What log is 'Received SIGHUP restarting'?

'Received SIGHUP restarting' occurred and why does this log occur? I will attach relevant log data. Thank you.

KC_IPCC_L7_1/40.246.109.241 err: sshd[18072]: error: PAM: User not known to the underlying authentication module for sscard from 182.198.156.34 KC_IPCC_L7_1/40.246.109.241 info: sshd[18075]: Received disconnect from 182.198.156.34: 11: The user disconnected the application KC_IPCC_L7_1/40.246.109.241 err: sshd[18079]: error: PAM: User not known to the underlying authentication module for sscard from 182.198.156.34 KC_IPCC_L7_1/40.246.109.241 info: sshd[18082]: Received disconnect from 182.198.156.34: 11: The user disconnected the application KC_IPCC_L7_2/40.246.109.242 info: sshd[5803]:

Received SIGHUP; restarting.

version : 11.5.1 HF10