plot the chain histories, and display all plots at the end of the script. Default: only save the corner plot

colorslist, optional

A list of colors to calculate, e.g., ['U-B', 'B-V', 'g-r', 'r-i']

do_mcmcbool, optional

If True (default), also fit the spectral energy distribution with an MCMC routine. This is slower but gives more realistic uncertainties.

save_chainsbool, optional

If True, save the MCMC chain histories to the directory outpath. Default: only save the corner plot

use_sigmabool, optional

Include an intrinsic scatter parameter in the MCMC fit. Default: False.

sigma_typestr, optional

If ‘relative’ (default), sigma will be in units of the individual photometric uncertainties. If ‘absolute’, sigma will be in units of the median photometric uncertainty.

also_group_bylist, optional

Group by these columns in addition to epoch

Returns:
t0lightcurve_fitting.lightcurve.LC

Table containing the blackbody parameters, bolometric luminosities, and (optionally) colors

lightcurve_fitting.bolometric.group_by_epoch(lc, res=1.0, also_group_by=())[source]

Group a light curve into epochs that will be treated as single spectral energy distributions.

To manually specify epochs for some or all points, add a unique number in the ‘epoch’ column of the lc.

Parameters:
lclightcurve_fitting.lightcurve.LC

Table containing the observed photometry. Must contain times in an “MJD” column.

resfloat, optional

Approximate resolution for grouping, in days. Default: 1 day.

also_group_bylist, tuple, optional

Column names to group by, in addition to epoch. Default: ().

Returns:
groupslist of lightcurve_fitting.lightcurve.LC

Iterable containing single-epoch spectral energy distributions, sorted by average MJD

lightcurve_fitting.bolometric.integrate_sed(epoch1)[source]

Directly integrate a spectral energy distribution using the trapezoidal rule

Parameters:
epoch1lightcurve_fitting.lightcurve.LC

A single “epoch” of photometry that defines the observed spectral energy distribution

Returns:
L_intfloat

Luminosity in watts

lightcurve_fitting.bolometric.median_and_unc(x, perc_contained=68.0)[source]

Calculate the equal-tailed credible interval, centered on the median, for a sample of data

Parameters:
xarray-like

The data sample

perc_containedfloat, optional

The percentage of the probability to be contained in the interval. Default: 68% (1σ)

Returns:
medianfloat

The median of x

lowerfloat

The lower boundary of the credible interval

upperfloat

The upper boundary of the credible interval

lightcurve_fitting.bolometric.plot_bolometric_results(t0, save_plot_as=None, xcol=None, log=False)[source]

Plot the parameters and bolometric light curves that result from fitting the spectral energy distribution

Parameters:
t0lightcurve_fitting.lightcurve.LC

Table containing the results from fitting the spectral energy distribution

save_plot_asstr, optional

Filename to which to save the plot.

xcolstr, optional

Column to plot on the x-axis. Default: 'phase' if t0.meta['refmjd'] and t0.meta['redshift'] are given, otherwise 'MJD'. (See the docs for LC.calcPhase().)

logbool, optional

Use a logarithmic x-axis. Only useful if xcol='phase'. Default: False.

Returns:
figmatplotlib.pyplot.Figure

Figure object containing the plot

lightcurve_fitting.bolometric.plot_chain(chain, labels=None)[source]

Plot the chain histories for an MCMC run

Parameters:
chainarray-like

Array containing the MCMC chain history, e.g., from emcee.EnsembleSampler.chain()

labelsiterable, optional

A list of axis labels for each parameter in the chain

Returns:
figmatplotlib.pyplot.Figure

Figure object containing the chain history plots

lightcurve_fitting.bolometric.plot_color_curves(t, colors=None, fmt='o', limit_length=0.1, xcol='MJD')[source]

Plot the color curves calculated by calculate_bolometric().

Parameters:
tlightcurve_fitting.lightcurve.LC

Output table from calculate_bolometric()

colorslist, optional

List of colors to plot, e.g., ['g-r', 'r-i']. By default, plot all recognizable colors.

fmtstr, optional

Format string, passed to matplotlib.pyplot.errorbar()

limit_lengthfloat, optional

Length (in data units) of the upper and lower limit markers

Returns:
figmatplotlib.pyplot.Figure

Figure object containing the plot

lightcurve_fitting.bolometric.pseudo(temp, radius, z, filter0=<filter I>, filter1=<filter U>, cutoff_freq=inf)[source]

Integrate a blackbody spectrum between two broadband filters to produce a pseudobolometric luminosity

Parameters:
tempfloat, array-like

Blackbody temperatures in kilokelvins

radiusfloat, array-like

Blackbody radii in units of 1000 solar radii

zfloat

Redshift between the blackbody (rest frame) and the filters (observed frame)

filter0, filter1lightcurve_fitting.filters.Filter, optional

Filters to integrate between, where filter1 is bluer than filter0. Default: U to I.

cutoff_freqfloat, optional

Cutoff frequency (in terahertz) for a modified blackbody spectrum (see https://doi.org/10.3847/1538-4357/aa9334)

Returns:
L_optfloat, array-like

Pseudobolometric luminosity in watts

lightcurve_fitting.bolometric.spectrum_corner(spectrum, epoch1, sampler_flatchain, z=0.0, ebv=0.0, spectrum_kwargs=None, use_sigma=False, labels=None, freq_min=100.0, freq_max=1000.0, save_plot_as='')[source]

Plot the posterior distributions in a corner (pair) plot, with an inset showing the observed and model SEDs.

Parameters:
spectrumfunction

Function describing the spectrum. The first argument must be frequency in THz, and it must return spectral luminosity in watts per hertz. For a blackbody, you can use models.planck_fast().

epoch1lightcurve_fitting.lightcurve.LC

A single “epoch” of photometry that defines the observed spectral energy distribution

sampler_flatchainarray-like

2D array containing the aggregated MCMC chain histories

zfloat, optional

Redshift between the emission source and the observed filter. Default: 0.

ebvfloat, array-like, optional

Selective extinction \(E(B-V)\) in magnitudes, evaluated using a Fitzpatrick (1999) extinction law with \(R_V=3.1\). Its shape must be broadcastable to any array-like arguments. Default: 0.

spectrum_kwargsdict, optional

Keyword arguments to be passed to the spectrum function.

use_sigmabool, optional

Include an intrinsic scatter parameter. Default: False.

labelslist, optional

Axis labels for the chain histories and corner plot.

freq_min, freq_maxfloat, optional

Minimum and maximum frequencies for the SED panel in the corner plot. Default: (100., 1000.) or observed range.

save_plot_asstr, optional

Filename to which to save the resulting plot

Returns:
f4matplotlib.pyplot.Figure

Figure containing the corner and SED plots.

lightcurve_fitting.bolometric.spectrum_mcmc(spectrum, epoch1, priors, starting_guesses, z=0.0, ebv=0.0, spectrum_kwargs=None, show=False, outpath='.', nwalkers=10, burnin_steps=200, steps=100, save_chains=False, use_sigma=False, sigma_type='relative', labels=None, freq_min=100.0, freq_max=1000.0)[source]

Fit the given spectral energy distribution to an epoch of photometry using a Markov-chain Monte Carlo routine

Parameters:
spectrumfunction

Function describing the spectrum. The first argument must be frequency in THz, and it must return spectral luminosity in watts per hertz. For a blackbody, you can use models.planck_fast().

epoch1lightcurve_fitting.lightcurve.LC

A single “epoch” of photometry that defines the observed spectral energy distribution

priorslist

Prior probability distributions for each model parameter (and sigma, if used). Available priors: models.UniformPrior (default), models.LogUniformPrior, models.GaussianPrior

starting_guessesarray-like

Initial guesses for each input parameter to spectrum. Must have shape (nwalkers, nparameters).

zfloat, optional

Redshift between the emission source and the observed filter. Default: 0.

ebvfloat, array-like, optional

Selective extinction \(E(B-V)\) in magnitudes, evaluated using a Fitzpatrick (1999) extinction law with \(R_V=3.1\). Its shape must be broadcastable to any array-like arguments. Default: 0.

spectrum_kwargsdict, optional

Keyword arguments to be passed to the spectrum function.

showbool, optional

Plot the chain histories, and display all plots at the end of the script. Default: only save the corner plot

outpathstr, optional

Directory to which to save the corner plots. Default: current directory

nwalkersint, optional

Number of walkers (chains) to use for fitting. Default: 10

burnin_stepsint, optional

Number of MCMC steps before convergence. This part of the history is discarded. Default: 200

stepsint, optional

Number of MCMC steps after convergence. This part of the history is used to calculate parameters. Default: 100.

save_chainsbool, optional

If True, save the MCMC chain histories to the directory outpath. Default: only save the corner plot

use_sigmabool, optional

Include an intrinsic scatter parameter. Default: False.

sigma_typestr, optional

If ‘relative’ (default), sigma will be in units of the individual photometric uncertainties. If ‘absolute’, sigma will be in units of the median photometric uncertainty.

labelslist, optional

Axis labels for the chain histories and corner plot.

freq_min, freq_maxfloat, optional

Minimum and maximum frequencies for the SED panel in the corner plot. Default: (100., 1000.) or observed range.

Returns:
sampleremcee.EnsembleSampler

Sampler object containing the results of the MCMC fit

lightcurve_fitting.bolometric.stefan_boltzmann(temp, radius, dtemp=None, drad=None, covTR=None)[source]

Calculate blackbody luminosity and associated uncertainty using the Stefan-Boltzmann law

Parameters:
tempfloat, array-like

Temperature in kilokelvins.

radiusfloat, array-like

Radius in units of 1000 solar radii.

dtempfloat, array-like, optional

Uncertainty in the temperature in kilokelvins

dradfloat, array-like, optional

Uncertainty in the radius in units of 1000 solar radii

covTRfloat, array-like, optional

Covariance between the temperature and radius

Returns:
lumfloat, array-like

Luminosity in watts

dlumfloat, array-like

Uncertainty in the luminosity in watts (returned only if dtemp, drad, and covTR are given)

lightcurve_fitting.filters module

class lightcurve_fitting.filters.Filter(names, color='k', offset=0, system=None, fnu=3.631e-23, filename='', angstrom=False, linecolor=None, textcolor=None, mec=None, italics=True)[source]

Bases: object

A broadband photometric filter described by its transmission function and its associated photometric system

Parameters:
namesstr, list

One or more names for the filter. The first name is used by default but other names are recognized.

colorstr, tuple, optional

The color used when plotting photometry in this filter. Default: black.

offsetfloat, optional

When plotting, offset photometry in this filter by this amount (in magnitudes if plotting magnitudes)

systemstr, optional

Photometric system. Only used for grouping filters in legends.

fnufloat, optional

Zero-point flux for magnitudes in this filter, in W/(m^2 Hz). If fnu = None and system in ['Gunn', 'ATLAS', 'Gaia', 'MOSFiT'], assume the AB zero point. Otherwise if fnu = None, converting to flux will raise an error.

filenamestr, optional

Filename containing the transmission function. If none is supplied, converting to flux will raise an error.

angstrombool, optional

If False (default), the transmission function wavelengths are assumed to be in nanometers. If True, they are given in ångströms.

linecolorstr, tuple, optional

The line color used when plotting photometry in this filter. Default: same as color.

textcolorstr, tuple, optional

The color used when printing the name of this filter. Default: same as linecolor.

mecstr, tuple, optional

The marker edge color used when plotting photometry in this filter. Default: same as linecolor.

italicsbool, optional

Italicize the filter name when used with LaTeX. Default: True.

Attributes:
namestr

The default name of the filter

nameslist

A list of aliases for the filter

charstr

A single-character identifier for the filter

colorstr, tuple

The color used when plotting photometry in this filter

linecolorstr, tuple

The line and marker edge color used when plotting photometry in this filter

textcolorstr, tuple

The color used when printing the name of this filter

italicsbool

Italicize the filter name when used with LaTeX

mecstr, tuple

The marker edge color used when plotting photometry in this filter

plotstyledict

Contains all keyword arguments for plotting photometry in this filter

offsetfloat

When plotting, offset photometry in this filter by this amount (in magnitudes if plotting magnitudes)

systemstr

The photometric system for magnitudes in this filter

fnufloat

The zero-point flux for magnitudes in this filter, in watts per square meter per hertz

m0float

The zero point for magnitudes in this filter, i.e., \(m_0 = 2.5 \log_{10}(F_ν)\)

M0float

The zero point for absolute magnitudes in this filter, i.e., \(M_0 = m_0 + 90.19\)

filenamestr

Filename containing the transmission function

angstrombool

If False (default), the transmission function wavelengths are assumed to be in nanometers. If True, they are given in ångströms.

transastropy.table.Table

The transmission function

freq_efffloat

The effective frequency of the filter (in terahertz), i.e., \(ν_0 = \frac{1}{Δν} \int ν T(ν) dν\)

dfreqfloat

The effective bandwidth of the filter (in terahertz), i.e., \(Δν = \int T(ν) dν\)

freq_rangetuple

The approximate edges of the filter transmission function (in terahertz), i.e., \(ν_0 \pm Δν\)

property dfreq
property dwl
extinction(ebv, rv=3.1, z=0.0)[source]

Extinction \(A_\lambda\) at the effective wavelength of this filter

Parameters:
ebvarray-like

Selective extinction \(E(B-V)\) in magnitudes

rvfloat, optional

Ratio of total to selective extinction \(R_V\). Default: 3.1.

zfloat, optional

Redshift between the dust and the observed filter. Default: 0 (appropriate for Milky Way extinction).

Returns:
extinctionfloat

Extinction at the effective wavelength of this filter in magnitudes

property freq_eff
property freq_range
order = ['FUV', 'NUV', 'UVW2', 'UVM2', 'UVW1', 'u', 'U_S', 'U', 'B', 'B_S', 'g', 'g-DECam', 'c', 'V', 'V_S', 'Itagaki', 'white', 'unfilt.', 'G', 'Kepler', 'TESS', 'DLT40', 'w', 'o', 'r', 'r-DECam', 'R', 'i', 'i-DECam', 'I', 'z_s', 'z', 'z-DECam', 'y', 'y-DECam', 'J', 'H', 'K', 'L', 'F070W', 'F090W', 'F115W', 'F150W', 'F182M', 'F200W', 'F250M', 'F277W', 'F300M', 'F335M', 'F356W', 'F360M', 'F444W', 'F560W', 'F770W', 'F1000W', 'F1130W', 'F1280W', 'F1500W', 'F1800W', 'F2100W', 'F2550W', 'pseudobolometric, curve_fit', 'pseudobolometric, MCMC', 'pseudobolometric, integration', 'bolometric, curve_fit', 'bolometric, MCMC', 'unknown']

The names of recognized filters listed in (approximate) decreasing order of effective frequency

read_curve(show=False, force=False)[source]

Read the transmission function from self.filename and store it in self.trans

Parameters:
showbool, optional

If True, also plot the transmission function

forcebool, optional

If True, reread the transmission function from self.filename even if is already stored in self.trans

spectrum(freq, lum, z=0.0, ebv=0.0)[source]

Return the average value of the given spectrum in this filter

The limits of integration come from the input spectrum, so if the spectrum does not cover the full filter, this function returns the average Lnu within the overlapping region, i.e., it does not extrapolate.

Parameters:
freqfloat or array-like

Frequency of the input spectrum in THz

lumfloat or array-like

Spectral luminosity (Lnu) or flux (Fnu) of the input spectrum

zfloat, optional

Redshift between the spectrum and the filter. Default: 0.

ebvfloat, array-like, optional

Selective extinction \(E(B-V)\) in magnitudes, evaluated using a Fitzpatrick (1999) extinction law with \(R_V=3.1\). Default: 0.

Returns:
Lnufloat or array-like

Average spectral luminosity (Lnu) or flux (Fnu) in the filter

synthesize(spectrum, *args, z=0.0, ebv=0.0, **kwargs)[source]

Returns the average Lnu of the given spectrum in this filter

Parameters:
spectrumfunction

Function describing the spectrum. The first argument must be frequency in THz, and it must return spectral luminosity in watts per hertz. All arguments are passed to this function except for keywords z and ebv.

zfloat, optional

Redshift between the emission source and the observed filter. Default: 0.

ebvfloat, array-like, optional

Selective extinction \(E(B-V)\) in magnitudes, evaluated using a Fitzpatrick (1999) extinction law with \(R_V=3.1\). Its shape must be broadcastable to any array-like arguments. Default: 0.

Returns:
Lnufloat or array-like

Average spectral luminosity in the filter in watts per hertz

property trans
property wl_eff
property wl_range
lightcurve_fitting.filters.extinction_law(freq, ebv, rv=3.1)[source]

A vectorized version of the Fitzpatrick (1999) extinction law from the extinction package

Parameters:
freqarray-like

Frequencies in THz in the frame of the dust

ebvarray-like

Selective extinction \(E(B-V)\) in magnitudes

rvfloat, optional

Ratio of total to selective extinction \(R_V\). Default: 3.1.

Returns:
extinctionarray-like

Extinction factor \(10^{A/-2.5}\) at each input wavelength.

lightcurve_fitting.fitting module

lightcurve_fitting.fitting.format_credible_interval(x, sigfigs=1, percentiles=(15.87, 50.0, 84.14), axis=0, varnames=None, units=None)[source]

Use LaTeX to format an equal-tailed credible interval with a given number of significant figures in the uncertainty

Parameters:
xarray-like

Data from which to calculate the credible interval

sigfigsint, optional

Number of significant figures in the uncertainty. Default: 1

percentilestuple, optional

Percentiles for the (lower, center, upper) of the credible interval. Default: (15.87, 50., 84.14) (median +/- 1σ)

axisint, optional

Axis of x along which to calculate the credible intervals. Default: 0

varnameslist, optional

Variable names to be equated with the credible intervals. Default: no variable names

unitslist, optional

Units to be applied to the credible intervals. Default: no units

Returns:
paramtextsstr

The formatted credible intervals

lightcurve_fitting.fitting.lightcurve_corner(lc, model, sampler_flatchain, model_kwargs=None, num_models_to_plot=100, lcaxis_posn=(0.7, 0.55, 0.2, 0.4), filter_spacing=1.0, tmin=None, tmax=None, t0_offset=None, save_plot_as='', ycol=None, textsize='medium', param_textsize='large', use_sigma=False, xscale='linear', filters_to_model=None, label_filters=True, lc_plot_kwargs=None, model_plot_kwargs=None)[source]

Plot the posterior distributions in a corner (pair) plot, with an inset showing the observed and model light curves.

Parameters:
lclightcurve_fitting.lightcurve.LC

Table of broadband photometry including columns “MJD”, “mag”, “dmag”, “filter”

modellightcurve_fitting.models.Model

The model that was fit to the light curve.

sampler_flatchainarray-like

2D array containing the aggregated MCMC chain histories

model_kwargsdict, optional

DEPRECATED: Keyword arguments are now included in the model initialization

num_models_to_plotint, optional

Number of model realizations to plot in the light curve inset. Default: 100

lcaxis_posntuple, optional

Light curve inset position and size specification in figure units: (left, bottom, width, height)

filter_spacingfloat, optional

Spacing between filters in the light curve inset, in units determined by the order of magnitude of the luminosities. Default: 1.

tmin, tmaxfloat, optional

Starting and ending times for which to plot the models in the light curve inset. Default: determined by the time range of the observed light curve.

t0_offsetfloat, optional
Reference time for the explosion time in the corner plot and the horizontal axis of the light curve inset.

Default: the earliest explosion time in sampler_flatchain, rounded down.

save_plot_asstr, optional

Filename to which to save the resulting plot

ycolstr, optional

Quantity to plot on the light curve inset. Choices: “lum”, “flux”, or “absmag”. Default: model.output_quantity

textsizestr, optional

Font size for the x- and y-axis labels, as well as the tick labels. Default: ‘medium’

param_textsizestr, optional

Font size for the parameter text. Default: ‘large’

use_sigmabool, optional

If True, treat the last parameter as an intrinsic scatter parameter that does not get passed to the model

xscalestr, optional

Scale for the x-axis of the model plot. Choices: “linear” (default) or “log”.

filters_to_modellist, set, optional

(Unique) list of filters for which to calculate the model light curves. Default: all filters in lc.

label_filtersbool, optional

Print the name and offset for each filter to the right of the light curve axis. Default: True

lc_plot_kwargsdict, optional

Dictionary of keyword arguments for the plotting of the observed light curve (passed to the lc.plot command)

model_plot_kwargsdict, optional

Dictionary of keyword arguments for the plotting of the model light curves (passed to the plt.plot command)

Returns:
figmatplotlib.pyplot.Figure

Figure object containing the plot

corner_axarray-like

Array of matplotlib.pyplot.Axes objects corresponding to the corner plot

axmatplotlib.pyplot.Axes

Axes object for the light curve inset

lightcurve_fitting.fitting.lightcurve_mcmc(lc, model, priors=None, p_min=None, p_max=None, p_lo=None, p_up=None, nwalkers=100, nsteps=1000, nsteps_burnin=1000, model_kwargs=None, show=False, save_plot_as='', save_sampler_as='', use_sigma=False, sigma_type='relative')[source]

Fit an analytical model to observed photometry using a Markov-chain Monte Carlo routine

Parameters:
lclightcurve_fitting.lightcurve.LC

Table of broadband photometry including columns “MJD”, “mag”, “dmag”, “filter”

modellightcurve_fitting.models.Model

The model to fit to the light curve. Available models: models.ShockCooling, models.ShockCooling2, models.ShockCooling3, models.CompanionShocking, models.CompanionShocking2, models.CompanionShocking3

priorslist, optional

Prior probability distributions for each model parameter. Available priors: models.UniformPrior (default), models.LogUniformPrior, models.GaussianPrior

p_min, p_maxlist, optional

DEPRECATED: Use priors instead

p_lolist

Lower bounds on the starting guesses for each paramter

p_uplist

Upper bounds on the starting guesses for each parameter

nwalkersint, optional

Number of walkers (chains) for the MCMC routine. Default: 100

nstepsint, optional

Number of steps (iterations) for the MCMC routine, excluding burn-in. Default: 1000

nsteps_burninint, optional

Number of steps (iterations) for the MCMC routine during burn-in. Default: 1000

model_kwargsdict, optional

DEPRECATED: Keyword arguments are now included in the model initialization

showbool, optional

If True, plot and display the chain histories

save_plot_asstr, optional

Save a plot of the chain histories to this filename

save_sampler_asstr, optional

Save the aggregated chain histories to this filename

use_sigmabool, optional

If True, treat the last parameter as an intrinsic scatter parameter that does not get passed to the model

sigma_typestr, optional

If ‘relative’ (default), sigma will be in units of the individual photometric uncertainties. If ‘absolute’, sigma will be in units of the median photometric uncertainty.

Returns:
sampleremcee.EnsembleSampler

EnsembleSampler object containing the results of the fit

lightcurve_fitting.fitting.lightcurve_model_plot(lc, model, sampler_flatchain, model_kwargs=None, num_models_to_plot=100, filter_spacing=1.0, tmin=None, tmax=None, ycol=None, textsize='medium', ax=None, mjd_offset=None, use_sigma=False, xscale='linear', filters_to_model=None, label_filters=True, lc_plot_kwargs=None, model_plot_kwargs=None)[source]

Plot the observed and model light curves.

Parameters:
lclightcurve_fitting.lightcurve.LC

Table of broadband photometry including columns “MJD”, “mag”, “dmag”, “filter”

modellightcurve_fitting.models.Model

The model that was fit to the light curve.

sampler_flatchainarray-like

2D array containing the aggregated MCMC chain histories

model_kwargsdict, optional

DEPRECATED: Keyword arguments are now included in the model initialization.

num_models_to_plotint, optional

Number of model realizations to plot in the light curve inset. Default: 100

filter_spacingfloat, optional

Spacing between filters in the light curve inset, in units determined by the order of magnitude of the luminosities. Default: 1.

tmin, tmaxfloat, optional

Starting and ending times for which to plot the models in the light curve inset. Default: determined by the time range of the observed light curve.

ycolstr, optional

Quantity to plot on the light curve inset. Choices: “lum”, “flux”, or “absmag”. Default: model.output_quantity

textsizestr, optional

Font size for the x- and y-axis labels, as well as the tick labels. Default: ‘medium’

axmatplotlib.pyplot.Axes

Axis on which to plot the light curves

mjd_offsetfloat, optional

Reference time on the horizontal axis of the light curve inset. Default: determined by the starting time of the model light curve.

use_sigmabool, optional

If True, treat the last parameter as an intrinsic scatter parameter that does not get passed to the model

xscalestr, optional

Scale for the x-axis. Choices: “linear” (default) or “log”.

filters_to_modellist, set, optional

(Unique) list of filters for which to calculate the model light curves. Default: all filters in lc.

label_filtersbool, optional

Print the name and offset for each filter to the right of the light curve axis. Default: True

lc_plot_kwargsdict, optional

Dictionary of keyword arguments for the plotting of the observed light curve (passed to the lc.plot command)

model_plot_kwargsdict, optional

Dictionary of keyword arguments for the plotting of the model light curves (passed to the plt.plot command)

lightcurve_fitting.lightcurve module

class lightcurve_fitting.lightcurve.Arrow(hx, hy)[source]

Bases: Path

An downward-pointing arrow-shaped Path, whose head has half-width hx and height hy (in units of length)

class lightcurve_fitting.lightcurve.LC(*args, **kwargs)[source]

Bases: Table

A broadband light curve, stored as an astropy.table.Table

Attributes:
nondetSigmasfloat

Significance level implied by nondetections in the light curve. Default: 3σ

groupbyset

Column names to group by when binning the light curve. Default: {'filter', 'source'}

markersdict

Mapping of some light curve property (default: 'source' or 'telescope') to marker shapes

bin(delta=0.3, groupby=None)[source]

Bin the light curve by averaging points within delta days of each other

Parameters:
deltafloat, optional

Bin size, in days. Default: 0.3 days

groupbyset, optional

Column names to group by before binning. Default: {'filter', 'source'}

Returns:
lclightcurve_fitting.lightcurve.LC

Binned light curve

calcAbsMag(dm=None, extinction=None, hostext=None, ebv=None, rv=None, host_ebv=None, host_rv=None, redshift=None)[source]

Calculate the 'absmag' column from the 'mag' column by correcting for distance and extinction

Parameters:
dmfloat, optional

Distance modulus. Default: calculate from redshift.

extinctiondict, optional

Milky Way extinction coefficients \(A_λ\) for each filter. Default: calculate from ebv and rv.

hostextdict, optional

Host galaxy extinction coefficients \(A_λ\) for each filter. Default: calculate from host_ebv and host_rv.

ebvfloat, optional

Milky Way selective extinction \(E(B-V)\), used if extinction is not given. Default: 0.

host_ebvfloat, optional

Host galaxy selective extinction \(E(B-V)\), used if hostext is not given. Default: 0.

rvfloat, optional

Ratio of total to selective Milky Way extinction \(R_V\), used with the ebv argument. Default: 3.1.

host_rvfloat, optional

Ratio of total to selective host-galaxy extinction \(R_V\), used with the host_ebv argument. Default: 3.1.

redshiftfloat, optional

Redshift of the host galaxy. Used to redshift the filters for host galaxy extinction. If no distance modulus is given, a redshift-dependent distance is calculated using the Planck18 cosmology. Default: 0.

calcFlux(nondetSigmas=None, zp=None)[source]

Calculate the 'flux' and 'dflux' columns from the 'mag' and 'dmag' columns

Parameters:
nondetSigmasfloat, optional

Significance level implied by nondetections in the light curve. Default: 3σ

zpfloat, array-like, optional

Array of zero points for each magnitude. Default: standard for each filter

calcLum(nondetSigmas=None)[source]

Calculate the 'lum' and 'dlum' columns from the 'absmag' and 'dmag' columns

Parameters:
nondetSigmasfloat, optional

Significance level implied by nondetections in the light curve. Default: 3σ

calcMag(nondetSigmas=None, zp=None)[source]

Calculate the 'mag' and 'dmag' columns from the 'flux' and 'dflux' columns

Parameters:
nondetSigmasfloat, optional

Significance level implied by nondetections in the light curve. Default: 3σ

zpfloat, array-like, optional

Array of zero points for each magnitude. Default: standard for each filter

calcPhase(rdsp=False, hours=False)[source]

Calculate the rest-frame 'phase' column from 'MJD', .meta['refmjd'], and .meta['redshift']

Parameters:
rdspbool, optional

Define phase as rest-frame days since peak, rather than rest-frame days since explosion

hoursbool, optional

Give the phase in rest-frame hours instead of rest-frame days

filters_to_objects()[source]

Parse the 'filter' column into filters.Filter objects

findNondet(nondetSigmas=None)[source]

Add a boolean column 'nondet' indicating flux measurements that are below the detection threshold

Parameters:
nondetSigmasfloat, optional

Significance level implied by nondetections in the light curve. Default: 3σ

findPeak(**criteria)[source]

Find the peak of the light curve and store it in .meta['peakdate']

Parameters:
criteriadict, optional

Use only a subset of the light curve matching some criteria when calculating the peak date (stored in .meta['peakcriteria'])

get(key, default=masked)[source]
normalize_column_names()[source]

Rename any recognizable columns to their standard names for this package (see lightcurve.column_names).

plot(xcol='phase', ycol='absmag', offset_factor=1.0, color='filter', marker=None, use_lines=False, normalize=False, fillmark=True, mjd_axis=True, appmag_axis=True, loc_mark=None, loc_filt=None, ncol_mark=1, lgd_filters=None, tight_layout=True, phase_hours=False, return_axes=False, frameon=True, **kwargs)[source]

Plot the light curve, with nondetections marked with a downward-pointing arrow

Parameters:
xcolstr, optional

Column to plot on the horizontal axis. Default: 'phase'

ycolstr, optional

Column to plot on the vertical axis. Default: 'absmag'

offset_factorfloat, optional

Increase or decrease the filter offsets by a constant factor. Default: 1.

colorstr, optional

Column that controls the color of the lines and points. Default: 'filter'

markerstr, optional

Column that controls the marker shape. Default: 'source' or 'telescope'

use_linesbool, optional

Connect light curve points with lines. Default: False

normalizebool, optional

Normalize all light curves to peak at 0. Default: False

fillmarkbool, optional

Fill each marker with color. Default: True

mjd_axisbool, optional

Plot MJD on the upper x-axis. Must have .meta['redshift'] and .meta['refmjd']. Default: True.

appmag_axisbool, optional

Plot extinction-corrected apparent magnitude on the right y-axis. Must have .meta['dm']. Default: True.

loc_mark, loc_filtstr, optional

Location for the marker and filter legends, respectively. Set to ‘none’ to omit them. Three new options are available: ‘above’, ‘above left’, and ‘above right’. mjd_axis and/or appmag_axis must be used to add these legends. Otherwise run plt.legend() after plotting for a single simple legend. Default: no legend.

ncol_markint, optional

Number of columns in the marker legend. Default: 1.

lgd_filterslist, array-like, optional

Customize the arrangement of filters in the legend by providing a list of filters for each column. None can be used to leave a blank space in the column. Only filters given here will be used. The default arrangement shows all filters arranged by .system (columns) and .offset (rows).

tight_layoutbool, optional

Adjust the figure margins to look beautiful. Default: True.

phase_hoursbool, optional

Plot the phase in units of rest-frame hours instead of rest-frame days. Default: False.

return_axesbool, optional

Return the newly created axes if mjd_axis=True or appmag_axis=True. Default: False.

kwargs

Keyword arguments matching column names in the light curve are used to specify a subset of points to plot. Additional keyword arguments passed to matplotlib.pyplot.plot().

Returns:
topmatplotlib.pyplot.Axes, optional

The upper x-axis, if mjd_axis=True and return_axes=True. Otherwise, None.

rightmatplotlib.pyplot.Axes, optional

The right y-axis, if appmag_axis=True and return_axes=True. Otherwise, None.

classmethod read(filepath, format='ascii', fill_values=None, **kwargs)[source]

Read and parse a data table and return as a Table.

This function provides the Table interface to the astropy unified I/O layer. This allows easily reading a file in many supported data formats using syntax such as:

>>> from astropy.table import Table
>>> dat = Table.read('table.dat', format='ascii')
>>> events = Table.read('events.fits', format='fits')

Get help on the available readers for Table using the``help()`` method:

>>> Table.read.help()  # Get help reading Table and list supported formats
>>> Table.read.help('fits')  # Get detailed help on Table FITS reader
>>> Table.read.list_formats()  # Print list of available formats

See also: https://docs.astropy.org/en/stable/io/unified.html

Parameters:
*argstuple, optional

Positional arguments passed through to data reader. If supplied the first argument is typically the input filename.

formatstr

File format specifier.

unitslist, dict, optional

List or dict of units to apply to columns

descriptionslist, dict, optional

List or dict of descriptions to apply to columns

**kwargsdict, optional

Keyword arguments passed through to data reader.

Returns:
out~astropy.table.Table

Table corresponding to file contents

Notes

The available built-in formats are:

Format

Read

Write

Auto-identify

Deprecated

ascii

Yes

Yes

No

ascii.aastex

Yes

Yes

No

ascii.basic

Yes

Yes

No

ascii.cds

Yes

No

No

ascii.commented_header

Yes

Yes

No

ascii.csv

Yes

Yes

Yes

ascii.daophot

Yes

No

No

ascii.ecsv

Yes

Yes

Yes

ascii.fast_basic

Yes

Yes

No

ascii.fast_commented_header

Yes

Yes

No

ascii.fast_csv

Yes

Yes

No

ascii.fast_no_header

Yes

Yes

No

ascii.fast_rdb

Yes

Yes

No

ascii.fast_tab

Yes

Yes

No

ascii.fixed_width

Yes

Yes

No

ascii.fixed_width_no_header

Yes

Yes

No

ascii.fixed_width_two_line

Yes

Yes

No

ascii.html

Yes

Yes

Yes

ascii.ipac

Yes

Yes

No

ascii.latex

Yes

Yes

Yes

ascii.mrt

Yes

Yes

No

ascii.no_header

Yes

Yes

No

ascii.qdp

Yes

Yes

Yes

ascii.rdb

Yes

Yes

Yes

ascii.rst

Yes

Yes

No

ascii.sextractor

Yes

No

No

ascii.tab

Yes

Yes

No

fits

Yes

Yes

Yes

hdf5

Yes

Yes

Yes

pandas.csv

Yes

Yes

No

pandas.fwf

Yes

No

No

pandas.html

Yes

Yes

No

pandas.json

Yes

Yes

No

parquet

Yes

Yes

Yes

votable

Yes

Yes

Yes

aastex

Yes

Yes

No

Yes

cds

Yes

No

No

Yes

csv

Yes

Yes

No

Yes

daophot

Yes

No

No

Yes

html

Yes

Yes

No

Yes

ipac

Yes

Yes

No

Yes

latex

Yes

Yes

No

Yes

mrt

Yes

Yes

No

Yes

rdb

Yes

Yes

No

Yes

Deprecated format names like aastex will be removed in a future version. Use the full name (e.g. ascii.aastex) instead.

where(**kwargs)[source]

Select the subset of a light curve matching some criteria, given as keyword arguments, e.g., colname=value.

The keyword colname can be any of the following:

  • a column in the table, in which case rows must match value in that column

  • a column in the table + _not, in which case rows must not match value in that column

  • a column in the table + _min, in which case rows must be >= value in that column

  • a column in the table + _max, in which case rows must be <= value in that column

value must match the data type of the column colname and can either be a single value or a list of values. If value is a list, rows must match at least one of the values. If value is a list and colname ends in _not, rows must not match any of the values.

write(*args, **kwargs)[source]

Write this Table object out in the specified format.

This function provides the Table interface to the astropy unified I/O layer. This allows easily writing a file in many supported data formats using syntax such as:

>>> from astropy.table import Table
>>> dat = Table([[1, 2], [3, 4]], names=('a', 'b'))
>>> dat.write('table.dat', format='ascii')

Get help on the available writers for Table using the``help()`` method:

>>> Table.write.help()  # Get help writing Table and list supported formats
>>> Table.write.help('fits')  # Get detailed help on Table FITS writer
>>> Table.write.list_formats()  # Print list of available formats

The serialize_method argument is explained in the section on Table serialization methods.

See also: https://docs.astropy.org/en/stable/io/unified.html

Parameters:
*argstuple, optional

Positional arguments passed through to data writer. If supplied the first argument is the output filename.

formatstr

File format specifier.

serialize_methodstr, dict, optional

Serialization method specifier for columns.

**kwargsdict, optional

Keyword arguments passed through to data writer.

Notes

The available built-in formats are:

Format

Read

Write

Auto-identify

Deprecated

ascii

Yes

Yes

No

ascii.aastex

Yes

Yes

No

ascii.basic

Yes

Yes

No

ascii.commented_header

Yes

Yes

No

ascii.csv

Yes

Yes

Yes

ascii.ecsv

Yes

Yes

Yes

ascii.fast_basic

Yes

Yes

No

ascii.fast_commented_header

Yes

Yes

No

ascii.fast_csv

Yes

Yes

No

ascii.fast_no_header

Yes

Yes

No

ascii.fast_rdb

Yes

Yes

No

ascii.fast_tab

Yes

Yes

No

ascii.fixed_width

Yes

Yes

No

ascii.fixed_width_no_header

Yes

Yes

No

ascii.fixed_width_two_line

Yes

Yes

No

ascii.html

Yes

Yes

Yes

ascii.ipac

Yes

Yes

No

ascii.latex

Yes

Yes

Yes

ascii.mrt

Yes

Yes

No

ascii.no_header

Yes

Yes

No

ascii.qdp

Yes

Yes

Yes

ascii.rdb

Yes

Yes

Yes

ascii.rst

Yes

Yes

No

ascii.tab

Yes

Yes

No

fits

Yes

Yes

Yes

hdf5

Yes

Yes

Yes

jsviewer

No

Yes

No

pandas.csv

Yes

Yes

No

pandas.html

Yes

Yes

No

pandas.json

Yes

Yes

No

parquet

Yes

Yes

Yes

votable

Yes

Yes

Yes

votable.parquet

No

Yes

No

aastex

Yes

Yes

No

Yes

csv

Yes

Yes

No

Yes

html

Yes

Yes

No

Yes

ipac

Yes

Yes

No

Yes

latex

Yes

Yes

No

Yes

mrt

Yes

Yes

No

Yes

rdb

Yes

Yes

No

Yes

Deprecated format names like aastex will be removed in a future version. Use the full name (e.g. ascii.aastex) instead.

property zp

Returns an array of zero points for each filter in the 'filter' column

lightcurve_fitting.lightcurve.aux_axes(xfunc=None, yfunc=None, ax0=None, xfunc_args=None, yfunc_args=None)[source]

Add auxiliary axes to a plot that are linear transformations of the existing axes

Parameters:
xfuncfunction, optional

Function that transforms the lower x-axis to the upper x-axis. Default: do not add an upper x-axis.

yfuncfunction, optional

Function that transforms the left y-axis to the right y-axis. Default: do not add a right y-axis.

ax0matplotlib.pyplot.Axes, optional

Existing axes object. Default: use the current Axes.

xfunc_args, yfunc_argsdict, optional

Keyword arguments for xfunc and yfunc, respectively

Returns:
topmatplotlib.pyplot.Axes

The upper x-axis, if any. Otherwise, None.

rightmatplotlib.pyplot.Axes

The right y-axis, if any. Otherwise, None.

lightcurve_fitting.lightcurve.binflux(time, flux, dflux, delta=0.2, include_zero=True)[source]

Bin a light curve by averaging points within delta of each other in time

Parameters:
time, flux, dfluxarray-like

Arrays of times, fluxes, and uncertainties comprising the observed light curve

deltafloat, optional

Bin size, in the same units as time. Default: 0.2

include_zerobool, optional

Include data points with no error bar

Returns:
time, flux, dfluxarray-like

Binned arrays of times, fluxes, and uncertainties

lightcurve_fitting.lightcurve.custom_legend(ax, handles, labels, top_axis=True, **kwargs)[source]

Add a legend to the axes with options for loc='above', loc='above left', and loc='above right'

Parameters:
axmatplotlib.pyplot.Axes, matplotlib.pyplot.Figure

Axes or Figure object to which to add the legend

handleslist of matplotlib.pyplot.Artist

A list of Artists (lines, patches) to be added to the legend

labelslist of str

A list of labels to show next to the handles

top_axisbool, optional

For legends above the top of the plot, add extra padding to the upper x-axis labels. Default: True.

kwargs

Keyword arguments to be passed to matplotlib.pyplot.legend()

Returns:
lgdmatplotlib.legend.Legend

The Legend object

lightcurve_fitting.lightcurve.filter_legend(filts, offset_factor=1.0)[source]

Creates dummy artists and labels for the filter legend using the filter properties

Parameters:
filtsset, list, array-like

If a list or array of strings, the arrangement of filters in the legend, with columns in the first dimension and rows in the second. If a set of Filter objects, they will first be arranged using filtsetup().

offset_factorfloat, optional

Increase or decrease the filter offsets by a constant factor. Default: 1.

Returns:
lineslist of matplotlib.pyplot.Artist

A list of Artists (lines, patches) to be added to the legend

labelslist of str

A list of labels to show next to the handles

ncolint

Number of columns needed for the filter legend

lightcurve_fitting.lightcurve.filtsetup(filts)[source]

Arrange filters in a grid according to their system (columns) and offset (rows)

Parameters:
filtsset

A set of Filter objects to be arranged

Returns:
lgndnumpy.array

A 2D array of Filter objects

lightcurve_fitting.lightcurve.flux2mag(flux, dflux=array(nan), zp=0.0, nondet=None, nondetSigmas=3.0)[source]

Convert flux (and uncertainty) to magnitude (and uncertainty). Nondetections are converted to limiting magnitudes.

Parameters:
fluxfloat, array-like

Flux to be converted

dfluxfloat, array-like, optional

Uncertainty on the flux to be converted. Default: numpy.nan

zpfloat, array-like, optional

Zero point to be applied to the magnitudes

nondetarray-like

Boolean or index array indicating the nondetections among the fluxes. Default: no nondetections

nondetSigmasfloat, optional

Significance level implied by nondetections in the light curve. Default: 3σ

Returns:
magfloat, array-like

Magnitude corresponding to the input flux

dmagfloat, array-like

Uncertainty on the output magnitude

lightcurve_fitting.lightcurve.mag2flux(mag, dmag=nan, zp=0.0, nondet=None, nondetSigmas=3.0)[source]

Convert magnitude (and uncertainty) to flux (and uncertainty). Nondetections are assumed to imply zero flux.

Parameters:
magfloat, array-like

Magnitude to be converted

dmagfloat, array-like, optional

Uncertainty on the magnitude to be converted. Default: numpy.nan

zpfloat, array-like, optional

Zero point to be applied to the magnitudes

nondetarray-like

Boolean or index array indicating the nondetections among the fluxes. Default: no nondetections

nondetSigmasfloat, optional

Significance level implied by nondetections in the light curve. Default: 3σ

Returns:
fluxfloat, array-like

Flux corresponding to the input magnitude

dfluxfloat, array-like

Uncertainty on the output flux

lightcurve_fitting.models module

class lightcurve_fitting.models.BaseCompanionShocking(lc, redshift=0.0)[source]

Bases: Model

The companion shocking model of Kasen (https://doi.org/10.1088/0004-637X/708/2/1025) plus the SiFTO SN Ia model.

As written by Hosseinzadeh et al. (https://doi.org/10.3847/2041-8213/aa8402), the shock component is defined by:

\(R_\mathrm{phot}(t) = (2700\,R_\odot) (M_c v_9^7)^{1/9} κ^{1/9} t^{7/9}\) (Eq. 1)

\(T_\mathrm{eff}(t) = (25\,\mathrm{kK}) a_{13}^{1/4} (M_c v_9^7)^{1/144} κ^{-35/144} t^{37/72}\) (Eq. 2)

The SiFTO model (https://doi.org/10.1086/588518) is currently only available in the UBVgri filters.

Parameters:
lclightcurve_fitting.lightcurve.LC, optional

The light curve to which the model will be fit. Only used for lc.meta[‘redshift’] if z is not given.

redshiftfloat, optional

The redshift between blackbody source and the observed filters. Default: 0.

Attributes:
zfloat

The redshift between blackbody source and the observed filters

siftoastropy.table.Table

A copy of the SiFTO model scaled to match the observed peak luminosity in each filter

companion_shocking(t_in, f, t_exp, a13, Mc_v9_7, kappa=1.0)[source]

Evaluate the shock component only at a range of times and filters

Parameters:
t_infloat, array-like

Time in days

flightcurve_fitting.filter.Filter, array-like

Filters for which to calculate the model

t_expfloat, array-like

The explosion epoch

a13float, array-like

The binary separation in \(10^{13}\) cm

Mc_v9_7float, array-like

The product \(M_c v_9^7\), where \(M_c\) is the ejecta mass in Chandrasekhar masses and \(v_9\) is the ejecta velocity in units of \(10^9\) cm/s

kappafloat, array-like

The ejecta opacity in units of the electron scattering opacity (0.34 cm^2/g)

Returns:
y_fitarray-like

The filtered model light curves

abstract evaluate(*args, **kwargs)[source]
stretched_sifto(t_in, f, t_peak, stretch, dtU=None, dti=None)[source]

The SiFTO SN Ia model (https://doi.org/10.1086/588518), offset and stretched by the input parameters

The SiFTO model is currently only available in the UBVgri filters. We assume unfiltered photometry can be modeled as r.

Parameters:
t_infloat, array-like

Time in days

flightcurve_fitting.filter.Filter, array-like

Filters for which to calculate the model

t_peakfloat, array-like

The epoch of maximum light for the SiFTO model

stretchfloat, array-like

The stretch for the SiFTO model

dtU, dtifloat, array-like

Time offsets for the U- and i-band models relative to the other bands

Returns:
y_fitarray-like

The filtered model light curves

static t_max(p)[source]

The maximum time at which the model is valid

This is the last epoch at which the stretched SiFTO model is computed

static t_min(p)[source]

The minimum time at which the model is valid

This is the first epoch at which the stretched SiFTO model is computed

static temperature_radius(t_in, t_exp, a13, Mc_v9_7, kappa=1.0)[source]

Evaluate the color temperature and photospheric radius of the shock component as a function of time

Parameters:
t_infloat, array-like

Time in days

t_expfloat, array-like

The explosion epoch

a13float, array-like

The binary separation in \(10^{13}\) cm

Mc_v9_7float, array-like

The product \(M_c v_9^7\), where \(M_c\) is the ejecta mass in Chandrasekhar masses and \(v_9\) is the ejecta velocity in units of \(10^9\) cm/s

kappafloat, array-like

The ejecta opacity in units of the electron scattering opacity (0.34 cm^2/g)

Returns:
T_kasenarray-like

The model blackbody temperatures in units of kilokelvins

R_kasenarray-like

The model blackbody radii in units of 1000 solar radii

class lightcurve_fitting.models.BaseShockCooling(lc=None, redshift=0.0, n=1.5, RW=False)[source]

Bases: Model

The shock cooling model of Sapir & Waxman (https://doi.org/10.3847/1538-4357/aa64df).

\(T(t) = \frac{T_\mathrm{col}}{T_\mathrm{ph}} T_0 \left(\frac{v_s^2 t^2}{f_ρ M κ}\right)^{ε_1} \frac{R^{1/4}}{κ^{1/4}} t^{-1/2}\) (Eq. 23)

\(L(t) = A \exp\left[-\left(\frac{a t}{t_\mathrm{tr}}\right)^α\right] L_0 \left(\frac{v_s t^2}{f_ρ M κ}\right)^{-ε_2} \frac{v_s^2 R}{κ}\) (Eq. 18-19)

\(t_\mathrm{tr} = (19.5\,\mathrm{d}) \left(\frac{κ * M_\mathrm{env}}{v_s} \right)^{1/2}\) (Eq. 20)

Parameters:
lclightcurve_fitting.lightcurve.LC, optional

The light curve to which the model will be fit. Only used to get the redshift if redshift is not given.

redshiftfloat, optional

The redshift between blackbody source and the observed filters. Default: 0.

nfloat, optional

The polytropic index of the progenitor. Must be either 1.5 (default) or 3.

RWbool, optional

Reduce the model to the simpler form of Rabinak & Waxman (https://doi.org/10.1088/0004-637X/728/1/63). Default: False.

Attributes:
zfloat

The redshift between blackbody source and the observed filters

nfloat

The polytropic index of the progenitor

Afloat

Coefficient on the luminosity suppression factor (Eq. 19)

afloat

Coefficient on the transparency timescale (Eq. 19)

alphafloat

Exponent on the transparency timescale (Eq. 19)

epsilon_1float

Exponent in the temperature expression (Eq. 23)

epsilon_2float

Exponent in the luminosity expression (Eq. 18)

L_0float

Coefficient on the luminosity expression in erg/s (Eq. 18)

T_0float

Coefficient on the temperature expression in eV (Eq. 23)

Tph_to_Tcolfloat

Ratio of the color temperature to the photospheric temperature

epsilon_Tfloat

Exponent on time in the temperature expression

epsilon_Lfloat

Exponent on time in the luminosity expression

RWbool

Reduce the model to the simpler form of Rabinak & Waxman (https://doi.org/10.1088/0004-637X/728/1/63)

abstract evaluate(*args, **kwargs)[source]
static t_max(p, kappa=1.0)[source]

The maximum time at which the model is valid

\(t_\mathrm{max} = (7.4\,\mathrm{d}) \left(\frac{R}{κ}\right)^{0.55} + t_\mathrm{exp}\) (Eq. 24)

static t_min(p, kappa=1.0)[source]

The minimum time at which the model is valid

\(t_\mathrm{min} = (0.2\,\mathrm{d}) \frac{R}{v_s} \max\left[0.5, \frac{R^{0.4}}{(f_ρ M κ)^{0.2} v_s^{-0.7}}\right] + t_\mathrm{exp}\) (Eq. 17)

temperature_radius(t_in, v_s, M_env, f_rho_M, R, t_exp=0.0, kappa=1.0)[source]

Evaluate the color temperature and photospheric radius as a function of time for a set of parameters

Parameters:
t_infloat, array-like

Time in days

v_sfloat, array-like

The shock speed in \(10^{8.5}\) cm/s

M_envfloat, array-like

The envelope mass in solar masses

f_rho_Mfloat, array-like

The product \(f_ρ M\), where \(f_ρ\) is a numerical factor of order unity that depends on the inner envelope structure and \(M\) is the ejecta mass in solar masses

Rfloat, array-like

The progenitor radius in \(10^{13}\) cm

t_expfloat, array-like

The explosion epoch

kappafloat, array-like

The ejecta opacity in units of the electron scattering opacity (0.34 cm^2/g)

Returns:
T_Karray-like

The model blackbody temperatures in units of kilokelvins

R_bbarray-like

The model blackbody radii in units of 1000 solar radii

class lightcurve_fitting.models.CompanionShocking(lc, redshift=0.0)[source]

Bases: BaseCompanionShocking

The companion shocking model of Kasen (https://doi.org/10.1088/0004-637X/708/2/1025) plus the SiFTO SN Ia model.

This version of the model includes factors on the r and i SiFTO models, and a factor on the U shock component.

evaluate(t_in, f, t_exp, a13, Mc_v9_7, t_peak, stretch, rr=1.0, ri=1.0, rU=1.0, kappa=1.0)[source]

Evaluate this model at a range of times and filters

Parameters:
t_infloat, array-like

Time in days

flightcurve_fitting.filter.Filter, array-like

Filters for which to calculate the model

t_expfloat, array-like

The explosion epoch

a13float, array-like

The binary separation in \(10^{13}\) cm

Mc_v9_7float, array-like

The product \(M_c v_9^7\), where \(M_c\) is the ejecta mass in Chandrasekhar masses and \(v_9\) is the ejecta velocity in units of \(10^9\) cm/s

t_peakfloat, array-like

The epoch of maximum light for the SiFTO model

stretchfloat, array-like

The stretch for the SiFTO model

rrfloat, array-like

A scale factor for the r-band SiFTO model

rifloat, array-like

A scale factor for the i-band SiFTO model

rUfloat, aray-like

A scale factor for the U-band of the shock component

kappafloat, array-like

The ejecta opacity in units of the electron scattering opacity (0.34 cm^2/g)

Returns:
y_fitarray-like

The filtered model light curves

input_names = ['t_0', 'a', 'M v^7', 't_\\mathrm{max}', 's', 'r_r', 'r_i', 'r_U']

A list of the parameter names

units = [Unit("d"), <Quantity 1.e+13 cm>, <Quantity 1.e+63 cm7 M_chandra / s7>, Unit("d"), Unit(dimensionless), Unit(dimensionless), Unit(dimensionless), Unit(dimensionless)]

A list of the units for each parameter

class lightcurve_fitting.models.CompanionShocking2(lc, redshift=0.0)[source]

Bases: BaseCompanionShocking

The companion shocking model of Kasen (https://doi.org/10.1088/0004-637X/708/2/1025) plus the SiFTO SN Ia model.

This version of the model includes time offsets for the U and i SiFTO models.

evaluate(t_in, f, t_exp, a13, Mc_v9_7, t_peak, stretch, dtU=0.0, dti=0.0, kappa=1.0)[source]

Evaluate this model at a range of times and filters

Parameters:
t_infloat, array-like

Time in days

flightcurve_fitting.filter.Filter, array-like

Filters for which to calculate the model

t_expfloat, array-like

The explosion epoch

a13float, array-like

The binary separation in \(10^{13}\) cm

Mc_v9_7float, array-like

The product \(M_c v_9^7\), where \(M_c\) is the ejecta mass in Chandrasekhar masses and \(v_9\) is the ejecta velocity in units of \(10^9\) cm/s

t_peakfloat, array-like

The epoch of maximum light for the SiFTO model

stretchfloat, array-like

The stretch for the SiFTO model

dtU, dtifloat, array-like

Time offsets for the U- and i-band SiFTO models relative to the other bands

kappafloat, array-like

The ejecta opacity in units of the electron scattering opacity (0.34 cm^2/g)

Returns:
y_fitarray-like

The filtered model light curves

input_names = ['t_0', 'a', 'M v^7', 't_\\mathrm{max}', 's', '\\Delta t_U', '\\Delta t_i']

A list of the parameter names

units = [Unit("d"), <Quantity 1.e+13 cm>, <Quantity 1.e+63 cm7 M_chandra / s7>, Unit("d"), Unit(dimensionless), Unit("d"), Unit("d")]

A list of the units for each parameter

class lightcurve_fitting.models.CompanionShocking3(lc, redshift=0.0)[source]

Bases: BaseCompanionShocking

The companion shocking model of Kasen (https://doi.org/10.1088/0004-637X/708/2/1025) plus the SiFTO SN Ia model.

This version of the model includes time offsets for the U and i SiFTO models, as well as the viewing angle dependence parametrized by Brown et al. (https://doi.org/10.1088/0004-637X/749/1/18).

evaluate(t_in, f, t_exp, a13, theta, t_peak, stretch, dtU, dti, kappa=1.0)[source]

Evaluate this model at a range of times and filters

Parameters:
t_infloat, array-like

Time in days

flightcurve_fitting.filter.Filter, array-like

Filters for which to calculate the model

t_expfloat, array-like

The explosion epoch

a13float, array-like

The binary separation in \(10^{13}\) cm

thetafloat, array-like

The angle between the binary axis and the line to the observer in degrees. 0° means the binary companion is along the line of sight.

t_peakfloat, array-like

The epoch of maximum light for the SiFTO model

stretchfloat, array-like

The stretch for the SiFTO model

dtU, dtifloat, array-like

Time offsets for the U- and i-band SiFTO models relative to the other bands

kappafloat, array-like

The ejecta opacity in units of the electron scattering opacity (0.34 cm^2/g)

Returns:
y_fitarray-like

The filtered model light curves

input_names = ['t_0', 'a', '\\theta', 't_\\mathrm{max}', 's', '\\Delta t_U', '\\Delta t_i']

A list of the parameter names

units = [Unit("d"), <Quantity 1.e+13 cm>, Unit("deg"), Unit("d"), Unit(dimensionless), Unit("d"), Unit("d")]

A list of the units for each parameter

class lightcurve_fitting.models.GaussianPrior(p_min=-inf, p_max=inf, mean=0.0, stddev=1.0)[source]

Bases: Prior

A Gaussian prior centered at mean with standard deviation stddev, i.e., \(\frac{dP}{dp} \propto \exp \left( \frac{(p - \mu)^2}{2 \sigma^2} \right)\)

logp(p)[source]
class lightcurve_fitting.models.LogUniformPrior(p_min=0.0, p_max=inf)[source]

Bases: Prior

A uniform prior in the logarithm of the parameter, i.e., \(\frac{dP}{dp} \propto \frac{1}{p}\)

logp(p)[source]
class lightcurve_fitting.models.Model(lc=None, redshift=0.0)[source]

Bases: object

An analytical model, defined by a function and its parameters

property axis_labels

Axis labels for each paramter (including name and unit)

abstract evaluate(*args, **kwargs)[source]
input_names = []

A list of the parameter names

log_likelihood(lc, p, use_sigma=False, sigma_type='relative')[source]

The log of the likelihood function of the model given data contained in lc and parameters contained in p

Parameters:
lclightcurve_fitting.lightcurve.LC

Table of broadband photometry including columns “MJD”, “mag”, “dmag”, “filter”

parray-like

Model parameters for which to calculate the likelihood. The first dimension should have the same length as the number of parameters, or one more if sigma is used.

use_sigmabool, optional

If True, treat the last parameter as an intrinsic scatter parameter that does not get passed to the model

sigma_typestr, optional

If ‘relative’ (default), sigma will be in units of the individual photometric uncertainties. If ‘absolute’, sigma will be in units of the median photometric uncertainty.

Returns:
log_likelihoodfloat, array-like

The natural log of the likelihood function. If p is 1D, log_likelihood is a float. Otherwise, its shape is determined by the remaining dimensions of p.

property nparams

The number of parameters in the model

output_quantity = 'lum'

Quantity output by the model: ‘lum’ or ‘flux’

units = []

A list of the units for each parameter

class lightcurve_fitting.models.Prior(p_min=-inf, p_max=inf)[source]

Bases: object

abstract logp(p)[source]
class lightcurve_fitting.models.ShockCooling(lc=None, redshift=0.0, n=1.5, RW=False)[source]

Bases: BaseShockCooling

The shock cooling model of Sapir & Waxman (https://doi.org/10.3847/1538-4357/aa64df).

This version of the model is written in terms of physical parameters \(v_s, M_\mathrm{env}, f_ρ M, R\).

evaluate(t_in, f, v_s, M_env, f_rho_M, R, t_exp=0.0, kappa=1.0)[source]

Evaluate this model at a range of times and filters

Parameters:
t_infloat, array-like

Time in days

flightcurve_fitting.filter.Filter, array-like

Filters for which to calculate the model

v_sfloat, array-like

The shock speed in \(10^{8.5}\) cm/s

M_envfloat, array-like

The envelope mass in solar masses

f_rho_Mfloat, array-like

The product \(f_ρ M\), where “\(f_ρ\) is a numerical factor of order unity that depends on the inner envelope structure” and \(M\) is the ejecta mass in solar masses

Rfloat, array-like

The progenitor radius in \(10^{13}\) cm

t_expfloat, array-like, optional

The explosion epoch. Default: 0.

kappafloat, array-like, optional

The ejecta opacity in units of the electron scattering opacity (0.34 cm^2/g). Default: 1.

Returns:
y_fitarray-like

The filtered model light curves

input_names = ['v_\\mathrm{s*}', 'M_\\mathrm{env}', 'f_\\rho M', 'R', 't_0']

A list of the parameter names

units = [<Quantity 3.16227766e+08 cm / s>, Unit("solMass"), Unit("solMass"), <Quantity 1.e+13 cm>, Unit("d")]

A list of the units for each parameter

class lightcurve_fitting.models.ShockCooling2(lc=None, redshift=0.0, n=1.5, RW=False)[source]

Bases: BaseShockCooling

The shock cooling model of Sapir & Waxman (https://doi.org/10.3847/1538-4357/aa64df).

This version of the model is written in terms of scaling parameters \(T_1, L_1, t_\mathrm{tr}\):

\(T(t) = T_1 t^{ε_T}\) and \(L(t) = L_1 t^{ε_L} \exp\left[-\left(\frac{a t}{t_\mathrm{tr}}\right)^α\right]\)

evaluate(t_in, f, T_1, L_1, t_tr, t_exp=0.0)[source]

Evaluate this model at a range of times and filters

Parameters:
t_infloat, array-like

Time in days

flightcurve_fitting.filter.Filter, array-like

Filters for which to calculate the model

T_1float, array-like

The blackbody temperature 1 day after explosion in kilokelvins

L_1float, array-like

The approximate blackbody luminosity 1 day after explosion in \(10^{42}\) erg/s

t_trfloat, array-like

The time at which the envelope becomes transparent in rest-frame days

t_expfloat, array-like

The explosion epoch

Returns:
y_fitarray-like

The filtered model light curves

input_names = ['T_1', 'L_1', 't_\\mathrm{tr}', 't_0']

A list of the parameter names

t_max(p, kappa=1.0)[source]

The maximum time at which the model is valid

\(t_\mathrm{max} = \left(\frac{8.12\,\mathrm{kK}}{T_1}\right)^{1/(2 ε_1 - 0.5)} + t_\mathrm{exp}\)

static t_min(p, kappa=1.0)[source]

The minimum time at which the model is valid

This expression cannot be translated to the parameters of ShockCooling2

units = [Unit("kK"), <Quantity 1.e+42 erg / s>, Unit("d"), Unit("d")]

A list of the units for each parameter

class lightcurve_fitting.models.ShockCooling3(lc=None, redshift=0.0, n=1.5, RW=False)[source]

Bases: BaseShockCooling

The shock cooling model of Sapir & Waxman (https://doi.org/10.3847/1538-4357/aa64df).

This version of the model is written in terms of physical parameters \(v_s, M_\mathrm{env}, f_ρ M, R\) and includes distance \(d_L\) and reddening \(E(B-V)\) as free parameters.

evaluate(t_in, f, v_s, M_env, f_rho_M, R, dist, ebv=0.0, t_exp=0.0, kappa=1.0)[source]

Evaluate this model at a range of times and filters

Parameters:
t_infloat, array-like

Time in days

flightcurve_fitting.filter.Filter, array-like

Filters for which to calculate the model

v_sfloat, array-like

The shock speed in \(10^{8.5}\) cm/s

M_envfloat, array-like

The envelope mass in solar masses

f_rho_Mfloat, array-like

The product \(f_ρ M\), where “\(f_ρ\) is a numerical factor of order unity that depends on the inner envelope structure” and \(M\) is the ejecta mass in solar masses

Rfloat, array-like

The progenitor radius in \(10^{13}\) cm

distfloat, array-like

The luminosity distance in Mpc

ebvfloat, array-like, optional

The reddening \(E(B-V)\) to apply to the blackbody spectrum before integration. Default: 0.

t_expfloat, array-like, optional

The explosion epoch. Default: 0.

kappafloat, array-like, optional

The ejecta opacity in units of the electron scattering opacity (0.34 cm^2/g). Default: 1.

Returns:
y_fitarray-like

The filtered model light curves

input_names = ['v_\\mathrm{s*}', 'M_\\mathrm{env}', 'f_\\rho M', 'R', 'd_L', 'E(B-V)', 't_0']

A list of the parameter names

output_quantity = 'flux'

Quantity output by the model: ‘lum’ or ‘flux’

static t_max(p, kappa=1.0)[source]

The maximum time at which the model is valid

\(t_\mathrm{max} = (7.4\,\mathrm{d}) \left(\frac{R}{κ}\right)^{0.55} + t_\mathrm{exp}\) (Eq. 24)

static t_min(p, kappa=1.0)[source]

The minimum time at which the model is valid

\(t_\mathrm{min} = (0.2\,\mathrm{d}) \frac{R}{v_s} \max\left[0.5, \frac{R^{0.4}}{(f_ρ M κ)^{0.2} v_s^{-0.7}}\right] + t_\mathrm{exp}\) (Eq. 17)

units = [<Quantity 3.16227766e+08 cm / s>, Unit("solMass"), Unit("solMass"), <Quantity 1.e+13 cm>, Unit("Mpc"), Unit("mag"), Unit("d")]

A list of the units for each parameter

class lightcurve_fitting.models.ShockCooling4(lc=None, redshift=0.0)[source]

Bases: Model

The shock cooling model of Morag, Sapir, & Waxman (https://doi.org/10.1093/mnras/stad899).

\(L(\tilde{t}) = L_\mathrm{br}\left\{\tilde{t}^{-4/3} + 0.9\exp\left[-\left(\frac{2.0t}{t_\mathrm{tr}}\right)^{0.5}\right] \tilde{t}^{-0.17}\right\}\) (Eq. A1)

\(T_\mathrm{col}(\tilde{t}) = T_\mathrm{col,br} \min(0.97\tilde{t}^{-1/3}, \tilde{t}^{-0.45})\) (Eq. A2)

\(\tilde{t} \equiv \frac{t}{t_\mathrm{br}}\), where \(t_\mathrm{br} = (0.86\,\mathrm{h}) R^{1.26} v_\mathrm{s*}^{-1.13} (f_\rho M \kappa)^{-0.13}\) (Eq. A5)

\(L_\mathrm{br} = (3.69 \times 10^{42}\,\mathrm{erg}\,\mathrm{s}^{-1}) R^{0.78} v_\mathrm{s*}^{2.11} (f_\rho M)^{0.11} \kappa^{-0.89}\) (Eq. A6)

\(T_\mathrm{col,br} = (8.19\,\mathrm{eV}) R^{-0.32} v_\mathrm{s*}^{0.58} (f_\rho M)^{0.03} \kappa^{-0.22}\) (Eq. A7)

\(t_\mathrm{tr} = (19.5\,\mathrm{d}) \sqrt{\frac{\kappa M}{v_\mathrm{s*}}}\) (Eq. A9)

Parameters:
lclightcurve_fitting.lightcurve.LC, optional

The light curve to which the model will be fit. Only used to get the redshift if redshift is not given.

redshiftfloat, optional

The redshift between blackbody source and the observed filters. Default: 0.

Attributes:
zfloat

The redshift between blackbody source and the observed filters

nfloat

The polytropic index of the progenitor

Afloat

Coefficient on the luminosity suppression factor (Eq. A1)

afloat

Coefficient on the transparency timescale (Eq. A1)

alphafloat

Exponent on the transparency timescale (Eq. A1)

L_br_0float

Coefficient on the luminosity expression in erg/s (Eq. A6)

T_col_br_0float

Coefficient on the temperature expression in eV (Eq. A7)

t_min_0float

Coefficient on the minimum validity time in days (Eq. A3)

t_br_0float

Coefficient on the \(\tilde{t}\) timescale in days (Eq. A5)

t_07eV_0float

Coefficient on the time at which the ejecta reach 0.7 eV in days (Eq. A8)

t_tr_0float

Coefficient on the transparency timescale in days (Eq. A9)

evaluate(t_in, f, v_s, M_env, f_rho_M, R, t_exp=0.0, kappa=1.0)[source]

Evaluate this model at a range of times and filters

Parameters:
t_infloat, array-like

Time in days

flightcurve_fitting.filter.Filter, array-like

Filters for which to calculate the model

v_sfloat, array-like

The shock speed in \(10^{8.5}\) cm/s

M_envfloat, array-like

The envelope mass in solar masses

f_rho_Mfloat, array-like

The product \(f_ρ M\), where “\(f_ρ\) is a numerical factor of order unity that depends on the inner envelope structure” and \(M\) is the ejecta mass in solar masses

Rfloat, array-like

The progenitor radius in \(10^{13}\) cm

t_expfloat, array-like, optional

The explosion epoch. Default: 0.

kappafloat, array-like, optional

The ejecta opacity in units of the electron scattering opacity (0.34 cm^2/g). Default: 1.

Returns:
y_fitarray-like

The filtered model light curves

input_names = ['v_\\mathrm{s*}', 'M_\\mathrm{env}', 'f_\\rho M', 'R', 't_0']

A list of the parameter names

t_max(p, kappa=1.0)[source]

The maximum time at which the model is valid

\(t_\mathrm{max} = \min(t_\mathrm{0.7\,eV}, 0.5 t_\mathrm{tr})\) (Eq. A3)

\(t_\mathrm{0.7\,eV} = (6.86\,\mathrm{d}) R^{0.56} v_\mathrm{s*}^{0.16} \kappa^{-0.61} (f_\rho M)^{-0.06}\) (Eq. A8)

\(t_\mathrm{tr} = (19.5\,\mathrm{d}) \sqrt{\frac{\kappa M}{v_\mathrm{s*}}}\) (Eq. A9)

t_min(p, kappa=1.0)[source]

The minimum time at which the model is valid

\(t_\mathrm{min} = (17\,\mathrm{min}) R + t_\mathrm{exp}\) (Eq. A3)

temperature_radius(t_in, v_s, M_env, f_rho_M, R, t_exp=0.0, kappa=1.0)[source]
units = [<Quantity 3.16227766e+08 cm / s>, Unit("solMass"), Unit("solMass"), <Quantity 1.e+13 cm>, Unit("d")]

A list of the units for each parameter

class lightcurve_fitting.models.UniformPrior(p_min=-inf, p_max=inf)[source]

Bases: Prior

A uniform prior in the parameter, i.e., \(\frac{dP}{dp} \propto 1\)

logp(p)[source]
lightcurve_fitting.models.blackbody_to_filters(filters, T, R, z=0.0, cutoff_freq=inf, ebv=0.0)[source]

The average spectral luminosity density (\(L_ν\)) of a blackbody as observed through one or more filters

Parameters:
filterslightcurve_fitting.filters.Filter, array-like

One or more broadband filters

Tfloat, array-like

Blackbody temperatures in kilokelvins

Rfloat, array-like

Blackbody radii in units of 1000 solar radii

zfloat

Redshift between the blackbody source and the observed filters

cutoff_freqfloat, optional

Cutoff frequency (in terahertz) for a modified blackbody spectrum (see https://doi.org/10.3847/1538-4357/aa9334)

ebvfloat, array-like, optional

Selective extinction E(B-V) in magnitudes, evaluated using a Fitzpatrick (1999) extinction law with R_V=3.1. Its shape must be broadcastable to T and R. Default: 0.

Returns:
y_fitfloat, array-like

The average spectral luminosity density in each filter in watts per hertz

lightcurve_fitting.models.format_unit(unit)[source]

Use LaTeX to format a physical unit, which may consist of an order of magnitude times a base unit

Parameters:
unitastropy.units.Unit, astropy.units.Quantity

The unit to format

Returns:
unit_strstr

Formatted unit

lightcurve_fitting.models.planck(nu, T, R, dT=0.0, dR=0.0, cov=0.0)[source]

The Planck spectrum for a blackbody source, including propagation of uncertainties

Parameters:
nufloat, array-like

Frequency in terahertz

Tfloat, array-like

Temperature in kilokelvins

Rfloat, array-like

Radius in units of 1000 solar radii

dTfloat, array-like, optional

Uncertainty in the temperature in kilokelvins

dRfloat, array-like, optional

Uncertainty in the radius in units of 1000 solar radii

covfloat, array-like, optional

The covariance between the temperature and radius

Returns:
Lnufloat, array-like

The spectral luminosity density (\(L_ν\)) of the source in watts per hertz

dLnufloat, array-like

The uncertainty in the spectral luminosity density in watts per hertz

lightcurve_fitting.models.planck_fast(nu, T, R, cutoff_freq=inf)[source]

The Planck spectrum for a blackbody source

\(L_ν = 4 π R^2 \frac{2 π h ν^3 c^{-2}}{\exp(h ν / k_B T) - 1}\)

Parameters:
nufloat, array-like

Frequency in terahertz

Tfloat, array-like

Temperature in kilokelvins

Rfloat, array-like

Radius in units of 1000 solar radii

cutoff_freqfloat, optional

Cutoff frequency (in terahertz) for a modified blackbody spectrum (see https://doi.org/10.3847/1538-4357/aa9334)

Returns:
float, array-like

The spectral luminosity density (\(L_ν\)) of the source in watts per hertz

lightcurve_fitting.models.power(base, exp)[source]

Power function that returns zero for any nonpositive base

lightcurve_fitting.speccal module

lightcurve_fitting.speccal.calibrate_spectra(spectra, lc, filters=None, order=0, subtract_percentile=None, max_extrapolate=1.0, show=False)[source]

Calibrate a set of spectra to an observed broadband light curve.

Each calibrated spectrum is saved to a text file that corresponds to the original filename prefixed by photcal_.

Parameters:
spectralist

List of filenames containing the spectra

lclightcurve_fitting.lightcurve.LC

Photometry table containing the observed light curve

filterslist, optional

Only use this subset of filters for calibration

orderint, optional

Polynomial order for the calibration function. Default: 0 (constant factor)

subtract_percentilefloat, optional

Subtract flux corresponding to this percentile of the spectrum before calibration. Default: no subtraction

max_extrapolatefloat, optional

Assume constant flux in a filter for this many days after the last observed point. Default: 1 day.

showbool, optional

Plot the observed light curve and the uncalibrated and calibrated spectra, and ask whether to save the results

Returns:
figmatplotlib.pyplot.Figure

If show=True, the Figure object is returned

lightcurve_fitting.speccal.convert_spectrum_units(wl, flux, hdr, default_bunit='erg / (Angstrom cm2 s)', default_cunit='Angstrom')[source]

Convert a spectrum to standard units, if information is available in the header to establish units (BUNIT & CUNIT1)

Parameters:
wl: array-like

Input wavelengths

flux: array-like

Input fluxes

hdr: dict-like

Metadata from which to determine the units of wl and flux

default_bunit: str, optional

Units of the output flux. Default: ‘erg / (Angstrom cm2 s)’

default_cunit: str, optional

Units of the output wavelengths. Default: ‘Angstrom’

Returns:
wl: numpy.ndarray

Input wavelengths converted to default_cunit

flux: numpy.ndarray

Input fluxes converted to default_bunit

lightcurve_fitting.speccal.create_wiserep_tsv(specpaths, wiserep_dir, verbose=False, instruments=None, date_fmt='iso')[source]

Prepares a TSV file for uploading spectra to WISeREP (see https://www.wiserep.org/content/wiserep-getting-started).

Also copies all the spectrum files to a single directory, and converts any FITS files to ASCII.

Parameters:
specpaths: list

List of paths to the spectrum files. Optionally, data quality can be specified in a tuple, e.g., [(filename1.fits, 3), (filename2.txt, 2), …], where the second element is 1 (low), 2 (medium), or 3 (high).

wiserep_dir: str

Directory in which to collect the spectra. If it already exists, it will be deleted and remade. The TSV file will be saved alongside this directory using the same name but with a ‘.tsv’ extension.

verbose: bool, optional

If True, print a message when any file is copied or created.

instruments: dict, optional

A dictionary of known instruments. The keys are the instrument from the header and the values are the wiserep instrument ids from https://www.wiserep.org/aux. By default the script builds this dictionary on the fly.

date_fmt: str, optional

Format for the Obs-date column in the output. WISeREP accepts ‘iso’ (default) or ‘jd’.

lightcurve_fitting.speccal.readOSCspec(filepath)[source]

Read spectra from a JSON file in the Open Astronomy Catalog schema (https://github.com/astrocatalogs/schema)

Parameters:
filepathstr

Path to the JSON file containing the spectra

Returns:
filenameslist

List of filenames corresponding to each spectrum

timeslist

List of astropy.time.Time when each spectrum was observed

tellist

List of telescope names (if given) where each spectrum was observed

instlist

List of instrument names (if given) with which each spectrum was observed

wllist

List of wavelength arrays for each spectrum

fxlist

List of flux arrays for each spectrum

scaleslist

List of scaling factors for each spectrum (all ones for the OSC)

lightcurve_fitting.speccal.readfitsspec(filename, header=False, ext=None)[source]

Read a spectrum from a FITS file

Parameters:
filenamestr

Filename from which to read the spectrum

headerbool, optional

If True, also return the FITS header

extint, str, optional

FITS extension number or name in which the spectrum is stored

Returns:
wlarray-like

Wavelengths, typically in ångströms

fluxarray-like

Observed fluxes in erg / (s cm2 angstrom), if units are identifiable

hdrastropy.io.fits.header.Header, optional

FITS header, returned if header=True

lightcurve_fitting.speccal.readspec(f, verbose=False, return_header=False)[source]

Read a spectrum from a FITS or ASCII file and try to identify where and when it was observed

Parameters:
fstr

Filename from which to read the spectrum

verbosebool, optional

If True, print the date and filename of the spectrum

return_headerbool, optional

If True, return the full header as an additional return value

Returns:
xarray-like

Wavelengths, typically in ångströms

yarray-like

Fluxes in erg / (s cm2 angstrom), if units are identifiable

dateastropy.time.Time

Time at which the spectrum was observed, if identifiable (otherwise None)

telescopestr

Name of the telescope at which the spectrum was observed, if identifiable (otherwise '')

instrument: str

Name of the instrument used to observe the spectrum, if identifiable (otherwise '')

hdrdict-like

If return_header=True, metadata is returned as a FITS header or dictionary (for ASCII files)

lightcurve_fitting.speccal.remove_duplicate_wcs(hdr, keep_number=0)[source]

Remove duplicate world coordinate system header keywords from a astropy.io.fits.header.Header

lightcurve_fitting.speccal.removebadcards(hdr)[source]

Remove problematic entries from a astropy.io.fits.header.Header