<p>From <a href="https://books.google.de/books?id=tQswBQAAQBAJ&amp;pg=PA465&amp;lpg=PA465&amp;dq=core-to-star%20efficiency&amp;source=bl&amp;ots=JJOAAWFbxm&amp;sig=dJQw-o9QGl8sH36DdeQe0kkRmkY&amp;hl=it&amp;sa=X&amp;ei=gUNbVYumKISasAHk4IHwCg&amp;ved=0CCIQ6AEwAA#v=onepage&amp;q=core-to-star%20efficiency&amp;f=false" rel="nofollow">this book</a> it seems you can have $\epsilon_{core}$ values raging from ~$30\%$ (a low value) up to $70\%$ (which is more "usual", i.e., requested by theories).</p>

<p>More information can be found <a href="http://iopscience.iop.org/0004-637X/545/1/364/pdf/51522.web.pdf" rel="nofollow">here</a> and <a href="http://iopscience.iop.org/0004-637X/761/2/156/pdf/apj_761_2_156.pdf" rel="nofollow">here</a>.</p>

CC BY-SA 3.0
2015-05-19T14:16:29.147Z
2015-05-19T14:16:29.147Z
Py-ser
<p>I was reading <a href="http://www.sciencemag.org/content/344/6180/183.full.pdf" rel="nofollow"><em>Unfolding the Laws of Star Formation: The Density Distribution of Molecular Clouds</em></a> by Kainulainen et al., which discusses star formation rates and efficiencies.</p>

<p>One variable used is $\varepsilon_{\text{core}}$, the core-to-star efficiency, describing how much gas above the critical value of $s$, the logarithmic mean-normalized density, forms a star.</p>

<p>I'm using this parameter in some calculations, but I'd like to use an average value, as opposed to a value for a given molecular cloud.</p>

<p>What is a typical value for $\varepsilon_{\text{core}}$?</p>

<star-formation><gas>
What is a typical value for core-to-star efficiency?
HDE 226868
# What is a typical value for core-to-star efficiency?

(Asked by: username_0 on 2015-05-17)

I was reading [*Unfolding the Laws of Star Formation: The Density Distribution of Molecular Clouds*](http://www.sciencemag.org/content/344/6180/183.full.pdf) by Kainulainen et al., which discusses star formation rates and efficiencies.

One variable used is $\varepsilon\_{\text{core}}$, the core-to-star efficiency, describing how much gas above the critical value of $s$, the logarithmic mean-normalized density, forms a star.

I'm using this parameter in some calculations, but I'd like to use an average value, as opposed to a value for a given molecular cloud.

What is a typical value for $\varepsilon\_{\text{core}}$?

**Tags:** star-formation, gas

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## 1 answers

### Answer by username_1 on 2015-05-19. Score: 1 | Accepted answer

From [this book](https://books.google.de/books?id=tQswBQAAQBAJ&pg=PA465&lpg=PA465&dq=core-to-star%20efficiency&source=bl&ots=JJOAAWFbxm&sig=dJQw-o9QGl8sH36DdeQe0kkRmkY&hl=it&sa=X&ei=gUNbVYumKISasAHk4IHwCg&ved=0CCIQ6AEwAA#v=onepage&q=core-to-star%20efficiency&f=false) it seems you can have $\epsilon\_{core}$ values raging from ~$30\%$ (a low value) up to $70\%$ (which is more "usual", i.e., requested by theories).

More information can be found [here](http://iopscience.iop.org/0004-637X/545/1/364/pdf/51522.web.pdf) and [here](http://iopscience.iop.org/0004-637X/761/2/156/pdf/apj_761_2_156.pdf).


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