This package was created to aid in measuring radial velocities from stellar spectra by comparing observed spectra to masks based on fiducial absorption spectra.

The class Spectrum processes .fits files containing continuum-normalized spectra. It has modules for constructing a spectrum object from the data and metadata (optionally making a Barycenter-Earth RV correction), and for interpolating over NaN values.

The class Mask reads in a spectral mask from a .csv file and a spectrum in the form of wavelength and flux arrays. It has modules that interpolate the mask and spectrum over all wavelength values and calculate cross-correlation and the cross-correlation function.

The function gaussian_fit fits a Gaussian curve to the cross-correlation function between the spectrum and mask to measure the difference in wavelength.

To use this package, first clone this repository:

git clone https://github.com/elizabethteng/spectralmask.git

then open the spectralmask directory and install it in your python environment:

pip install .

The dependencies should also install automatically.

The notebook tutorial.ipynb included in the main directory contains an explanation of the scientific basis for this package as well a brief tutorial demonstrating the basics of the code. Additional documentation exists in the docstrings of the source code.

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Software project for Northwestern University ASTRON 441 Astronomical Techniques Fall 2022

original coding assignment from ASTRON 421 Observational Astrophysics class, Spring 2022