STARS WITH ZERO PRPER MOTION AND THE NUMBER OF FAINT QSOS.
暂无分享,去创建一个
The field of SA 57 is surveyed for faint QSOs by studying the properties of stars which lack detectable proper motion. In principle, the method is capable of avoiding selection effects intrinsic to other search techniques. The zero-proper-motion criterion is generally successful, but all of the QSOs that have been studied would have been found with some other conventional technique, so that evidently no significant population of stellar-appearing extragalactic objects has remained undiscovered. After combining the results of several techniques, a surface density of QSOs is obtained which supersedes, but is completely consistent with, the previous point on the log N-m diagram at B = 21.4.
[1] H. Abt,et al. Revised MK spectral atlas for stars earlier than the sun , 1981 .