Fink filters

What is a Fink filter?

Each night, telescopes are sending raw alerts and Fink enriches these alerts by adding new information to identify interesting candidates for follow-up observations or further scientific processing (see Fink Science Modules). Defining what is considered interesting varies significantly from person to person, as individual scientific interests and curiosities differ widely. Recognizing this, our strategy focuses on enabling users to extend Fink by incorporating their unique scientific logic and receive tailored outputs that align with their own perspectives.

To facilitate this personalization, we have introduced the concept of Fink Filters, which allow users to receive alerts of interest by imposing conditions on any fields produced by Rubin or any of the Fink Science Modules outputs provided by the community of users. Their code can be found in the fink-filters code repository

graph LR
  A(N incoming alerts) ==> B(((Fink filter)));
  B --> D(M << N outgoing alerts);
  D --> E((Telegram/Slack and fink-client))

Note that if the filters reduce the size of the stream, they do not filter the content of alerts, i.e. you will receive the full information of alerts distributed (unless you want less!).

Fink blocks

Some set of conditions are common to many scientists: alerts away from the galaxy, with or without a counterpart with some catalogs, etc... Therefore we provide common blocks, the Fink blocks, to ease the construction of filters. Their code can be found in the fink-filters code repository, and they are also exposed in the schema page .

Retrieving data from filters

Kafka streams

As we process alerts, interesting alerts are automatically picked up by filters and Apache Kafka queues are populated. Each stream from a particular filter is identified by a topic name. This stream can be accessed outside via its topic, and several users can poll the data independently from the same topic. All topics can be accessed using the Fink client , which is a wrapper around Kafka consumer functionalities (see Livestream documentation).

REST API & Science Portal

Fink bots

In addition, for some filters, we redirect the data to instant messaging services such as Telegram or Slack (just ask for it if you need other platforms!). Below we summarise the widely used Fink topics, with their availability on Slack and Telegram (for Telegram, you can directly subscribe using the link or the QR code below).