Where does Oracle Enterprise Manager derive the "User Logon Time" metrics from?

Oracle's enterprise manager has a metric named "User Logon Time" and will show an alert if that exceeds a certain threshold. I would like to retrieve the numbers stored for this metrics directly using a SQL query. However, I cannot find any view where this is stored. I can find "Logons Per Sec", "Logons Per Txn", "Current Logons Count" in the DBA_HIST_SYSMETRIC_SUMMARY view and "logons cumulative" and "logons current" in the DBA_HIST_SYSSTAT view. The view DBA_HIST_METRIC_NAME also doesn't list any metric of that name. So where does the Enterprise Manager get that information from? I'm talking about this alert: