<p>First of all, I know spectral index is <span class="math-container">$\alpha=\frac{log\frac{S_1}{S_2}}{log\frac{v_1}{v_2}}$</span> where <span class="math-container">$s$</span> are the flux densities and <span class="math-container">$v$</span> is the frequencies. I wonder that If i can use spectral index and an flux density observation to calculate other? Basically i know that the spectrum follows power law spectrum where I want to make this calculation (GHz radio frequencies), it almost fits the power law.</p>

CC BY-SA 4.0
2023-11-22T13:22:12.933Z
If it fits almost a power law, you can almost apply that power law to get the flux at different frequencies. Do it, but be aware and discuss the uncertainties and limitations. You can do anything, if you have good enough justification. (NB: For that reason, the oral examp of a PhD often is called "defence": You defend and justify and have to convice others of proper scrutiny and correct application of knowledge of the methods of what you have been doing :) )
planetmaker
CC BY-SA 4.0
2023-11-23T02:29:31.640Z
Can you put an appropriate title that reflects the body of the post? We know you have questions on this topic.
Nilay Ghosh
<radio><flux>
How to calculate flux at a specific frequency from another frequency and spectral index
Ege Tunç
# How to calculate flux at a specific frequency from another frequency and spectral index

(Asked by: username_0 on 2023-11-22)

First of all, I know spectral index is $\alpha=\frac{log\frac{S\_1}{S\_2}}{log\frac{v\_1}{v\_2}}$ where $s$ are the flux densities and $v$ is the frequencies. I wonder that If i can use spectral index and an flux density observation to calculate other? Basically i know that the spectrum follows power law spectrum where I want to make this calculation (GHz radio frequencies), it almost fits the power law.

**Tags:** radio, flux
> **Comments:**
> **username_1**: If it fits almost a power law, you can almost apply that power law to get the flux at different frequencies. Do it, but be aware and discuss the uncertainties and limitations. You can do anything, if you have good enough justification. (NB: For that reason, the oral examp of a PhD often is called "defence": You defend and justify and have to convice others of proper scrutiny and correct application of knowledge of the methods of what you have been doing :) )  
> **username_2**: Can you put an appropriate title that reflects the body of the post? We know you have questions on this topic.  

---

## 0 answers

