Analysing Radio Astronomy Absorption Spectra

RadioAbsTools is a suite of tools for working with radio astronomy absorption spectra. It is written with neutral hydrogen (HI) spectra in mind but should be adaptable to other lines.

Installation and Requirements

RadioAbsTools works with Python 3.6 or later and requires Astropy v3 or later.

For local use it can be installed by downloading the source and then:

cd radioabstools
pip install -e .

RadioAbsTools requires numpy, scipy and astropy.

Usage

cube_tools.py

cube_tools contains methods for extracting spectra from FITS cubes.

spectrum_tools.py

spectrum_tools contains methods for dealing with absorption spectra.

Example Usage:

from RadioAbsTools import spectrum_tools
import numpy as np

velocities = np.arange(10)*1000
fluxes = np.ones((10))*5
fluxes[7:8]=2
fluxes[2]=5.1
spec_mean, spec_sd = spectrum_tools.get_mean_continuum(velocities, fluxes, 1000, 5000)
sigma_opacity = np.ones(velocities.shape)* spec_sd
opacity = fluxes/spec_mean
spectrum_tools.plot_absorption_spectrum(velocities, opacity, 'spectrum.png',
    'Sample Spectrum', 1000, 5000, sigma_opacity)
rating, opacity_range, max_s_max_n = spectrum_tools.rate_spectrum(opacity, spec_sd)

Testing

This module uses pytest for unit testing. To run the tests, use

pytest