Physical Quantities measured
What Is Spectroscopy
Nature of light
The Electromagnetic Spectrum
General Types of Spectra
Types of Spectroscopy
How Spectrometer work?
Types of Spectroscopy
Examples of Spectroscopy in Astronomy
Probing the Formation of Stars in Colliding Galaxies in the universe.
Uncovering the mystery of quasar
Spectroscopy in Astronomy camp
Stars like our own Sun
1. Introduction Spectroscopy
Spectroscopy is the study of matter and its properties by investigating light, sound, or particles that are emitted, absorbed or scattered by the matter under ...view middle of the document...
Physical Quantity Measured
The type of spectroscopy depends on the physical quantity measured. Normally, the quantity that is measured is an amount or intensity of something.
The intensity of emitted electromagnetic radiation and the amount of absorbed electromagnetic radiation are studied by electromagnetic spectroscopy (see also cross section).
The amplitude of macroscopic vibrations is studied by acoustic spectroscopy and dynamic mechanical spectroscopy.
Kinetic energy of particles is studied by electron energy loss spectroscopy and Auger electron spectroscopy (see also cross section).
The mass-to-charge ratios of molecules and atoms are studied in mass spectrometry, sometimes called mass spectroscopy. Mass spectrometry is more of a measuring technique (metric) than an observation (scopic) technique but can produce a spectrum of masses, a mass spectrum, similar in appearance to other spectroscopy techniques.
The number of molecules or atoms or quantum-mechanical states to which the frequency or energy parameter applies. In this case the spectrum is usually called cross section.
What is Spectroscopy?
Spectroscopy pertains to the dispersion of an object’s light into its component colors (i.e. energies). By performing this dissection and analysis of an object’s light, astronomers can infer the physical properties of that object (such as temperature, mass, luminosity and composition).
But before we hurtle headlong into the wild and woolly field of spectroscopy, we need to try to answer some seemingly simple questions, such as what is light? And how does it behave? These questions may seem simple to you, but they have presented some of the most difficult conceptual challenges in the long history of physics. It has only been in this century, with the creation of quantum mechanics that we have gained a quantitative understanding of how light and atoms work. You see, the questions we pose are not always easy, but to understand and solve them will unlock a new way of looking at our Universe.
The Nature of Light
To understand the processes in astronomy that generate light, we must realize first that light acts like a wave. Light has particle-like properties too, so it’s actually quite a twisted beast (which is why it took so many years to figure out). But right now, let’s just explore light as a wave.
Picture yourself wading around on an ocean beach for a moment, and watch the many water waves sweeping past you. Waves are disturbances, ripples on the water, and they possess a certain height (amplitude), with a certain number of waves rushing past you every minute (the frequency) and all moving at a characteristic speed across the water (the wave speed). Notice the distance between successive waves? That’s called the wavelength.
Keeping this analogy in mind, let’s leave the ocean beach for a while and think about light like a wave. The wave speed of a light wave is simply the speed of light, and different wavelengths of...