<p>We have data for a globular cluster M13. We have plotted the radius in pixels against the surface brightness in magnitudes per square arcsec.</p>
<p>We have to find the king model for this. We don't exactly know how to do that. We think we just have to set the units to solar luminosities and then plot it again, but if that is the case we don't really know what our graph tells us that the first graph did not tell us. So we think we are doing that wrong. If we are actually doing it right we don't know what this tells us. Can somebody help?</p>

CC BY-SA 4.0
2021-07-20T21:37:20.323Z
This is written in the first person plural ...  "We have...", "We think"...  Who are you collaborating with?   What is your group's position, are you students? postgrads? A team with a PI?  Are you the PI?
James K
CC BY-SA 4.0
2021-07-21T10:12:16.007Z
Probably the starting point for research http://articles.adsabs.harvard.edu/pdf/1966AJ.....71...64K
James K
CC BY-SA 4.0
2021-07-21T13:23:45.150Z
A much better starting point is [King 1962](https://ui.adsabs.harvard.edu/abs/1962AJ.....67..471K/abstract); the definition of the “King profile” is in Eqn. 14 of that paper.
Peter Erwin
<globular-clusters>
How do we find the king model of a globular cluster?
Danielvanheuven
# How do we find the king model of a globular cluster?

(Asked by: username_0 on 2019-06-03)

We have data for a globular cluster M13. We have plotted the radius in pixels against the surface brightness in magnitudes per square arcsec.

We have to find the king model for this. We don't exactly know how to do that. We think we just have to set the units to solar luminosities and then plot it again, but if that is the case we don't really know what our graph tells us that the first graph did not tell us. So we think we are doing that wrong. If we are actually doing it right we don't know what this tells us. Can somebody help?

**Tags:** globular-clusters
> **Comments:**
> **username_1**: This is written in the first person plural ...  "We have...", "We think"...  Who are you collaborating with?   What is your group's position, are you students? postgrads? A team with a PI?  Are you the PI?  
> **username_1**: Probably the starting point for research http://articles.adsabs.harvard.edu/pdf/1966AJ.....71...64K  
> **username_2**: A much better starting point is [King 1962](https://ui.adsabs.harvard.edu/abs/1962AJ.....67..471K/abstract); the definition of the “King profile” is in Eqn. 14 of that paper.  

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## 0 answers

