Question
Hi Ronald,
About a month ago I installed 1000 sq ft of bluegrass in my backyard here in NJ. I used a sod cutter and stripped the old stuff down to soil, and then laid the sod. What I forgot to do was Aerate or rototill the old soil although I did put down some starter fertilizer. The Sod appears to be fine and looks good except when I look straight down at it, I can see yellow blades closer to the soil surface. Maybe it is still adjusting to the new yard, but my question is if the lawn will be fine for now even though the soil is compacted underneath? Is there a way to gently aerate it now(like a thin spade shovel) without damaging the new sod? I understand I will have to wait at least 6 months or more to use a power Aerator or else risk hurting the new sod. I do have irrigation underground, but I'm afraid the hot days of summer might be too much for roots that are struggling to go deep.

Answer
You did not do anything wrong or bad.
Imagine that you could examine the soil profile after you had removed the existing sod. You would see (cut)roots and root channels of previous roots. And if roots have been there before, they will go there again. Besides, some commercial operators come in, scalp the existing area and lay the sod immediately. They leave a 'care sheet' with the homeowner and that is it.
I have seen many lawns rejuvenated in this way. There have been spectacular failures also. Here are some considerations.
When sod is cut at the sod farm, a high percentage of the roots are cut - separated from the root tip. Those roots will die. Inside the cut sod, there is a flurry of activity.
Almost all the plant resources are thrown into the formation of new roots! Our task is to keep the plant processes going until the roots are strong enough to drill into the new soil surface - whatever or wherever that may be.  
The sod retailer's chief interest is getting the pallet(s) of sod delivered to the customer; or else (s)he has the responsibility for maintaining viability. The customer takes it from there. It is not difficult; but it does require some skillful management.
Keep the newly laid sod moist enough to promote root growth but dry enough to discourage fungus growth. Maybe two short periods of irrigation twice a day; the second done early enough so that the grass blades are dry before the sun goes down.
Examine the turf daily. Look for yellowing along the edges of the sod pieces. If present, it indicates that the pieces were not jammed together tightly. You can fill the gaps with sand. Yellowing in patches indicate too little or too much water. High or low spots; problem with the distribution of water. Most manufacturers provide instructions to increase / decrease the output of the individual sprinkler. Choosing the next (up or down) nozzle size usually does the trick.
Pull upward gently! on the sod at random to find out if and how much rooting is taking place.
As rooting increases , so must watering decrease.
After the first mowing, the lawn can be put on a program of care.
Hope this has helped.