Lensed

Reconstruct gravitational lenses and lensed sources from strong lensing observations.

Information regarding Lensed can be found on the website and project on GitHub. The main documentation contains detailed instructions on how to set up, run, configure and extend the code.

This project aims to be a community effort, and we are happy for any and all contributions. The easiest part to play is to open issues whenever something does not work, and create pull requests whenever you have fixed something that was broken. Contributions in the form of new models are most welcome if they are generally useful.

Installation

Pre-compiled binary distributions of Lensed are available for the official release versions, found on GitHub. More information can be found in the documentation.

There are a number of ways to get source distributions of the code, please see the documentation.

Building

Lensed is a simple Makefile project. If all dependencies are satisfied and installed into the system, it should be possible to compile Lensed by simply calling

$ make

from the root of the source directory. For further information, please refer to the documentation.

Usage

The usual invocation of Lensed is with a configuration file which contains program options and the model that is being reconstructed. The reconstruction is started using

$ lensed config.ini

where config.ini is the name of the configuration file.

It is possible to split the configuration into different files, for example to modularise options and individual aspects of the model. The following command would run Lensed with the configuration taken from three different files:

$ lensed options.ini lens.ini sources.ini

Repeated options are overwritten by the later configuration files.

Finally, it is possible to give any of the options (but not the model) directly on the command line. For example, in order to change the number of live points for a quick look at results, one could invoke Lensed in the following way:

$ lensed config.ini --nlive=50

As before, the order of the given configuration files and options is important.

If Lensed is built with XPA support or taken from a binary release, direct updating of the reconstruction progress in SAOImage DS9 is available.

$ lensed config.ini --ds9

The --ds9 option enables basic DS9 integration in Lensed. The flag can be set from a configuration file as well.

License

The Lensed source code can be freely modified and distributed under the terms of the MIT license. The authors also kindly ask that any and all scientific work which benefits from this software cites the relevant articles.

This software makes use of the following libraries from third parties:

• MultiNest, copyrighted by Farhan Feroz and Mike Hobson, with some limitations (especially for commercial use)
• CFITSIO

Please see the licenses file for copyright information.

Versions

The Lensed project uses a form of semantic versioning.

Given a version number MAJOR.MINOR.PATCH, Lensed increments the

1. MAJOR version for changes that render input files incompatible,
2. MINOR version for changes that leave input files compatible but might lead to changes in results, and
3. PATCH version for bugfix changes that do not alter results, unless the results are affected by the bugs fixed.

By comparing the output of lensed --version before installing a different version of the code, the user can anticipate whether updates could possibly break existing models or alter the results of a reconstruction.