EMISSION LINES
The Data
There are several other quasars which belong to the same spectral class
(Varshni, 1976)
as 0237-233. We summarize the available data on emission lines for all these quasars
in
Table I.
There are a number of other quasars
(Hewitt and Burbidge, 1987)
which appear to belong to this spectral group but the available data are too poor to make a
definite assignment. For each quasar the first row shows the reported wavelengths.
Below each wavelength, where known, are shown the characteristics of that line. For
three of these quasars, 0237-233, 0029+003, and 1448-232 the available emission
line data appear to be better than those for the rest.
0237-233.
There are only two sets of measurements of the emission lines, one due to
Arp et al. (1967)
and the other due to
Burbidge (1967).
Arp et al. (1967)
obtained the spectra (for emission lines) at a dispersion of 600 Å per mm at the prime-focus of the Lick
120-inch telescope. These authors found five emission lines.
Burbidge (1967)
also used the Lick 120-inch telescope and the spectrum was obtained at a dispersion of
370 Å per mm on baked IIaO emulsion. She found two emission lines. There are large
differences in the wavelengths of these two lines as given by
Arp et al. (1967)
and by
Burbidge (1967).
0029+003.
This quasar is one of a close pair of quasars. The other member is 0028+003;
the separation between the two is 62 arcseconds.
Shaver et al. (1982)
observed the two quasars at low (114 Å per mm) and intermediate (59 Å per mm) dispersion with the
European Southern Observatory 3.6 m telescope, and at high dispersion (33 Å per mm)
with the Anglo-Australian telescope in October 1981. The line at 3920 Å is absent. For
other quasars in
Table I,
in the redshift hypothesis, this line has been identified with Lyman alpha.
Its absence in 0029+003 shows that such redshifts which primarily depend on a line
being identified as Lyman alpha are highly suspect.
1448-232.
The best data appear to be that of Chen et al. (1983,
1984).
Their observations were carried out in 1977, 1979, and 1980 at a dispersion of about
33 Å mm per 1 with the Anglo-Australian telescope.
Next Section: Emission Lines, Identification