Coma Factory: A Suite of Tools to Simulate, Analyze, and Interpret Features in Cometary Comae

We propose to develop a suite of tools to simulate, analyze, and help interpret coma features present in images of comets. These software tools will assist scientists to characterize coma properties and by extension the nuclei of comets. A wide range of new software will be developed in order to analyze and characterize the images, complementing the existing software developed by us. The software tools will be made available as a web facility and also as software modules that users can download and run on their computers or integrate into their own software.

The coma simulation models use Monte Carlo techniques. The trajectories and locations at a given instant for the particles sampled will depend on a number of physical parameters. Such parameters define the source location of the particles on the nucleus, initial outflow velocities, rotational state of the nucleus, and lifetimes of the particles. The images generated by the models are based on observational geometries and characteristics of the imaging instrument and therefore mimic the actual observations. The simulations will generate images corresponding to different kinds of observations: (a) distant (e.g., Earth-based observations with unresolved nucleus) and (b) close by (e.g., spacecraft observations with resolved nucleus).

The model images will be in FITS format, the standard format for the majority of astronomical observations. Generation of such model images will benefit the user, as images can be digitally enhanced with the same technique that was used to enhance the actual observations. This allows for a realistic comparison between observations and models. The web facility will be capable of generating model coma images based on user-provided inputs. For comparison with observations, the user will also be allowed to download the model images from the web facility.

To complement coma simulation software, we will develop additional software to analyze and characterize the three-dimensional and two-dimensional structure of the coma for simulated images as well as for actual observations as relevant. These include appropriate display tools with capabilities to analyze the coma structure. This software will allow the user to measure and quantify the brightness distribution, characterize the features, and monitor temporal and spatial evolution of the comae.

The proposed web facility will include relevant documentation, including tutorials, as well as access to source codes. In addition, source codes and related documents will be archived at NASA’s PSD GitHub site and other relevant archives.

The proposed work will benefit from our experience in developing a web interface to digitally enhance coma images of comets (made available at the URL https://www.psi.edu/research/cometimen). Many professional and amateur astronomers have used that site for their research. The proposed facility will provide a web-based resource easily accessible to the community to interpret observations of many comets. It will be a facility that can be accessed from any computer and accessibility is independent of the operating system and/or the browser. The user-friendly interface will enable the user to use the tools even if the user is not familiar with the language (Python) the source codes are written in. The source codes will be made available to the community.