ebpetroff / frb_voevent

A VOEvent standard for fast radio bursts

FRB_VOEvent

A VOEvent standard for fast radio bursts

In this repository you will find the most up-to-date information about FRB VOEvents: why use them, how to make them, and how to receive them.

What is a VOEvent?

A VOEvent is a communication standard developed by the Virtual Observatory to send information on short timescales about new astronomical events. A VOEvent is an xml schema that contains important/relevant information about a new event so that others around the world can follow up and take more data after the event has been reported. You can read more about the VOEvent concept here

A VOEvent contains a few different elements to break up the information into a few different categories:

• Who is issuing the event?
• What is the event of interest?
• Where/When did the event occur?
• Why should this event be followed up?

VOEvents are sent over the VOEvent network. They are issued by an author using a broker and are either received by a subscriber or received and then re-transmitted by an intermediary broker and then received by the subscribers to the second broker.

Why VOEvents?

VOEvents allow you to communicate very quickly with other people listening in to the network around the world. The events themselves are machine generated and machine parsable (see below) so they are ideal for robotic telescopes or for real-time search pipelines that operate with minimal or no human intervention.

Why VOEvents for FRBs?

There are a lot of reasons why we believe VOEvents are really great for FRB detection and follow-up. There are so many reasons, in fact, that we wrote a paper! Please read the paper in this repository (FRB_VOEvent_Paper_*.pdf) for the details of the FRB VOEvent standard and the justification behind FRB VOEvents. All the parameters used in these events are defined in parameter_definitions.pdf and a table schematic of where these parameters are used and/or required is provided in the parameter_table.pdf document.

Interacting with VOEvents

VOEvents are xml files, meaning you can just interact with them by editing the text they contain. That's not the nicest way, though. There are great tools that have already been created for manipulating and interacting with VOEvents in python. The one used here and in many implementations is voeventparse. You can learn more at the voeventpares tutorial page.

This is as far as you need to read if you were just interested in VOEvents in general. If you're more specifically interested in FRB VOEvents keep reading!

Authoring an FRB VOEvent

This repository contains tools for creating FRB VOEvents. The templates directory contains blank VOEvents of all the different types described in the paper. The examples directory contains a few simple examples of what a detection and update event would look like for a given FRB. The (SCRIPTS) directory contains some basic scripts for creating a basic detection FRB message. The READMEs in the different directories contain more information about usage.

Issuing your VOEvent

The FRB Catalogue (FRBCAT) will very soon run a broker service which can receive and re-broadcast FRB VOEvents to a list of subscribers. FRB VOEvents that are sent to the FRBCAT broker will also be automatically added to the catalogue (see the FRB VOEvent paper for more information).

To broadcast a VOEvent you will need a broker. We recommend the Comet broker which is commonly used for VOEvent communication. To avoid reinventing the wheel, we haven't included any Comet tutorials here, but instead refer you to the excellent start up guide that already exists.

The FRBCAT VOEvent broker receives events at the port phobos.astron.nl:8098. Your IP address must be whitelisted for transmitted events to be parsed and processed. To register your IP address with the FRBCAT broker, please contact the administrator (Emily Petroff). Events received by the FRBCAT broker will be parsed and added to the Catalogue and will be re-broadcast from the broadcast port (see below).

Receiving VOEvents from the FRBCAT Broker

The FRBCAT VOEvent broker broadcasts events at the port phobos.astron.nl:8099 to any parties who subscribe. If you are interested in receiving these messages, please add this address to your broker's list of remote broadcasters to which it subscribes.

Parsing a VOEvent

VOEvents are easily parsed using the voeventparse python package. See here for a full tutorial.

frb_voevent's Issues

script needs reference to voevent-parse

We are starting to implement this for realfast. I noticed that the script for generating a voevent refers to an object vp, but that is not defined in the script.
I'm guessing it should import from voevent-parse: https://voevent-parse.readthedocs.io/en/stable/ in the script.