Projects

Example uses of SCiMMA
LIGO-Virgo-KAGRA public alerts

  • igwn-alert is a SCIMMA-HOP-based messaging platform used within the LIGO-VIRGO-KAGRA (LVK) collaboration. igwn-alert serves as a bridge between real-time data analysis pipelines and the Gravitational-wave Candidate Event DataBase (GraceDB). It transfers information to and from real-time processes that enable the discovery and public alerting of new gravitational wave candidates.

  • 103 message topics served.

  • 45 active members.

  • 50,000 messages per day.




LIGO-Virgo-KAGRA internal use

  • Within LIGO-VIRGO-Kagra (LVK) Hopskotch is used as an internal messaging component of GraceDB, the gravitational wave candidate event database, which serves as the repository for candidate events from gravitational-wave (GW) searches, and is the source-of-truth for GW analysts and alert follow-up processes.

  • Hopskotch is used to communicate state changes in GraceDB in real time to LVK users and LVK applications. These state changes can be new gravitational wave event uploads, event annotations (attaching data products, such as Skymaps), and superevent creation and annotations.

  • These applications/processes use information in Hopskotch messages (called igwn-alerts) to trigger follow-up gravitational wave analyses and to generate alerts to deliver to outside (non-LVK) observing partners.

  • There are private Hopskotch topics for each corresponding instance of GraceDB (Production, Playground, Test). At any one time, the full system consists of about 35 private topics, including the development and test topics. with all permissions administered within LIGO.




SuperNova Early Warning System (SNEWS)

  • SCiMMA developers led a collaboration with the SNEWS project, an international network of neutrino detectors designed to discover the next galactic supernova. SCiMMA and developers collaboratively developed the SNEWS 2.0 app, which extends the hop-client to receive and process alerts from SNEWS's internal data streams hosted on HOPSKOTCH.

  • A summary and demonstration of the collaboration software is availabe on YouTube

  • The collaboration is detailed in Collaborative experience between scientific software projects using Agile Scrum development written by members from both SCiMMA and SNEWS, and is currently under peer-review (as of March 2022)




Emeritus Use Cases
Astrophysical Multimessenger Observatory Network (AMON)

  • SCiMMA members are involved with the AMON group at the Pennsylvania State University, which began integrating HOPSKOTCH and hop-client into its existing MMA alert processing system. A summary presentation about the integration is available online