SDSS DR1 Quasar catalog

Post #1by **selden** » 15.02.2004, 21:35

I've created a Celestia Deep Space Catalog from the Sloan Digital Sky Survey, Data Release 1, Quasar catalog. It includes the locations of 16713 QSOs.

(this links to a much larger picture where you actually can see the dots.)

See http://www.lns.cornell.edu/~seb/celestia/catalogs.html#3.5.6

The SDSS catalog was downloaded from Vizier:
J/AJ/126/2579 SDSS quasar catalog. II. First data release (Schneider+, 2003)

Unfortunately, because of the large number of objects, this Addon causes Celestia to run frustratingly sloooowly....

Added the following week:

If you have Celestia v1.3.2pre3 or later, get the CMOD version of this database instead. It's fast.

Buzz · Post #2by **Buzz** » 16.02.2004, 18:10

Great Selden, I like things like this! I am quite curious how it will run on my system.

Buzz · Post #3by **Buzz** » 17.02.2004, 22:14

Well, performance is better than I feared, even on my old 1GHz pc. Zooming in and out is slow indeed, but rotations are a bit smoother; this shows the 3D structure very nicely. So: thanks Selden!

Post #4by **selden** » 17.02.2004, 22:50

Well, of course, the large scale structure just shows you the areas that the SDSS has covered in the sky. It's the fine scale structure that I wanted to be able to see -- the "great walls" and voids, for example.

Cham · Post #5by **Cham** » 18.02.2004, 01:01

This may be great. Can you actually see the large scale structures in Celestia ?

I tried your file. It was smoother than I expected, too, but I didn't noticed any structures at the largest scale.

Post #6by **selden** » 18.02.2004, 11:22

Cham,

By "large scale structure" I meant the fan-like shapes of the regions filled by the dots.

If you look at them from the solar system, you see the regions "end-on." That shows the RA and Dec of the areas on the sky that the SDSS has included in their first data release. If you look at them from "outside" -- distances beyond about 35GLY -- you can see them spreading out from the center like fans or wings.

Apparently the database that shows the "walls" and "voids" best is the 2df catalog of about 100,000 objects. They looked at 4 different regions, so I'll try doing that one next as separate catalogs, probably this next weekend.