Messages

SNEWS 2.0 makes use of the fact that hop-client module supports adding custom message formats as plugins. The base class SNEWSBase inherits hop-client’s external message model. For documentation hop-client custom message plugins, see https://hop-client.readthedocs.io/en/latest/user/models.html. SNEWSBase contains the field “message_id” for the purpose of recording and tracing messages for SNEWS usage.

Observation Message

On top of SNEWSBase, an observation message is sent by a detector upon observation possible pre-supernova phenomenon. The observation message has the following additional attributes

  • detector_id: a unique string id of the detector

  • sent_time: the string format of the sending time of the message

  • neutrino_time: the string format of the neutrino time recording by the detector

  • machine_time: the string format of the machine time of the detector

  • location: a string of the location of the detector

  • p_value: a number indicating the P value of the observation

  • status: “ON” or “OFF” indicating the status of the detector

  • content: a string of any additional information of this observation

These attributes are required when a detector constructs a new observation message. An observation message is initialized by

SNEWSObservation(
        message_id=...,
        detector_id=...,
        sent_time=...,
        neutrino_time=...,
        machine_time=...,
        location=...,
        p_value=...,
        status=...,
        content=...,
    )

with alert messages and heartbeat messages alike.

Alert Message

When SNEWS 2.0 determines that a possible supernova is about to happen, it sends an alert message to all experiment detectors with optional instructions. An alert message has the following attributes:

  • sent_time: a unique string id of the detector

  • machine_time: the string format of the machine time of the detector

  • content: a string of any additional information of this observation

Heartbeat Message

All detectors regularly publishes heartbeat messages to tell SNEWS 2.0 server that they are online. A heartbeat message consists of the attributes:

  • detector_id: a unique string id of the detector

  • sent_time: the string format of the sending time of the message

  • machine_time: the string format of the machine time of the detector

  • location: a string of the location of the detector

  • status: “ON” or “OFF” indicating the status of the detector

  • content: a string of any additional information of this observation