Knockout js dinamically add Viewmodel to master Viewmodel

I need to add dinamically new viewmodel to master Viewmodel.

For example i have this struct:

var masterVm: {
 vm1: {},
 someProp : ko.observable(),
 ...
}

masterVm is refered to main.js and vm1 to another component.js.

I want to add to masterVm a newVm after page of newComponent.js is DOMed and it's script is loaded (by $.getScript() func self-containig code of vm2). I have to do this cause need to share observable var between viewmodel. I'm open also others alternatives.

Thanks in advance.