<p>Suppose I have a cosmological simulation with points in xyz space at a certain redshift in a cube like this:</p>
<p><a href="https://i.sstatic.net/PS6Fb.jpg" rel="noreferrer"><img src="https://i.sstatic.net/PS6Fb.jpg" alt="enter image description here" /></a></p>
<p>And I have these for many cubes of different redshifts say from z=0 to z=2. Now I want to generate how that would look to an observer at z=0. In theory, it should look something like this (from SDSS):</p>
<p><a href="https://i.sstatic.net/m6ALW.png" rel="noreferrer"><img src="https://i.sstatic.net/m6ALW.png" alt="enter image description here" /></a></p>
<p>Is there any software that creates mock surveys like this? My goal is not just to have hydrodynamic simulations but rather mock catalogs that are similar to the SDSS survey. I found the following paper: <a href="https://www.giss.nasa.gov/staff/mway/cluster/cole_mnras_300_945.pdf" rel="noreferrer">https://www.giss.nasa.gov/staff/mway/cluster/cole_mnras_300_945.pdf</a> which seems to be mostly what I'm looking for but I can't find any software for this online (it seems this paper was written in the late 90s).</p>
<p>EDIT:
I found the following: <a href="https://nbodykit.readthedocs.io/en/latest/catalogs/mock-data.html" rel="noreferrer">https://nbodykit.readthedocs.io/en/latest/catalogs/mock-data.html</a> and it might be what I’m looking for. I will update if this is the case</p>

CC BY-SA 4.0
2021-02-26T15:12:16.613Z
I thought that *we already were* in a cosmological simulation! ;-)
uhoh
CC BY-SA 4.0
2021-02-27T12:01:36.607Z
You can also ask in a more program oriented SE. Beside cosmological consideration, the task might be similar in other cases/phenomena.
Alchimista
CC BY-SA 4.0
2021-02-27T17:27:21.223Z
Thank you I probably will do this!
kauii8
<cosmology><software><visualization><sloan-dss>
How to place an observer in a cosmological simulation
kauii8
# How to place an observer in a cosmological simulation

(Asked by: username_0 on 2021-02-25)

Suppose I have a cosmological simulation with points in xyz space at a certain redshift in a cube like this:

[![enter image description here](https://i.sstatic.net/PS6Fb.jpg)](https://i.sstatic.net/PS6Fb.jpg)

And I have these for many cubes of different redshifts say from z=0 to z=2. Now I want to generate how that would look to an observer at z=0. In theory, it should look something like this (from SDSS):

[![enter image description here](https://i.sstatic.net/m6ALW.png)](https://i.sstatic.net/m6ALW.png)

Is there any software that creates mock surveys like this? My goal is not just to have hydrodynamic simulations but rather mock catalogs that are similar to the SDSS survey. I found the following paper: <https://www.giss.nasa.gov/staff/mway/cluster/cole_mnras_300_945.pdf> which seems to be mostly what I'm looking for but I can't find any software for this online (it seems this paper was written in the late 90s).

EDIT:
I found the following: <https://nbodykit.readthedocs.io/en/latest/catalogs/mock-data.html> and it might be what I’m looking for. I will update if this is the case

**Tags:** cosmology, software, visualization, sloan-dss

> **Comments:**
> **username_1**: I thought that *we already were* in a cosmological simulation! ;-)  
> **username_2**: You can also ask in a more program oriented SE. Beside cosmological consideration, the task might be similar in other cases/phenomena.  
> **username_0**: Thank you I probably will do this!  

---

## 0 answers

