Table 3: Statistics of the field-star decontamination, in magnitude bins, for representative cases.
FSR 942 ( $R<3\hbox {$^\prime $ }$ ) FSR 855 ( $R<3\hbox {$^\prime $ }$ ) FSR 801 ( $R<3\hbox {$^\prime $ }$ )

$\Delta\mbox{$\space J$ }$ $N_{\rm obs}$ $N_{\rm cl}$ $N_{1\sigma}$ $\sigma_{\rm FS}$ $FS_{\rm unif}$ $N_{\rm obs}$ $N_{\rm cl}$ $N_{1\sigma}$ $\sigma_{\rm FS}$ $FS_{\rm unif}$ $N_{\rm obs}$ $N_{\rm cl}$ $N_{1\sigma}$ $\sigma_{\rm FS}$ $FS_{\rm unif}$

(mag) (stars) (stars) (stars) (stars) (stars) (stars) (stars) (stars) (stars)

7-8 - - - - - $1\pm1.0$ 1 1.0 0.42 1.07 - - - - -

8-9 - - - - - - - - - - - - - - -

9-10 - - - - - $1\pm1.0$ 1 1.0 0.99 1.42 - - - - -

10-11 $3\pm1.7$ 3 1.7 0.57 0.51 $5\pm2.2$ 1 0.4 1.12 1.02 - - - - -

11-12 $4\pm2.0$ 4 2.0 0.38 0.18 $4\pm2.0$ 2 1.0 1.70 0.49 $2\pm1.4$ 1 0.7 0.18 0.23

12-13 $7\pm2.6$ 1 0.4 0.50 0.12 $6\pm2.4$ 1 0.4 3.09 0.43 $4\pm2.0$ 2 1.0 0.30 0.20

13-14 $24\pm4.9$ 17 3.5 0.75 0.08 $20\pm4.5$ 3 0.7 2.47 0.19 $4\pm2.0$ 2 1.0 0.36 0.10

14-15 $38\pm6.2$ 21 3.4 1.61 0.09 $33\pm5.7$ 6 1.0 6.27 0.26 $9\pm3.0$ 3 1.0 0.72 0.11

15-16 $63\pm7.9$ 27 3.4 2.87 0.08 $56\pm7.5$ 12 1.6 5.31 0.11 $25\pm5.0$ 9 1.8 1.60 0.12

16-17 $45\pm6.7$ 21 3.1 4.91 0.14 $72\pm8.5$ 29 3.4 6.14 0.12 $21\pm4.6$ 8 1.7 1.78 0.09

All $184\pm13.6$ 94 6.8 3.2 0.03 $198\pm14.1$ 56 3.6 11.1 0.07 $65\pm8.1$ 25 2.9 2.8 0.06

The table provides, for each magnitude bin ( $\Delta\mbox{$\space J$ }$ ), the number of observed stars ( $N_{\rm obs}$ ) within the spatial region sampled in the CMDs shown in the top panels of Figs. 3 and 4, the respective number of probable member stars ( $N_{\rm cl}$ ) computed by the decontamination algorithm, the $N_{1\sigma}$ parameter, the 1 $\sigma$ Poisson fluctuation ( $\sigma_{\rm FS}$ ) around the mean, with respect to the star counts measured in the 8 sectors of the comparison field, and the field-star uniformity parameter ( $FS_{\rm unif}$ ). The statistical significance of $N_{\rm cl}$ is reflected in its ratio with the 1 $\sigma$ Poisson fluctuation of $N_{\rm obs}$ ( $N_{1\sigma}$ ) and with $\sigma_{\rm FS}$ . The bottom line corresponds to the full magnitude range.

**Table 3:** Statistics of the field-star decontamination, in magnitude bins, for representative cases.
	FSR 942 ( $R<3\hbox {$^\prime $ }$ )		FSR 855 ( $R<3\hbox {$^\prime $ }$ )		FSR 801 ( $R<3\hbox {$^\prime $ }$ )
$\Delta\mbox{$\space J$ }$	$N_{\rm obs}$	$N_{\rm cl}$	$N_{1\sigma}$	$\sigma_{\rm FS}$	$FS_{\rm unif}$	$N_{\rm obs}$	$N_{\rm cl}$	$N_{1\sigma}$	$\sigma_{\rm FS}$	$FS_{\rm unif}$	$N_{\rm obs}$	$N_{\rm cl}$	$N_{1\sigma}$	$\sigma_{\rm FS}$	$FS_{\rm unif}$
(mag)	(stars)	(stars)		(stars)		(stars)	(stars)		(stars)		(stars)	(stars)		(stars)
7-8	-	-	-	-	-	$1\pm1.0$	1	1.0	0.42	1.07	-	-	-	-	-
8-9	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-
9-10	-	-	-	-	-	$1\pm1.0$	1	1.0	0.99	1.42	-	-	-	-	-
10-11	$3\pm1.7$	3	1.7	0.57	0.51	$5\pm2.2$	1	0.4	1.12	1.02	-	-	-	-	-
11-12	$4\pm2.0$	4	2.0	0.38	0.18	$4\pm2.0$	2	1.0	1.70	0.49	$2\pm1.4$	1	0.7	0.18	0.23
12-13	$7\pm2.6$	1	0.4	0.50	0.12	$6\pm2.4$	1	0.4	3.09	0.43	$4\pm2.0$	2	1.0	0.30	0.20
13-14	$24\pm4.9$	17	3.5	0.75	0.08	$20\pm4.5$	3	0.7	2.47	0.19	$4\pm2.0$	2	1.0	0.36	0.10
14-15	$38\pm6.2$	21	3.4	1.61	0.09	$33\pm5.7$	6	1.0	6.27	0.26	$9\pm3.0$	3	1.0	0.72	0.11
15-16	$63\pm7.9$	27	3.4	2.87	0.08	$56\pm7.5$	12	1.6	5.31	0.11	$25\pm5.0$	9	1.8	1.60	0.12
16-17	$45\pm6.7$	21	3.1	4.91	0.14	$72\pm8.5$	29	3.4	6.14	0.12	$21\pm4.6$	8	1.7	1.78	0.09
All	$184\pm13.6$	94	6.8	3.2	0.03	$198\pm14.1$	56	3.6	11.1	0.07	$65\pm8.1$	25	2.9	2.8	0.06

Source LaTeX | All tables | In the text