Audit logs generated by OEM agent

One of the 11.2.0.4 databases being monitored by OEM13c(13.3.0.0.0) agent generates too many audit logs and filling up the file system.

Auditing of SYS operations parameter is set to TRUE. And, SYS is the user in the monitoring configuration for the DB target. I see some of the audit log files are getting appended every 30 seconds with a SQL statement as follows:

SELECT 1, status, '',archiver, database_status, active_state FROM v$instance

I also find another audit file containing queries and PL/SQL code related to RMAN catalog views. I am sure these are metric collection related activity from the OEM agent.