10 Tables

Table 1: APM Background Source Density

APM Source	$\bar{\rho}_{opt}$	$\sigma_{opt}^2$
Properties	($10^{-4}$ arcsec$^{-2}$)	($10^{-8}$ arcsec$^{-4}$)
All matches	7.58	7.10
Stellar on both plates	1.60	0.06
Stellar on at least 1 plate	5.16	3.85
Non-stellar on both plates	0.41	0.13
Non-stellar on at least 1 plate	2.98	3.57
Detected on both plates	2.56	0.51
Detected on only 1 plate	5.02	6.59
Detected only on red plate	2.60	2.76
Detected only on blue plate	2.43	3.83

Table 2: Confidence Radii and False Rates for Various Source Types

APM Sources	FIRST Sources	90% Radiusa	Number of	Number of Chance	Percentage of
		(arcsec)	True Matchesb	Coincidencesc	False Matches
All	All	4.2	65400	13000	16.6%
Non-stellard	All	4.0	22600	640	2.7%
Stellard	All	1.7	7600	520	6.3%
All	Unresolved	2.0	17800	850	4.6%
Non-stellard	Unresolved	2.2	6200	60	0.9%
Stellard	Unresolved	1.1	2300	60	2.4%

(a) APM-FIRST separation that encloses 90% of the true associations.

(b) Estimated number of true matches within the 90% radius.

(c) Estimated number of chance background matches within the 90% radius.

(d) APM classification on both $E$ and $O$ plates.

Table 3: Confidence and Reliability for Single Band Detections

	Blue-only objects		Red-only objects
Radius	Completeness	Reliability	Completeness	Reliability
(arcsec)
1.0	0.56	0.93	0.46	0.98
2.0	0.78	0.82	0.70	0.94
3.0	0.88	0.71	0.78	0.89
4.0	0.94	0.60	0.84	0.83
5.0	0.97	0.50	0.87	0.77

Table 4: Sample Page from FIRST-APM Source Catalog

RA	Dec	$\Delta$RA	$\Delta$Dec	Sep	Ecl	Epsf	E	Ocl	Opsf	O	O-E	Plate	$S_p$	$S_i$	Maj	Min	PA
(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)	(10)	(11)	(12)	(13)	(14)	(15)	(16)	(17)	(18)
08 00 00.099	+32 06 09.80	-1.86	-0.23	1.87	1	2.49	20.72	-1	-0.31	21.88	1.16	1344	1.10	1.09	3.0	-2.7	173.9
08 00 00.234	+43 45 30.57	-0.56	-0.21	0.59	-1	-0.07	20.22	0	0.00	-22.17	-9.99	1329	8.52	9.27	2.1	1.0	105.7
08 00 00.243	+22 26 24.80	0.56	0.38	0.67	1	5.09	19.77	0	0.00	-21.85	-9.99	226	1.21	1.05	1.5	-3.0	179.1
08 00 00.397	+44 39 14.16	2.00	0.17	2.00	0	0.00	-20.76	-1	0.24	21.31	-9.99	1317	19.48	22.0	2.3	1.5	80.0
08 00 00.752	+32 46 50.87	0.14	-0.77	0.78	1	4.60	19.54	2	3.11	22.46	2.91	989	4.20	3.90	-1.1	-1.7	67.1
08 00 01.358	+47 01 38.37	-0.16	-0.16	0.23	0	0.00	-20.76	-1	0.97	22.23	-9.99	1317	2.68	3.12	2.2	2.2	90.3
08 00 02.263	+51 36 09.10	-0.31	0.30	0.43	1	13.85	12.08	2	47.05	15.00	2.92	985	1.49	1.75	4.2	-2.0	36.6
08 00 02.302	+31 17 20.98	2.27	1.38	2.65	-1	-0.11	20.48	1	2.85	22.21	1.73	1344	2.16	2.73	3.3	2.1	169.9
08 00 02.515	+35 49 27.12	-2.02	4.07	4.54	-1	-1.52	18.88	-1	-0.96	21.40	2.52	989	1.09	0.87	2.2	-3.6	132.4
08 00 02.702	+22 48 54.11	-0.79	-0.66	1.03	2	24.52	17.29	1	3.15	21.62	4.33	226	1.87	2.91	5.3	2.6	94.6
08 00 02.932	+27 17 27.51	-0.64	0.46	0.79	-1	0.80	20.48	-1	0.40	20.77	0.29	1344	5.37	5.56	1.3	0.6	0.4
08 00 03.250	+36 29 42.11	0.46	0.14	0.48	1	3.68	19.67	0	0.00	-22.18	-9.99	989	46.71	58.72	3.7	1.5	21.6
08 00 03.460	+50 30 05.76	0.39	-0.16	0.42	-1	2.15	20.23	1	2.61	22.41	2.17	985	1.07	0.98	0.5	-2.2	0.8
08 00 04.050	+23 26 16.30	-2.87	1.68	3.32	2	19.81	9.92	2	21.84	11.49	1.56	226	6.00	6.23	1.1	1.0	180.0
08 00 04.378	+46 09 59.44	0.83	0.08	0.84	1	7.16	18.45	-1	1.89	22.31	3.86	1317	2.01	2.76	4.2	2.3	134.0
08 00 04.981	+28 06 08.29	-2.43	0.54	2.49	2	67.99	14.50	1	23.40	18.21	3.71	1344	1.02	1.55	4.1	3.8	90.5
08 00 05.237	+50 10 23.62	-0.44	0.16	0.47	-1	1.15	18.93	0	0.00	-22.28	-9.99	1317	3.09	3.88	5.3	-2.4	60.1
08 00 05.463	+32 11 23.10	0.43	0.77	0.88	1	7.23	20.30	0	0.00	-21.83	-9.99	1344	2.92	3.14	2.5	-1.2	23.0
08 00 06.509	+43 09 53.78	-1.72	2.62	3.14	2	8.95	20.09	0	0.00	-22.17	-9.99	1329	2.69	2.07	-2.3	-2.8	138.3
08 00 06.555	+32 01 47.98	0.85	0.40	0.94	2	10.27	20.44	0	0.00	-21.83	-9.99	1344	1.12	0.72	-2.0	-3.9	144.3
08 00 07.243	+25 22 19.95	0.36	-0.19	0.41	-1	0.29	19.99	-1	0.09	20.40	0.40	226	20.86	38.93	7.7	2.0	127.2
08 00 09.613	+38 06 50.00	0.52	0.72	0.89	1	2.07	21.03	0	0.00	-22.18	-9.99	989	1.05	1.39	5.5	-2.0	141.9
08 00 09.892	+44 36 45.86	-1.85	2.50	3.11	-1	0.11	20.60	0	0.00	-22.28	-9.99	1317	1.21	1.36	6.5	-3.7	24.4
08 00 10.262	+41 20 36.84	-1.42	-1.72	2.23	0	0.00	-20.84	1	8.15	22.12	-9.99	1329	1.36	0.80	-3.3	-3.6	91.9
08 00 10.571	+34 02 20.90	-0.19	-0.93	0.95	-1	1.24	19.27	2	6.19	22.30	3.03	989	1.60	3.45	8.9	2.7	180.0
08 00 10.974	+24 09 03.42	-3.57	-2.23	4.21	1	7.99	18.30	1	7.09	20.28	1.98	226	2.31	2.34	2.5	-2.1	6.0
08 00 11.108	+33 14 27.82	0.03	-0.71	0.71	1	2.39	21.05	0	0.00	-22.18	-9.99	989	11.21	11.67	1.4	0.7	4.3
08 00 11.197	+30 31 48.00	-0.28	-1.17	1.21	1	3.24	20.41	0	0.00	-21.83	-9.99	1344	26.07	25.93	0.4	-0.7	110.6
08 00 12.213	+22 49 27.46	-0.02	1.88	1.88	-1	0.29	19.97	0	0.00	-21.85	-9.99	226	1.37	2.14	4.3	3.9	87.2
08 00 12.515	+26 22 16.93	-2.49	-0.59	2.56	0	0.00	-20.26	1	2.03	20.53	-9.99	226	26.25	27.72	1.3	1.3	180.0
08 00 12.603	+45 39 23.51	3.34	-3.24	4.66	2	7.07	20.19	0	0.00	-22.28	-9.99	1317	1.97	3.15	4.3	4.1	0.2

Table 5: Previous Optical Identifications of Faint Radio Sources

Position	Area	$S(1.4\hbox{ GHz})$	Sources		Suggested Identifications			Referencee
(1950)	(deg$^{2}$)	(mJy)	(1-30 mJy)		POSS-I	Fainter	Total
1204+1130	9.0		102		21	-	21	1
1306+2900
1718+5000	5.5	0.6	240		45	100	145	2
0014+1530
0840+4440
0852+1716	0.44a	0.1	37		11	0	11	3
1300+3034	0.44	0.1	40		7	5	18	4
	b	0.6	66		11	14	25	5
0854+1730	9.0	6.0	130		31	0	31	6
1204+1130
0310+8008	0.13	1.0c	14		3	0	3	7
1635+6620	0.13
0015+1533	0.01	0.3c	13		1	3	4	8
NGP	12.57		168		31	35	66	9
0927+4710	12.0		329		53	4	57	10, 11
1416+5242	0.5	0.03c	6		1	1	2	12
HDF	0.02	0.02d	5		0	4	4	13
Lockman Hole	0.35	0.12	28		5	1	6	14
Phoenix Deep	3.0	0.10	270		50	12	62	15, 16
Totals:	53.1		1448		270 = 18.6%		455
This work:	4150	1.0	357,985		65,400f = 18.3%		65,400

(a) Partial overlap with the sample of reference 6

(b) Partial overlap with sample of reference 2

(c) 6 cm survey; fluxes translated to 20 cm using $\alpha \le -0.5$

(d) 3.6 cm survey; fluxes translated to 20 cm using $\alpha \le -0.5$

(e) References: 1. Condon, Condon, & Hazard 1982; 2. Windhorst, Kron, & Koo 1984; Kron, Koo, and Windhorst 1985; 3. Condon & Mitchell 1984; 4. Mitchell & Condon 1985; 5. Windhorst et al. 1985; 6. Coleman, Condon, & Hazard 1985; 7. Partridge, Hilldrup & Ratner 1986; 8. Weistrop et al. 1987; 9. Benn et al. 1988; 10. Condon, Dickey, & Salpeter 1990; 11. Lu et al. 1996; 12. Fomalont et al. 1991; 13. Richards et al. 1998; 14. deRuiter et al. 1997; 15. Hopkins et al. 1998; 16. Georgakakis et al. 1998.

(f) 65,400 is the number of 90%-confident identifications given in Table 2; it does not include lower confidence associations or objects identified with double radio sources, which boost the number of suggested identifications to $\sim 73,000$.