ASTR 1102 Study Guide - Grote Reber, Quasar, Active Galactic Nucleus
Document Summary
Quasars were first discovered in the mid-1900s by grote reber, who built the first true radio telescope. Examining the spectra of quasars revealed that they are immensely distant. Quasars have bright emission lines that are red shifted, whereas ordinary galaxies have absorption lines in its spectrum: explain why astronomers cannot use any of the standard candles described in section. The spectrum of a quasar has emission lines instead of absorption lines. Because they have excited hydrogen atoms which emit radiation: it was suggested in the 1960s that quasars might be compact objects ejected at high speeds from the centers of nearby ordinary galaxies. Explain why the absence of blue shifted quasars disproves this hypothesis. Halton c. arp suggested that the hubble law did not apply to quasars. If part of a quasar"s redshift was caused by some not yet discovered phenomenon, then the quasar could be much closer to earth than the hubble law wouls have us believe.
