<p>I have R (kpc)- distance from galactic center and v(km/s) rotational speed at that distance. I was thinking of creating a simple model comprising of 3 terms 1 for Keplerian component another for rigid body and 3rd constant, V(model)= (a/sqrt(r)) + bwr + c , where a,b,c are constants , and 'w' I am not sure how to get from this data. I also plan on using Excel's Solver feature later to minimize V(obs) - V(model). I also intend on doing all this modelling in excel instead of python or any other programming language (since I'm not very comfortable with them)
<a href="https://i.sstatic.net/fpOxF.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/fpOxF.png" alt="Data that I was plotting and a preliminary model" /></a></p>

CC BY-SA 4.0
2022-05-03T06:46:29.950Z
What exactly is your question? Besides that, Excel seems like the worst possible choice and I'd like to encourage you to step out of your comfort zone and learn to use real tools for data analysis.
planetmaker
CC BY-SA 4.0
2022-05-09T21:33:36.020Z
There are tools in python which can help you to find these constants. Such as  numpy.polyfit
seVenVo1d
<galaxy><rotation><modeling>
How to model galactic rotation curves?
Hardek A.
# How to model galactic rotation curves?

(Asked by: username_0 on 2022-05-03)

I have R (kpc)- distance from galactic center and v(km/s) rotational speed at that distance. I was thinking of creating a simple model comprising of 3 terms 1 for Keplerian component another for rigid body and 3rd constant, V(model)= (a/sqrt(r)) + bwr + c , where a,b,c are constants , and 'w' I am not sure how to get from this data. I also plan on using Excel's Solver feature later to minimize V(obs) - V(model). I also intend on doing all this modelling in excel instead of python or any other programming language (since I'm not very comfortable with them)
[![Data that I was plotting and a preliminary model](https://i.sstatic.net/fpOxF.png)](https://i.sstatic.net/fpOxF.png)

**Tags:** galaxy, rotation, modeling
> **Comments:**
> **username_1**: What exactly is your question? Besides that, Excel seems like the worst possible choice and I'd like to encourage you to step out of your comfort zone and learn to use real tools for data analysis.  
> **username_2**: There are tools in python which can help you to find these constants. Such as  numpy.polyfit  

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## 0 answers

