By / par Bryan Gaensler (U. Toronto, CIRADA Director)
(Cassiopeia – Spring / printemps 2022)
The Canadian Initiative for Radio Astronomy Data Analysis (CIRADA), a pilot project for Canada’s planned Square Kilometre Array Regional Centre, is producing science-ready public data products for large surveys being conducted with three telescopes: the Very Large Array (VLA), the Australian Square Kilometre Array Pathfinder (ASKAP), and the Canadian Hydrogen Intensity Mapping Experiment (CHIME). These products (e.g., images, cubes, time series spectra, catalogues, databases, alerts, pipeline algorithms, and software tools) utilise Canadian Advanced Network for Astronomical Research (CANFAR) services and will be searchable and usable by professional astronomers and the general public, through the Canadian Astronomy Data Centre (CADC). Users of our science-ready data products will be able to leverage for viewing images data and tabular catalogues directly through our portal. Currently our services include:
- A “Quicklook Catalogue” of 1.7 million radio sources from the first epoch of the VLA Sky Survey (VLASS) including a second version that contains data on sidelobe probabilities, as well as the software pipelines that were used to generate the catalogues along with detailed user manuals. Next steps: Our team is currently in the process of producing an updated version of the catalogue using updated first epoch images that have had astrometry corrections made as well as a first catalogue using images from the second epoch. Both catalogues will be available in Q2 2022. We are also planning to co-release a VLASS Single Epoch catalogue when the first 1000 square degrees become available in Q3 2022.
- pyink, developed in collaboration with Dr. Tim Galvin, a tool that simplifies the preprocessing and analysis that is required to train a self-organising map (SOM) using PINK. pyink can be used (i) to produce catalogues of double and multiple radio sources, (ii) to classify radio sources as either complex or simple sources, (iii) to find source orientations, and (iv) as an annotation tool. Next steps: Our team has recently hired a new developer to explore opportunities to use this tool to expand the identification of complex sources.
- An Image Cutout Provider that allows astronomers to quickly visualise data from multiple surveys (VLASS Quicklook, GLEAM, FIRST, NVSS, WISE, PanSTARRS, SDSS I-II) at a given position in the sky and to download the data for further analysis. (PLEASE NOTE THAT THE ASTROMETRIC ERRORS THAT WERE PREVIOUSLY REPORTED ARE NOW RESOLVED.) Next steps: We are in the process of extending the application of our cutout provider for use with RACS, VLASS Single Epoch, and VCSS.
- The RM-Tools software package for radio polarimetry analysis, including 1D and 3D RM synthesis, RM-clean and QU fitting on polarised radio spectra. Next steps: Our team is currently adding complementary tools and working on an RM Standards package which will be released in the coming months. We are collaborating with POSSUM scientists, CADC and the Australian Square Kilometre Array Regional Centre on a pipeline to mosaic, re-tile, re-grid and perform ionospheric corrections on POSSUM cubes that can be used to generate Faraday depth cubes and other science-ready data products using the RM synthesis tools.
- Hydra: a source finder comparison and analysis tool that can be used to compare multiple source-finding algorithms on radio continuum data along with examples and detailed instructions.
- A mock-cube generator suite that can be used to generate realistic data cubes for a single galaxy model, or a suite of galaxy models generated from standard scaling relations. Next steps: Our team is coordinating efforts with the WALLABY survey to co-release pilot observations of the Hydra, Norma, and NGC 4636 fields and rotating disk models which will be accessible for download or for use with CADC TAP services through our portal
- An alpha-version of the VLASS Transient Marshal is currently being readied for testing, with a full release planned before the end of the year.
Access to all of CIRADA’s services, software tools and data products is available at cirada.ca.
