Volvo: Loud hum from engine-follow up, vacuum line, volvo 850

Question

my loud volvo   QUESTION: I have a 1997 volvo 850.  While I am not giving it any gas, a loud, rather whiny hum erupts from the right side of the engine.  It is the loudest while idle, and lowers in pitch when I give it gas.  It is not noticeable on the highway.  

I've attached a photo of where the noise appears to be coming from (to my best ability)

Please, please help me.  It is so embarrassing.

ANSWER: Preston,
Remove the drive belt and run the engine. That will elimanate the P/S pump, Alt, A/C comp and belt tensioner idler pulleys. If the noise is still there then look behind the timing cover. Some 850's have a vacuum line at the front of the intake manifold look at that. Otherwise there are not any moving parts in the area you are pointing to.

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QUESTION: Thanks for responding so quick.  I'm assuming once I take that belt off, I can't simply drive it like that?  And if that answer is no, but removing the belt stops the noise...I have no idea what to replace.  I'm sorry I'm such a car noobie.

Answer
Preston,
NO DO NOT drive the car. The drive belt is off. P/S A/C Alt will not be working. You only remove the belt to simply see if the noise would stop. Then you need further testing. Maybe spin by hand the pulleys so you can see if one of those feel tight and or make noise. Seek help if your not sure.