High School Spectral Lines: Scrambling & Differentiation

[roineust]

How are different elements spectral lines naturally 'scrambled' and then differentiated by observation, into each and every element contained in a 'single' light beam emanating from a light source? Is the term 'single' correct in this context and if not can you explain why?

 

[sophiecentaur]

How are different elements spectral lines naturally 'scrambled' and then differentiated by observation, into each and every element contained in a 'single' light beam emanating from a light source?

There are two parts to this question. We don't see a light beam. We just see light in a cone which has an angular width which basically depends on the geometry of our telescope system. Within the resolution of a scope an angularly large object appears as a distribution of smaller pixels. Light from each part of, say, a nebula or distant galaxy will vary across the different features. (That's the image we see)

So we look at light from one direction and pass it through a spectrometer. It the star / source is not too far away then all the spectral line components we see are 'expected' because the same elements are emitting (or very often we see absorption lines because the light from a hot object with a continuous spectrum has passed through a region which is relatively cold and low density.

There may be a lot of lines at different 'amplitudes'. Not many amateurs have actually gone to the trouble, these days, to identify the various 'series' from the measurements and it used to be done by hand with a magnifying glass, looking at a photographic plate. It was very hard work, I'm sure, but very do-able for someone with loads of time. Computers can do the job very quickly and reliably.

They can also recognise Patterns, even when Red shift has moved the wavelengths away from their original values. Hubble employed hundreds (at least dozens) of young women over many years to measure the shifts of all the spectra. General principle about Astronomy is that there's a lot of sweat involved even these days, using computers. The software is readily available. Fancy a go?

 

[roineust]

The software is readily available.

Thanks, yes, can you tell me where to download that software?

 

[sophiecentaur]

Thanks, yes, can you tell me where to download that software?

You need to Google with terms like Astrospectroscopy. I know the information is out there because I have a friend who got into the topic and now does it with his own equipment. But you need more than just the software, don't you? What would you do with it if you didn't know the basics. I would go more general, with terms like chemical analysis by spectroscopy.
From your post, it seems to me that you are fairly fresh at the subject so you have to start at the beginning if you really want to make progress. (Most spectrometers are used to look at terrestrially produced light.)

 

[jedishrfu]

Here's the ESO site with info on spectroscopy:

https://www.eso.org/public/teles-instr/technology/spectroscopy/

and here's another with more detailed info:

https://www.atnf.csiro.au/outreach/education/senior/astrophysics/spectrographs.html

and other reference sites with software...

https://www.atnf.csiro.au/outreach//education/senior/astrophysics/spectroscopy_links.html