### 9. THE QSO PAIR Q2343+1229, Q2344+1225

This pair was discovered on a U.K. Schmidt objective prism plate by C. Hazard
and confirmed by Boksenberg and myself. Q2344+1229 has a magnitude of 17 and
a redshift of *z* = 2.53, while Q2344+1225 has magnitude of 17.5
and a redshift of
*z* = 2.77. There is a common absorption system in both objects at
*z*_{abs} = 2.42; in
Q2344+1229 this system has a damped
Ly- absorption line, while in
Q2344+1225
the system is weaker and more complex. To add to the coincidences, there
is a damped
Ly- absorption in the higher
redshift QSO, Q2344+1225, at
*z*_{abs} = 2.53, similar to
that of the lower redshift object. The separation of these two QSOs is
5.7 arcmin,
corresponding to 2 - 4 Mpc at *z* = 2.5, depending on the
cosmological model. This
is yet another case of a pair of common or associated absorption in
relatively widely
spaced QSOs. It will be interesting to explore the limits on the
physical properties of
the object responsible for the damped
Ly- system in Q2344+1225 which
are imposed
by its proximity to Q2344+1229. Interestingly, there is a third, fainter
QSO about
2 arcmin from Q2344+1225 with a similar emission redshift, *z* =
2.75, but with no common absorption systems.