PyRIME: Rectified I-band Metallicity Estimae of rr lyrae variables

This routine calculates the I-band photometric iron abundance of RR Lyrae variables, based on Equation 3 of Smolec (2005), but correcting for the amplitude-dependent offset in the Oosterhoff I variables, as described by Hajdu et al. (2018).

This routine was developed for:

• Python 2.7+ or 3.6+
• Numpy 1.12+

Installation

Copy all files from the bin directory to the same directory in the system PATH. If you get "ImportError: No module named builtins" error while using Python 2.7, install the future package.

Usage

The only argument the program expects is the location of a file, containing at least five columns, where the first five columns should be:

• NAME: the name of the variable
• PERIOD: the period of the variable
• A1: the amplitude of the first Fourier harmonic in the I band
• A2: the amplitude of the second Fourier harmonic in the I band
• phi31: the epoch independent phase difference of the first and third Fourier harmonics in the I-band

Given these data, the routine estimates whether a variable belongs to the Oosterhoff II group, in which case the original Equation 3 is used to calculate its iron abundance. In case of Oosterhoff I variables, the amplitude dependence is rectified as described in Hajdu et al. (2018).

Finally, the program outputs the name of the variable, the abundance estimate and whether it is an Oosterhoff I or II variable.