http://www.rssboard.org/rss-specification 720 http://ecuip-xtf.lib.uchicago.edu/xtf/search?f52-subject%3DActive%20Galactic%20Nuclei Results for your query: f52-subject=Active Galactic Nuclei Thu, 01 Jan 1970 12:00:00 GMT http://ecuip-xtf.lib.uchicago.edu/xtf/view?docId=grxr/apj430279f6_hr/apj430279f6_hr.dc.xml The spectra were shifted to appear as if they were not redshifted before being averaged. All the objects have spectra that look like quasi-stellar objects, but some are of low enough luminosity that the host galaxy is visible and has a name. The main features of the spectrum are as follows: a purple/blue line drawn through the spectrum is the "continuum," mostly due to the AGN, a continuous glow caused by a very hot gas in a strong magnetic field; a red line represents the fitted spectrum of emission lines, thought to arise in a disk that surrounds the central black hole of the AGN. (These are most clear at the right end.) The ions that are seen in emission are labelled: N V, C IV, He II etc. The Roman numeral is the charge of the ion plus one: N V is four-times ionized oxygen, meaning that four electrons have been stripped off the atom. The ion has a net charge of positive four. The black line traces the actual data. Below about 950 Å, neutral hydrogen absorption lines from the intergalactic medium exist in ... http://ecuip-xtf.lib.uchicago.edu/xtf/view?docId=grxr/apj430279f6_hr/apj430279f6_hr.dc.xml Thu, 01 Jan 1970 12:00:00 GMT