Figure 20

Figure 20

z=4.11 quasar, 0000-26. At redshift z=1.434 narrow FeII and MgII are seen, with simple velocity structure. From the 6 km/s data the line widths are very similar and the temperature is unknown, but less than about 20,000K. A simulation of FeII 2600 and MgII 2803 at T=15,000K at R=120,000 and S/N 50 per resolution element shows a clear difference between the MgII (lower) and FeII (upper, offset by 0.4 units vertically) line widths (see figure). Some of this is due to the MgII beginning to saturate, but the dominant effect is the different widths because of the different atomic masses. A fit to the simulation gives a maximum turbulent velocity of less than 0.4 km/s, and a temperature error of less than 500K. Data provided by Lu and Sargent (1996).