ASTR-1010 Lecture 9: ASTR 1010 Lecture 9: Lecture 9: The Doppler Effect
19 Feb 2017
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Away from you positive velocity red shift. We can measure the doppler shift of emission or absorption lines in a spectrum. We can then calculate the velocity of the object in the direction either toward or away from earth (radial velocity): red shift: positive wavelength shift: positive velocity. Measure the velocity toward the shift or away from the shift. Q: if a distant galaxy has a substantial redshift (as viewed from our galaxy), then anyone living in that galaxy would see a substantial redshift in a spectrum of the milky way galaxy. A: yes, and the redshifts would be the same. The electromagnetic spectrum: color, wavelength, frequency, energy. All four properties are highly connected: visible light 9roygbiv) is only part (gamma to radio) Theory of quantum mechanics: electrons in atoms can have only certain, specific energies. Each element has a different set of such allowed energy levels. Kir(cid:272)hoff"s la(cid:449)s: co(cid:374)ti(cid:374)uous spe(cid:272)tru(cid:373), e(cid:373)issio(cid:374) li(cid:374)es, a(cid:271)sorptio(cid:374) li(cid:374)es: temperature, composition, velocity.
