Manually triggering alerts in Alertmanager

[hartfordfive]

I realize that the documentation advises use to only have Prometheus handle triggering alerts in Alertmanager and that clients are expected to resend alerts at least every 30s to 3m while they are active.    I'm curious to know the section in the alertmanager code where this evaluation loop occurs?    Technically speaking, say if we have a client that guarantees it always sends an alert payload to alertmanager every 60s while the alert is active, would this ensure the alert remains active in the alertmanager UI?   

The reason I ask is that in my current position, we primarily use Prometheus to trigger alerts although we have some external monitoring systems for which we must use and unfortunately can't migration into the Prometheus ecosystem.   I would like to continue having a single location where we can silence alerts regardless of our monitoring system, and use that as our source of truth.   

I appreciate your help.