Metallicity estimation of RR Lyrae stars from their I-band light curves

This repository contains the data files and codes for the basic workflow of the following study: Dekany, Grebel, & Pojmanski (2021)

The codes have been developed under the following python environment:

python 3.8
numpy 1.19.5
theano 1.1.2
PyMC3 3.11.2
arviz 0.11.2
matplotlib 3.4.2
scikit-learn 0.24.2
joblib 0.24.2

Installation

Simply copy the files into a desired folder and run the .py files with a suitable python interpreter (see above):

python <filename>.py

Description of the files

Source codes

ifeh_io.py

Contains static method (function) definitions required by the rest of the codes.

ifeh_rfe_sfs.py

Executable script for the computation of the optimal feature sets. See Sect. 3.1 of the paper for details. The input/output file names and parameters must be set in the source code's preamble.

ifeh_mcmc_rrab.py

Executable script for fitting the Bayesian regression model of the metallicity for the RRab stars. See Sect. 3.2 of the paper for details. The input/output file names and parameters must be set in the source code's preamble.

ifeh_mcmc_rrc.py

As above, but for the RRc stars.

compute_mdfs.py

Executable script for the computation of the RR Lyrae metallicity distribution functions (MDFs) of the following cosmic environments: inner and outer bulge, bulge/disk transition region, southern Galactic disk, Sagittarius dwarf spheriodal galaxy, halo, Small and Large Magellanic Clouds. See Sect. 4 of the paper for details. The input/output file names and parameters must be set in the source code's preamble.

Data files

CHR_X_phot_single.dat, LIT_hires_feh_1_X_phot.dat, LIT_hires_feh_2_X_phot.dat

Files containing individual spectroscopic metallicities and light-curve parameters of the objects in the development data set collected from the literature. See the column headers for more information. The columns feh0, feh1, e_feh0, e_feh1 contain the metallicity values derived from the FeI and FeII lines, and their quoted uncertainties, respectively (where available). The columns feh and e_feh contain the metallicities and their unceratinties used in our study. Note that wherever possible, e_feh represents the square root of the pooled variance of the measurements computed for author+instrument pools (see Sect. 2.2 of the paper for details). Note that the column shift (see Sect. 2.2) must be added to feh. Gaia identifiers and coordinates correspond to Data Release 2 (DR2).

o4rrabparam.dat, o4rrcparam.dat

Files containing the I-band light-curve parameters of the RRab and RRc stars in the OGLE Collection of Variable Stars including data from the OGLE-IV survey. See Sect. 2.1 of the paper for details. These data are used for the computation of the MDFs in Sect. 4.

o4rrab_bulge_v_gpr_dff_param.dat

V-band light-curve parameters of the bulge RRab stars in the OGLE Collection of Variable Stars including data from the OGLE-IV survey. These data are used by compute_mdfs.py to make comparisons of the MDFs across various I- and V-band estimators.

idekany/ifeh