showing signals on sequence diagram

[SomersetGraham]

Hi
I am trying to draw a sequence diagram
One of classes emits a signal that is processed asynchronously by another class.
How can I show that the first class is just emitting a signal (it does not care who catches and processes it) on my sequence diagram

Hope this makes sense

Thanks

[Geert Bellekens]

You can send an asynchronous message to an endpoint or a gate.
Or you could create a signal object.

Geert

[Paul Lotz]

As Geert suggests, you can use an asynchronous message.

This works for me to show publish-subscribe messages where I show that EntityA sends a message to which EntityB subscribes.

The challenge are:
a) if I don't want to show the EntityB part.  Then maybe note it like a lost message (although it's really not lost). Or
b) if I want to show EntityB and EntityC receive the same message EntityA sent.  I'm not sure how I would do that on a sequence diagram.

Interesting puzzle.

Paul