Latest BPASS version 2.2 Data Release (May 2018)

This version of BPASS represents an extension and modification of our v2.1 and older models.

The more important new features and results included in this release of BPASS include: calculation of a significantly larger number of stellar models, release of a wider variety of predictions of stellar populations including Lick indices, inclusion of new stellar atmosphere models, improvements in the treatment of low mass stars, and modified binary parameter distributions. These result in significantly better handling of old stellar populations

BPASS v2.1 was fully described in a peer-reviewed paper: Eldridge, Stanway et al, 2017, PASA 34 58.

This data release, v2.2, builds on the detailed modelling described in that paper, but includes improved or modified prescriptions in some areas. These are described and results presented in Stanway & Eldridge (2018, MNRAS in press).

We have also produced an updated User Manual which we strongly recommend users examine. This is available typeset in both Arial and OpenDyslexic (a font designed for use by those with specific learning differences).

The data release is routinely stored on Google Drive at


Filenames have now been updated to incorporate IMF names as described in the user manual. We caution that the full data release is very large (particularly if individual stellar models are downloaded). It comprises a directory structure, sorted by IMF, with tarballs containing data products as follows:

1. Stellar Model Outputs:

  • Binary stellar models with photometric colours
  • New OB stars atmosphere models

2. Stellar Population Outputs (all versus age):

  • Massive star type number counts
  • Core collapse supernova rates
  • Yields, energy output from winds and supernovae and ejected yields of X , Y and Z
  • Stellar population mass remaining
  • HR diagram (isochronal contours)

3. Spectral Synthesis Outputs (all versus age):

  • Spectral Energy Distributions
  • Ionizing flux predictions
  • Broadband colours
  • Lick Indices
  • Mass to Light Ratios
  • Colour-Magnitude Diagram (CMD) making code

For full details, and README details for the data files, we again recommend the User Manual.

We would appreciate the inclusion of the following acknowledgement where appropriate:
“This work made use of v2.2 of the Binary Population and Spectral Synthesis (BPASS) models as described in Eldridge, Stanway et al. (2017) and Stanway & Eldridge et al. (2018).”

For the Xiao, Stanway & Eldridge (2018) nebular gas emission models (based on BPASS v2.1) please see our nebular emission sub page.

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