how i can set the newly created Group as self-owner inside my event reciever

I am working on sharepoint 2013 server , and i have the following event reciever where i am creating new user group inside a sub-site:-

public override void ItemUpdated(SPItemEventProperties properties)
    {

    base.ItemUpdated(properties);

	var currentusername = properties.UserLoginName;
	site.RootWeb.SiteGroups.Add(curItemSiteName, site.RootWeb.SiteUsers[@"domain\" + currentusername], site.RootWeb.SiteUsers[@"domain\" + currentusername], "Some description");
	SPRoleAssignment ra = new SPRoleAssignment(site.RootWeb.SiteGroups[curItemSiteName]);
	ra.RoleDefinitionBindings.Add(site.RootWeb.RoleDefinitions["Contribute"]);
	newSite.RoleAssignments.Add(ra);
	site.RootWeb.RoleAssignments.Add(ra);
        site.RootWeb.Update();
	}

but i m not sure how i can do these 2 modifications:-

1. from the UI i can set these 2 options when creating a new user group:-

so is there a way to do so using my above code?

2. currently i am adding the user who executed the event receiver as the "Group Owner"... but my question is how i can modify my above code to assign the newly create group as the "Group Owner". in other word members of the Group will be the "Group owners"??