[ubuntu] Ubuntu crashing randomly with log messages

Hi,
I have ubuntu 18.04.3 LTS Installed on a lenovo laptop with intel graphic card, recently the pc is rebooting randomly after about half hour or more of use,
Below the syslog messages I am getting after the crash:
Any Idea how to proceed?
Thanks

Code:

[ OK ] Reached target Host and Network Name Lookups. [ OK ] Started Restore /etc/resolv.conf if the system crashed before the opp link was shut down. [OK ] Started Save/Restore Sound Card State. [ OK ] Started LSB: Speech Dispatcher. [ OK ] Started System Logging Service. [ OK ] Started Avahi MDNS/DNS-SD Stack. [ OK ] Started Bluetooth service. [ OK ] Started Thermal Daemon Service. Starting Hostname Service... Starting Authorization Manager… [OK] Reached target Bluetooth. [OK] Started Make remote CUPS printers available locally. [OK ] Started Hostname Service. [OK] Started LSB: automatic crash report generation. [ OK ] Started WPA supplicant. Started LSB: Record successful boot for GRUB. [OK ] Started Detect the available GPUs and deal with any system changes. Starting Manage, Install and Generate Color Profiles... [OK ] Started LSB: Starts and stops Wicd. OK ] Started Authorization Manager. [OK ] Started Accounts Service. [ OK] 1 Started Modem Manager. [ OK ] Started Dispatcher daemon for systemd-networkd. [ OK] Started Disk Manager. [ OK ] Started Manage, Install and Generate Color Profiles. [ OK ] Started Network Manager. Starting Network Manager Wait Online... OK 1 Reached target Network. [ OK ]Started Unattended Upgrades Shutdown. Starting OpenBSD Secure Shell server... Starting Permit User Sessions… [ OK ]Started Permit User Sessions. Starting Hold until boot process finishes up... Starting GNOME Display Manager.. [ OK ]Started Hold until boot process finishes up. Starting Set console scheme... [ OK ]Started Set console scheme. [ OK ]Created slice system-getty.slice, Starting Network Manager Script Dispatcher Service... UK 1 started GNOME Display Manager, UK 1 Started Network Manager script Dispatcher Service. [ OK ]Created slice User Slice of gdm. Starting User Manager for UID 121,,, 1 [ OK ]started session cl of user gom, [ OK ]started User Mariager for UID 121, [ 3896.458533) athiok oci 0000:01:00.0: failed to receive initialized event from target: 00000000 [ 3899.487303) athiok_bci 0000:01:00.0: failed to receive initialized event from target: 00000000