The BeppoSAX WFCs

The great number, 52 to date (Dec 2001), of bursts that have been promptly localized by the WFCs, still one of the highest numbers, clearly shows the good combination of an X-ray ($2-28$ keV), wide field ($20$$^\circ$x $20$$^\circ$, FWHM) camera (tab. ) with an open field Gamma-Ray Burst Monitor ($40-700$ keV). In addition to the imaging capabilities of the WFCs (few arcmins just after a few hours after the burst), the possibility of analysing the data once per orbit, together with the capability of the BeppoSAX Science Operation Center of planning a ToO (Target of Opportunity) with the more sensitive Narrow Field Instruments just few hours after the event, has come out to be a success key for delivering a fast and precise position and for detecting the first X-ray afterglows from GRB sources. Currently, the mean WFC burst rate is about 52/65 $= 0.8$ burst/month, or $\sim$ 10 GRB per year; obviously, this low rate is connected with the small field of view of the WFCs.

While a more detailed description of the BeppoSAX Wide Field Cameras (fig. ) is given in the next chapter, an updated list of the WFC bursts is reported in table; there, it has to be pointed out that the error radii have been rounded up.

Table: WFC GRBs List (July 1996 - December 2001)

GRB Date	UT	R.A.($\rm ^{\circ}$)	Decl. ($\rm ^{\circ}$)	Err. Rad. ($\rm ^{\circ}$)
20 Jul 1996	11:36:53	262.65	49.08	0.050
11 Jan 1997	09:44:00	232.06	19.60	0.050
28 Feb 1997	02:58:01	75.49	11.77	0.050
02 Apr 1997	22:18:36	222.57	-69.32	0.050
08 May 1997	21:41:47	103.37	79.28	0.050
14 Dec 1997	23:20:42	179.12	65.20	0.100
27 Dec 1997	08:23:06	194.40	59.25	0.100
09 Jan 1998	01:12:26	6.48	-63.02	0.200
26 Mar 1998	21:18:53	129.11	-18.88	0.100
29 Mar 1998	03:44:26	105.67	38.83	0.050
25 Apr 1998	21:49:08	293.73	-52.82	0.100
15 May 1998	17:00:20	319.52	-67.23	0.100
19 May 1998	12:20:22	350.56	77.25	0.050
13 Jun 1998	04:51:06	154.44	71.48	0.100
26 Dec 1998	09:47:25	352.42	-23.92	0.100
23 Jan 1999	09:47:10	231.37	44.75	0.030
17 Feb 1999	05:23:27	45.51	-53.10	0.050
10 May 1999	08:49:09	204.53	-80.50	0.050
20 May 1999	02:02:58	128.77	51.30	0.050
25 Jun 1999	00:24:34	6.64	-31.20	0.100
27 Jun 1999	05:00:51	27.10	-77.08	0.050
04 Jul 1999	17:30:20	184.79	-3.80	0.100
05 Jul 1999	16:01:25	77.38	-72.15	0.100
12 Jul 1999	16:43:02	337.96	-73.40	0.030
06 Aug 1999	14:28:07	47.65	-68.12	0.030
07 Sep 1999	17:35:11	112.70	-69.40	0.100
08 Sep 1999	00:18:00	103.23	-74.98	0.100
14 Oct 1999	21:52:33	102.78	11.60	0.100
05 Nov 1999	16:40:44	180.75	-66.80	0.100
06 Nov 1999	10:54:27	336.20	54.37	0.100
17 Dec 1999	04:12:20	345.81	0.25	0.100
10 Feb 2000	08:44:05	29.81	-40.67	0.050
08 Feb 2000	04:21:11	28.90	-22.84	0.100
14 Feb 2000	01:01:00	283.57	-66.45	0.100
16 Apr 2000	14:32:54	258.86	-71.60	0.100
24 Apr 2000	18:18:07	104.72	49.87	0.050
28 May 2000	08:46:24	161.35	-34.00	0.100
29 May 2000	08:43:12	2.28	-61.53	0.100
08 Jun 2000	08:51:42	6.25	-69.03	0.100
15 Jun 2000	06:17:48	233.14	73.80	0.100
20 Jun 2000	05:33:33	113.82	69.20	0.100
11 Oct 2000	15:54:50	275.77	-50.90	0.100
09 Nov 2000	09:23:17	277.53	55.30	0.300
14 Feb 2001	08:48:11	265.24	48.58	0.050
20 Feb 2001	22:51:07	39.25	61.77	0.100
22 Feb 2001	07:23:30	223.05	43.02	0.050

Table: (continue)

GRB Date	UT	R.A.($\rm ^{\circ}$)	Decl. ($\rm ^{\circ}$)	Err. Rad. ($\rm ^{\circ}$)
04 Mar 2001	05:18:51	316.59	53.21	1.000
12 Apr 2001	21:46:29	290.91	13.62	0.100
01 May 2001	06:37:27	286.71	-70.18	0.100
18 May 2001	06:43:10	161.68	-57.78	0.100
21 Nov 2001	18:47:11	173.63	-76.03	0.050
11 Dec 2001	19:09:21	168.81	-21.94	0.083