In order to test the ideas in the link below, I would like to get some
sky survey data. I need both galaxies and quasars for the same
SMALL area of sky. I do not want terrabytes of data, something
like a few MB from a selected sky area would most suit. I would
appreciate advice and perhaps a little assistance from any
experienced astronomers in doing this.

http://www.bautforum.com/against-mai...d-quasars.html

In the thread you mention, Ari Jokimaki has already mentioned the SDSS database. I second that recommendation -- I use the SDSS database all the time. It has the information you need.

The most flexible interface is the CasJobs query tool, which permits you to make SQL queries into the latest release. You can, for example, choose to retrieve information about all objects in some small region of the sky which are classified as galaxies or classified as quasars, are within some range of redshifts or magnitudes, and so forth. If you have used SQL before, it won't be hard.

You can use CasJobs by going to

http://casjobs.sdss.org/casjobs/

and registering. Once registered, you can log in and start working. I would recommend that you read through all the tutorial examples first. You'll also need to spend a few hours browsing through the list of all tables in the DR6 database, to figure out the 2 or 3 which are relevant to your work.

I figured it out in about a day. You can, too.

StupendousMan's suggestion is a good one, but if you aren't so familiar with SQL, use the SDSS Search Form here:

http://cas.sdss.org/dr6/en/tools/sea...rm/default.asp

It lets you do more simple queries, and since you want only quasars in a small region of the sky, you shouldn't have problems running into the size limits it imposes.

Let us know if you have any questions!

__________________
"What do you care what other people think?" -- Richard Feynman
"For a successful technology, reality must take precedence over public relations, for nature cannot be fooled." -- Feynman, at the conclusion of his Challenger report

Thank you StupendousMan and Parejkoj.