Catalyst 3650 and flash core directory

Hi guys!

I'm needing to upgrade a 3650 and I'm memory short. Seeking where is the shit, I found that I have a lot of this:

hostname#dir Directory of flash:/core/ 85361 drwx 4096 Dec 20 2017 19:50:25 -03:00 modules 38814 -rw- 1 Dec 27 2019 11:32:57 -03:00 .callhome 38818 -rw- 5139267 May 20 2019 12:32:20 -03:00 hostname_1_RP_0_nginx_11572_20190520-123208-CHI.core.gz 38819 -rw- 4673333 May 20 2019 12:32:31 -03:00 hostname_1_RP_0_nginx_29257_20190520-123220-CHI.core.gz 38820 -rw- 4672672 May 20 2019 12:32:42 -03:00 hostname_1_RP_0_nginx_29549_20190520-123231-CHI.core.gz 38821 -rw- 4673332 May 20 2019 12:32:53 -03:00 hostname_1_RP_0_nginx_29746_20190520-123242-CHI.core.gz 

There's a lot of this files (around 800 MB of those) and I can't find info about what they are and if I can delete them.

Inside each of those .gz files there is one binary file with extension .core

Does any of you have any idea about this?