extrabol
extrabol is a Python 3.x package for rapidly and systematicaly estimating the bolometric luminosity and black body properties of (thermal) extragalactic transients from broadband UVONIR data. extrabol is broken down into three main steps:
- Read in and pre-process a data file holding observations of a supernova or other transient event over time, through any number of broadband filters.
- Interpolate this data using a Gaussian Process(GP), a non-physical, statistical model utilizing covariance.
- Fit a series of blackbody curves to the interpolated data to estimate the bolometric luminosity, temperature, and radius of the transient over time.
Author: Ian Thornton
Installation and Documentation
Install with pip:
pip install extrabolThe latest documentation is available here.
Usage
extrabol 'filename.dat' ARGUMENTS
Optional Arguments:
--verbose
Increase output verbosity
-m MEAN, --mean MEAN
Use a supernova template as the mean function for the GP; Choose \'1a\',\'1bc\', \'2l\', \'2p\', or \'0\' (for no template)
Default = 0
-t, --show-template
Shows supernova template on plots as dotted lines
-d DIST, --dist DIST
Object luminosity distance in Mpc
-z REDSHIFT, --redshift REDSHIFT
Object redshift
If no argument is provided, redshift will be read from the input file
--dm DM
Object distance modulus
--plot BOOL
Output plots, Default is TRUE
--outdir OUTDIR
A file location for outputs to be written to
--ebv EBV
Milky Way extinction E(B-V) value, if known
If no argument is probided the extinction will be read from the input file
--hostebv HOSTEBV
Host extinction E(B-V)
-s START, --start START
Start time of analysis window relative to peak luminosity
Default = -50 days
-e END, --end END
End time of analysis window relative to peak luminosity
Default = 150 days
-snr SNR
Minimum signal to noise ratio for observations
Default = 4.0
-wc, --wvcorr
Use the redshift-corrected wavelength values for extinction calculations
-mc, --use-mcmc
Use a Markov Chain Monte Carlo to fit black bodies instead of curve_fit.
This provides better error estimates but takes much longer.
--T_max T_MAX
Modify the prior on temperature for blackbody fits by specifying a maximum temperature.
Default = 40,000K
Input Files
Inputs to extrabol must be .dat files that conform to the following format.
The first two lines must contain redshift and Milky Way extinction E(b-v) respectively. If these values are unknown, simply put 0.0. The following lines contain observational data in 5 columns as shown below:
Time(MJD) Apparent Magnitude Error(in magnitudes) Filter SVO ID Type of magnitude (AB or Vega)
Any white space can be used as the column delimiter. NaNs, non-detections, and data points with no error bars should not be included. An example input file can be found under extrabol/example.
Example Input
extrabol ./example/PSc000174_extrabol.dat --verbose -m 1aThis example may take a minute the first time you run it as astroquery fetches filter information!
Filters must be specified by their SVO ID.
