<p>I have the H<span class="math-container">$\alpha$</span> line flux of an AGN and I am trying to calculate the Bolometric luminosity using it. Bolometric luminosity can be calculated from O[III] fluxes by <span class="math-container">$L_{\rm Bol} = 3500 L_{\rm O[III]}$</span>.</p>
<p>What is the <span class="math-container">$\rm O[III]/H\alpha$</span> line flux ratio for AGN?</p>
<p>I am new here, any help or redirection to an appropriate forum is immensely appreciated!</p>

CC BY-SA 4.0
2020-09-10T19:50:09.180Z
Do you have any other quantities given, e.g. the flux for $[NII]$ or $H\beta$? In this case **a variant of the famous BPT diagram** might be what you ar looking for. If not, I am very sceptical whether there is a reliable, tight $[OIII]$/$H\alpha$ ratio for AGN. Anyhow, where do you get the relationship between $L_{bol}$ and the $O[III]$ flux if you do not mind my asking?
Diazenylium
CC BY-SA 4.0
2020-09-11T07:16:33.007Z
Hi, no unfortunately neither $N[II]$ nor $H\beta$ fluxes are available. But thankfully we came across [Stern, J., & Laor, A. (2012)](https://academic.oup.com/mnras/article/426/4/2703/1011509) which helped us getting an estimate of the Bolometric luminosity. Lastly, [Heckman et al.](https://iopscience.iop.org/article/10.1086/422872) derive a bolometric correction of $L_{BOL}/L_{[OIII]} = 3500$.
lordparthurnaax
<galaxy><radio-astronomy><spectrometry><active-galaxy><flux>
What is the O[III]/H$\alpha$ line ratio for Active Galactic Nuclei?
lordparthurnaax
# What is the O[III]/H$\alpha$ line ratio for Active Galactic Nuclei?

(Asked by: username_0 on 2020-09-07)

I have the H$\alpha$ line flux of an AGN and I am trying to calculate the Bolometric luminosity using it. Bolometric luminosity can be calculated from O[III] fluxes by $L\_{\rm Bol} = 3500 L\_{\rm O[III]}$.

What is the $\rm O[III]/H\alpha$ line flux ratio for AGN?

I am new here, any help or redirection to an appropriate forum is immensely appreciated!

**Tags:** galaxy, radio-astronomy, spectrometry, active-galaxy, flux

> **Comments:**
> **username_1**: Do you have any other quantities given, e.g. the flux for $[NII]$ or $H\beta$? In this case **a variant of the famous BPT diagram** might be what you ar looking for. If not, I am very sceptical whether there is a reliable, tight $[OIII]$/$H\alpha$ ratio for AGN. Anyhow, where do you get the relationship between $L_{bol}$ and the $O[III]$ flux if you do not mind my asking?  
> **username_0**: Hi, no unfortunately neither $N[II]$ nor $H\beta$ fluxes are available. But thankfully we came across [Stern, J., & Laor, A. (2012)](https://academic.oup.com/mnras/article/426/4/2703/1011509) which helped us getting an estimate of the Bolometric luminosity. Lastly, [Heckman et al.](https://iopscience.iop.org/article/10.1086/422872) derive a bolometric correction of $L_{BOL}/L_{[OIII]} = 3500$.  

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## 0 answers

