User account for Active Directory Trust

Question

Hello,

We have created AD Forest trust between some Domains and found that a user account is created under Users container for each Forest with Domain netbios name like Domainabc$.

I know this account is created when the Domain/Forest trusts are created but this account is having "password not required" we need to understand the use of this account. Can we delete this account after the trust is created. Can we change this account to require password.

I have tried searching a lot but did not find any information in Microsoft sites.

If anyone is aware of this or have any link describing the use of this account then please help