Get-VM to list VM name only

I am using following command to generate text file of all Windows servers that are powered on

Get-Vm where {$_.guest -match 'windows'} | where {$_.PowerState -eq 'PoweredOn'} | Out-File D:\Scripts\SL.txt

This generates list with following information :

Name                 PowerState Num CPUs Memory (MB)

What I really want is to generate list with name ONLY and and omit PowerState Num CPU's Memory.

Yasar