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1. Red shift question
The galaxy NGC 7320C has a red shift value of z = 0.02.
At what wavelength would you expect to find the hydrogen alpha line in the spectrum of light

How would you solve this question?
Attached Files
2. universe.doc (43.0 KB, 45 views)
3. Last edited by osake; 17-06-2012 at 17:14.
4. Re: Red shift question
(Original post by osake)
The galaxy NGC 7320C has a red shift value of z = 0.02.
At what wavelength would you expect to find the hydrogen alpha line in the spectrum of light

How would you solve this question?
Are you not given a laboratory value for the hydrogen alpha line or are you expected to know it. Anyway you need to use the formula z=-delta lambda/lambda.
5. Re: Red shift question
(Original post by Augmented hippo)
Are you not given a laboratory value for the hydrogen alpha line or are you expected to know it. Anyway you need to use the formula z=-delta lambda/lambda.
No, I am not given a laboratory value.
6. (Original post by osake)
No, I am not given a laboratory value.
In that case it seems that your answer should be 0.02lambda + lambda .....
For the observed wavelength.

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Last edited by xiyangliu; 17-06-2012 at 14:21.
7. Re: Red shift question
(Original post by xiyangliu)
In that case it seems that your answer should be 0.02lambda + lambda .....
For the observed wavelength.

This was posted from The Student Room's iPhone/iPad App
In the mark scheme it says the answer is 669.411 nm, how did they obtain this value?
8. Re: Red shift question
Does it not give you anything else? Such as the temperature of the star?
9. Re: Red shift question
(Original post by osake)
The galaxy NGC 7320C has a red shift value of z = 0.02.
At what wavelength would you expect to find the hydrogen alpha line in the spectrum of light

How would you solve this question?
You need more details to answer this - what other values has the question given you?
10. Re: Red shift question
(Original post by EllaBella<3)
You need more details to answer this - what other values has the question given you?
I have edited my original post and attached the question, they didn't give any other details.
11. Re: Red shift question
(Original post by osake)
I have edited my original post and attached the question, they didn't give any other details.
God I haven't got a clue Is this A2?!

The only way I could think is z=v/c - find v then use v=f(lambda) - don't know how to get the frequency though Sorry, haven't been any help!
12. [QUOTE=EllaBella
Hm... I dnt think v = f(lambda) is necessary since v is the speed of the moving object

Are u given the distance between earth and that galaxy ??

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13. Re: Red shift question
[QUOTE=xiyangliu;38173203][QUOTE=EllaBella
Hm... I dnt think v = f(lambda) is necessary since v is the speed of the moving object

Are u given the distance between earth and that galaxy ??

This was posted from The Student Room's iPhone/iPad App[/QUOTE]

I know. You aren't given any details. The question has been attached anyway.
14. Re: Red shift question
Came here to comment on the book of the same name by Alan Garner. *scurries away quickly*