About Spectroscopy
Spectroscopy is a complex art, but it is very useful in helping scientists understand how an object like a black hole, neutron star, or active galaxy is producing light, how fast it is moving, and even what elements it is made of. A spectrum is simply a chart or a graph that shows the intensity of light being emitted over a range of eneriges. Spectra can be produced for any energy of light from low-energy radio waves to very high-energy gamma rays.
Spectra are complex because each spectrum holds a wide variety of information. For instance, there are many different mechanisms by which an object, like a star, can produce light – or using the technical term for light, electromagnetic radiation. Each of these mechanisms has a characteristic spectrum.
The pages in this section go into further detail about what spectroscopy is, what processes produce characteristic spectra, and how astronomers use spectra to learn about astronomical objects.
- A quick look at a spectrum
- Take a brief look at a supernova remnant spectrum to see what a typical spectrum plot looks like.
- The electromagnetic spectrum
- Any discussion of the spectrum of light must start with the electromagnetic spectrum - the full spectrum of light.
- Understanding Atoms
- One important feature of spectra are emission lines, but to understand where they come from, it's important to know a thing or two about atoms.
- Line Emission
- Atoms emit light at identifiable energies, which makes the spectrum of an atom just like a fingerprint. This section talks about how these emission lines are produced and how to identify an atom from a spectrum of lines.
- Continuum Emission
- In addition to emitting discrete features, light can be emitted in a continuum, much like a rainbow where you see all colors of the visible spectrum. This section discusses some of the mechanisms that produce X-ray continuum emission.
- Putting it all together: spectra and astronomy
- How do astronomers get information out of spectra from astronomical objects? This section revisits the supernova remnant spectrum and looks at the different parts as an astronomer would see them.
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