# DSO carthesian coordinate estimations

I'm more in the CS based stack exchange, but this question prompted me to come in here.

I've been compiling a large set of ephemerides for solar system, stars with mag > 6.8, exo planets etc, and I am now working on the DSO catalog.

The app actually holds celestial objects in 3D space, and I made conversions from RA/DEC/dist(parsec) for various objects, but I am having trouble with DSO objects.

I know of a red shift time base formula, but heard the conversion is not very good. Also, I understand that most estimations cannot be counted as precise, but I would like to have these objects within 3D space.

Can anyone tell me what features I should look for in a catalog and what formula I can base myself on for this conversion, if any?

thanks

To calculate any of the measures, you need the object's redshift $$z$$. You will probably need to store the comoving distance (= proper distance today) and redshift so that you can convert to other distance measures quickly without redoing the integral.
• You can get any of the distance measures from the redshift and an assumed cosmology (which tells you the parameters Omega). On the linked page, you find the function $E(z)$, which you will need to integrate to get the comoving distance. The other distance measures can then be computed from that and the redshift.