<p>I am estimating the internal extinction of a spiral-barred galaxy (rest frame extinction). I use UV images to study the galaxy. I have Balmer decrement values of individual knots using which, I estimate the c(H beta) and thus calculate the internal extinction. I also have a MIPS 24 micron image to calculate the internal extinction values.</p>
<p>However, a particular region of the galaxy, say A, is not covered by MIPS but in the Balmer decrement map. To add to my woes, the Balmer decrement map doesn't cover another region, say B, but is covered by the MIPS map. I do not have any other data. Can I use the extinction values calculated using IR data in region B and values calculated using Balmer decrement in region A?</p>

CC BY-SA 4.0
2022-07-18T12:23:12.900Z
You can do many things. You just have to make sufficient reason. Best show the correlation and derive a correction factor from other places where both data are available and can be assessed (possibly from within our own milkyway)
planetmaker
CC BY-SA 4.0
2022-07-19T05:07:44.983Z
Has someone carried out similar work wherein internal extinction was calculated using multiple methods for different regions of the same galaxy? I believe there exists a correlation between corrected magnitudes using both  methods.
SlightDecoy
<galaxy><extinction>
Internal extinction calculation
SlightDecoy
# Internal extinction calculation

(Asked by: username_0 on 2022-07-18)

I am estimating the internal extinction of a spiral-barred galaxy (rest frame extinction). I use UV images to study the galaxy. I have Balmer decrement values of individual knots using which, I estimate the c(H beta) and thus calculate the internal extinction. I also have a MIPS 24 micron image to calculate the internal extinction values.

However, a particular region of the galaxy, say A, is not covered by MIPS but in the Balmer decrement map. To add to my woes, the Balmer decrement map doesn't cover another region, say B, but is covered by the MIPS map. I do not have any other data. Can I use the extinction values calculated using IR data in region B and values calculated using Balmer decrement in region A?

**Tags:** galaxy, extinction
> **Comments:**
> **username_1**: You can do many things. You just have to make sufficient reason. Best show the correlation and derive a correction factor from other places where both data are available and can be assessed (possibly from within our own milkyway)  
> **username_0**: Has someone carried out similar work wherein internal extinction was calculated using multiple methods for different regions of the same galaxy? I believe there exists a correlation between corrected magnitudes using both  methods.  

---

## 0 answers

