Solar flares with Hard X-rays (HXR) detected by SONG ( CORONAS-F) [2004, 2005]

It is well known that the Sun is the most energetic particle accelerator in the Solar system, producing ions of up to tens of GeV and electrons of up to tens of MeV. The information regarding peak gamma emission energy obtained by the SONG experiment allows us to estimate the flux and spectra of the charged particles accelerated in the Solar atmosphere.

The CORONAS-F duty cycle of solar flare detection was approximately 40% as a consequence of its orbital parameters; thus many major flares that occurred since August 14, 2001 till September 12, 2005 were not observed. Still, 9 flares with HXR emission have been detected by CORONAS-F during 2004 and 23 ones during 2005.

Characteristics of the SONG flares (detection time and peak gamma ray energy channel) as well as soft X-ray (SXR) GOES characteristics are presented in Table 1. Apparently HXR emission was observed not only in major X-class flares in SXR; there are several M and C class (in SXR) flares accompanied by HXR emission. Such hard spectra of energetic neutral emission indicate that the charged energetic particles were accelerated in this flare up to rather high energies.The comparison of number of gamma flares observed in different years shows that flares producing HXR and gamma emission also occur close to the minimum of Solar activity cycle.

Click the index of HXR emission to view the graphic representation of HXR-ray count rates detected by SONG and a RHESSY data to view the graphic representation of RHESSI data.

Solar flares with HXR and gamma-emission detected by SONG (CORONAS-F) experiment [2004]
N	Date	SHR-flare UT (GOES) start-peak-end	SONG UT (42-80keV)	SXR-class	Coordinates	Active Region	Maximum, MeV	RHESSI data	SONG data comments
1	06.01	06:13-06:29-06:36	06:22-06:24	M5.8	N05E90	0537	5.2-9.1	Yes
2	08.01	04:53-05:07-05:21	04:55-05:01	M1.3	N01E64	0537	0.07-0.18	Yes
3	11.04	03:54-04:19-04:35	04:13-04.18	C9.6	S16W46	0588	0.07-0.18	Yes
4	30.10	11:38-11:46-11:50	11:43-11:44	X1.2	N12W26	0691	0.07-0.18	No	ERB from 11:45
5	30.10	16:18-16:33-16:37	16:24-16:25	M5.9	N13W28	0691	0.07-0.18	Partial	ERB till 16:24
6	03.11	01:23-01:33-01:37	01:26-01:33	M2.8	N12W75	0691	0.07-0.18	No
7	04.11	22:53-23:09-23:26	22:53-23:01	M5.4	N08E18	0696	0.07-0.18	Yes
8	08.11	14:30-14:35-14:38	14:34-14:35	C7.7	N06W35	0696	0.07-0.18	No
9	30.12	22:02-22:18-22:28	22:10-22:12	M4.6	N04E46	0715	0.07-0.18	No

Solar flares with HXR and gamma-emission detected by SONG (CORONAS-F) experiment [2005]
N	Date	SHR-flare UT (GOES) start-peak-end	SONG UT (42-80keV)	SXR-class	Coordinates	Active Region	Maximum, MeV	RHESSI data	SONG data comments
1	01.01	00:01-00:31-00:39	00:27-00:37	X1.7	N06E34	0715	2-6	No
2	14.01	21:08-21:26-21:39	21:16-21:24	M1.9	N14E10	0720	0.08-0.225	Yes	Several short peaks
3	15.01	00:22-00:43-01:02	00:39-00:42	X1.2	N14E08	0720	0.225-0.75	Yes	Middle latitudes
4	15.01	05:54-06:38-07:17	06:24-06:32	M8.6	N16E04	0720	0.08-0.225	Partial	ERB till 06:24
5	15.01	22:25-23:02-23:31	20:38-20:55	X2.6	N15W05	0720	0.225-0.75	Yes	In a polar cap
6
7	17.01	06:59-09:52-10:07	09:06-10:00	X3.8	N15W25	0720	2-6	Partial	Gap in 09:16-09:52
8	18.01	15:38-15:51-15:59	15:46-15:47	M4.6	N15W42	0720	0.08-0.225	No
9	19.01	08:03-08:22-08:40	08:08-08:15	X1.3	N15W51	0720	0.08-0.225	Partial	Shade till 08:08
10	20.01	06:36-07:01-07:26	09:47-09:58	X7.1	N14W61	0720	90-150	Yes
11	21.01	10:10-10:16-10:19	10:14-10:16	M1.7	N19W81	0720	0.225-0.75	Yes
12	06.05	03:05-03:14-03:21	03:07-03:12	C9.3	S04W71	0756	0.08-0.225	Yes
13	16.06	20:01-20:22-21:10	20:50-20:53	M4.0	N08W90	0775	0.08-0.225	Yes	HXR after maximum
14	14.07	05:57-07:25-07:43	07:22-07:24	M9.1	N09W90	0786	2-6	No
15	14.07	10:16-10:17-10:55	10:25-10:28	X1.2	N12E60	0788	0.08-0.225	Partial
16	28.07	21:39-22:08-22:24	21:49-21:55	M4.8	N09E82	0792	0.08-0.225	No
17	30.07	06:17-06:35-07:01	06:12-06:28	X1.3	N12E60	0792	0.225-0.75	Partial
18	23.08	14:19-14:44-16:08	14:36-14:40	M2.7	S14W90	0798	0.08-0.225	ERB
19	08.09	20:52-21:06-21:17	21:04-21:06	X5.4	S12E75	0808	0.08-0.225	No	Small peak
20	09.09	19:13-20:04-20:36	20:00-20:16	X6.2	S12E67	0808	2-6	Partial	Shade till 20:00
21	10.09	21:30-22:11-22:43	21:45-22:15	X2.1	S13E47	0808	0.75-2	Yes
22	12.09	08:37-09:03-09:20	08:45-08:49	M6.2	S11E25	0808	2-6	Partial