Digesting Astronomical Sky Survey Alerts

FRITZ: Front-end for Reviewing Interesting Transients in ZTF Phase-II

PI: Tom Prince and Shri Kulkarni (PMA Division)
SASE: Kyung Min Shin, Scholar

The Zwicky Transient Facility (ZTF) is a next-generation astronomical sky survey currently in operation using the Palomar 48-inch Schmidt Telescope. Fitted with a state-of-the-art camera and observing system, ZTF provides an order of magnitude improvement in survey speed relative to its predecessor survey (the Palomar Transient Factory). The ZTF is able to survey the entire Northern visible sky every couple of nights. Near-real-time data reduction via the ZTF Science Data System at Caltech's Infrared Processing and Analysis Center (IPAC) provides the ability to quickly identify interesting astronomical objects and alert researchers in a timely manner. These data alerts sent out by IPAC must be ingested, filtered, and managed via software to allow astronomers to garner insights from them.

The Schmidt Academy for Software Engineering collaborated with the ZTF team on the FRITZ project (Front-end for Reviewing Interesting Transients in ZTF-II) - the main portal into the downstream scientific data provided by the ZTF survey. Incorporating modern software tools/practices such as a React-Redux web application, a Python/PostgreSQL driven API, and a MongoDB data archive, FRITZ aims to provide a modular and extensible environment for review of alerts produced by ZTF. To this end, FRITZ combined builds on two open-source projects. FRITZ's Kowalski data archive persists and curates the ZTF alert data and executes user-defined filters to produce the streamlined information to be consumed by the user-facing web application. SkyPortal is the extensible web application and API allowing astronomists to analyze and follow up on the cleaned up ZTF alerts.

The Academy has assisted in the development of all components of the FRITZ project, helping to make it an industry-standard software meeting all functional requirements. FRITZ has now replaced its predecessor GROWTH Marshal as the main platform of collaboration for ZTF astronomers, with over 200 active users. It has garnered interest from researchers from other surveys for adaptation to non-ZTF use cases as well, and is growing larger day by day.

Important links to the software and documentation can be found on the web.

For FRITZ Documentation:
For some of the software:
The resources can be accessed through the SkyPortal app:


Accessing FRITZ through a Tablet.