Survey of faint compact objects

The sample is a random subset of all compact sources with 22.5<=b_j_<=23.5 in three high-latitude fields. Additional data on compact sources with 21<=b_j_<=22.5 have been selected from the higher resolution (13A) survey previously published by Colless et al. (1990), and a subset of these brighter objects has been studied at both dispersions.

Table 1: Summary of the photographic photometry. ------------------------------------------------------------------------ Field Band AAT Seeing Isophote Survey range plates arcsec mag/arcsec2 mag ------------------------------------------------------------------------ 10hr bj J1834 1.7 26.44 20.98<bJ<23.48 rF F1835 1.8 24.61 U U2206 2.0 25.09 13hr bj J1836 1.8 26.52 20.94<bJ<23.44 rF F1837 2.3 24.82 (20.00<bJ<23.60 in zone 13.1) U U2208 2.3 24.88 ------------------------------------------------------------------------ Table 2: The survey observations ------------------------------------------------------------------------ Survey alpha delta Obsvn Detector Exposure Area zone (1950) dates time(s) deg2 ------------------------------------------------------------------------ 10.2 10 43 55.4 +00 05 33 18/3/88 IPCS 15000 0.0330 10.4 10 43 51.4 -00 06 41 20/3/88 IPCS 13500 0.0330 13.1 13 40 32.0 +00 13 22 1-2/6/86 CCD 14500 0.0078 13.2 13 41 57.3 +00 06 25 18/3/88 IPCS 12000 0.0330 ------------------------------------------------------------------------ Table 5: Total b_j_ surface density ------------------------------------------------------------------------ bj-rF Field 0.25 0.50 0.75 1.00 1.25 1.50 1.75 2.00 2.25 2.50 Total ------------------------------------------------------------------------ a 0 0 0 0 74 89 0 296 612 210 1281 b 44 0 105 317 270 224 91 357 702 241 2351 c 0 92 188 278 49 188 98 379 572 196 2040 d 46 190 382 564 147 188 147 379 572 196 2811 ------------------------------------------------------------------------ Table7: Colour distribution of unknown compact sources ------------------------------------------------------------------------ Numbers (deg-2) b_j_-r_F_ 21<=b_j_<=22.5 22.5<=b_J_<=23.5 ------------------------------------------------------------------------ <0.25 - - 0.25-0.50 71 19 0.50-0.75 82 56 0.75-1.00 94 150 1.00-1.25 82 224 1.25-1.50 118 37 1.50-1.75 - 56 1.75-2.00 - 56 2.00-2.25 35 56 2.25-2.50 - 56 2.50-2.75 - 38 2.75-3.00 - 19 >3.00 - - No colour 71 94 Total unknown 552 804 Total compact 1333 1560 All objects 5620 10427 ------------------------------------------------------------------------