Spectra of Matter in ASTR 105G: The Planets - Prof. Jason Jackiewicz, Study notes of Astronomy

Download Spectra of Matter in ASTR 105G: The Planets - Prof. Jason Jackiewicz and more Study notes Astronomy in PDF only on Docsity! Lecture 12 Spectra of Matter ASTR 105G: The Planets February 24, 2009 Announcements 1. Exam Thursday 2. Review session tomorrow night 7pm here 3. Some homework problems from HW5 Last time ... • We talked about what light can do when it interacts with matter: 4 possibilities • The building blocks of matter: nuclei, electrons, atoms, molecules • Phase changes • We began discussing energy levels of atoms Quantitative View of Energy Levels of Hydrogen Source of Figure 1: http://web.njit.edu/ gary/728/Lecture2.html 1 Radiation and Matter 1.1 Interpretation of Astronomical Radiation and Spectra Spectroscopy • Spectroscopy studies the intensity of light (number of photons or energy) at different wave- lengths. These are “light curves”, or “spectra” • There are generally 3 types of spectra: 1. Continuous: Broad spread of intensity over all wavelengths 2. Emission: Discrete peaks in intensity where electrons are jumping into lower atomic energy levels 3. Absorption: Discrete dips in intensity where atoms have absorbed radiation at certain energy levels and jumped to higher levels The Solar Spectrum Source of Figure 2: http://www.windowtinting.com.au/prestige-spectral-facts.asp Lecture 12 February 24, 2009 2 / 5 Figure 1: Energy levels of the hydrogen atom.