DOI: 10.24378/exe.5426
title: Variation of the low-mass end of the stellar initial mass function with redshift and metallicity (dataset)

description: This is the dataset that was used to produce a paper published in the Monthly Notices of the Royal Astronomical Society (MNRAS): Bate (2025, submitted Sept 2024). It contains output from each of the twenty SPH simulations. It also includes data produced during the analysis of the calculations to produce the figures appearing in the paper and the Python scripts used to generate the figures. To view the paper itself, follow the associated DOI.
description: This repository contains the datasets from the original smoothed particle hydrodynamics (SPH) calculations for the associated paper (Bate 2025). There are 20 SPH calculations discussed in the paper, each performed using 35 million SPH particles with the same initial gas densities and velocities, but differing in their metallicity and/or the cosmic microwave background radiation (CMBR). The metallicities correspond to solar metallicity (Metal1), 3 times solar metallicity (Metal3), 1/10 solar metallicity (Metal01) and 1/100 solar metallicity (Metal001). The CMBR is that appropriate for redshifts z=0,3,5,7, or 10. The outputs from each calculation are found in the zip files, one for each of the twenty calculations. The initial phases of 7 of the calculations have been reported in two previous papers. Bate (2019) published calculations at z=0 and four different metallicities, with the dataset published on ORE at the DOI:10.24378/exe.1123 available at the handle: http://hdl.handle.net/10871/35993. Bate (2023) published calculations at z=5 and three different metallicities, with the dataset published on ORE at the DOI:10.24378/exe.4324 available at the handle: http://hdl.handle.net/10871/131699. These 7 calculations were continued from 1.20 to 1.30 initial cloud free-fall times for the new paper and the final SPH dump files for each of these calculations are provided in this dataset (files Bate2019_Metal*_Cont.zip and ClusterRedshift5_Metal*_Cont.zip), along with the P-files (see below) from the entirety of each of the calculations. The other 13 calculations were performed for the new paper (four metallicities for each redshift z=3,7,10, but a 3 times solar metallicity calculation at redshift z=5). For example, ClusterRedshift7_METAL01.zip contains input and output files from the calculation with redshift z=7 and 1/10 solar metallicity, including a dump file containing the initial conditions (called CLU0000 at time t=0) and a dump file from the end of calculation at t=1.3 initial cloud free-fall times. The output files for each calculation include ASCII files outputting global properties of the calculation at the times that dump files were written (beginning with the letters "cl"), Fortran binary files (beginning with the letter P) that give sink particle properties throughout the calculations, and Fortran binary files (beginning with the letter A) that contain entries for each particle accreted by a sink particle. The P-files can be read using the Fortran programme included in the repository: ptmass_simple_MPI_2.f . The times of each dump file are recorded in the ASCII output files beginning with “cl”. The SPH dump files (and other Fortran binary files) were written generated by the sphNG code in big endian format except for the calculations at redshift z=3 for which the binary files are written in little endian format. The SPH dump files can be read, visualised, and manipulated using the free, publicly available SPLASH visualisation code (which reads sphNG dump files), written by Daniel Price, that can be downloaded from: http://users.monash.edu.au/~dprice/splash/ Finally, the file BATE2025_FIGURES.zip contains data produced during the analysis of the calculations to produce the figures appearing in the paper, the Python scripts used to generate the figures, and the Fortran code ptmass_simple_MPI_2.f
description: The article which this research data supports is available in ORE at http://hdl.handle.net/10871/139556