I do have a simulation for [url=http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=207.0]Mirage[/url].
You can check it out and post your response there if you remains in doubt.

For [b]virtual object[/b], please check out [url=http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=47.0]Thin Lens combinations[/url]
Right click the mouse button in the simulation region, it will become a two lens system.
Those gray lines represent vitrual object.
Actually, it is the image for the object when there is only one lens.
We use it to calculate the image when there is a second lens. (It is not a real object).