Long-lasting X-ray emission from an active region

Title:

Long-lasting X-ray emission from an active region

Creator:

Křivský, L., Fárník, F., Sudová, J., and Valníček, B.

Identifier:

https://cdk.lib.cas.cz/client/handle/uuid:5293d177-43af-4c36-91cc-6c341d67294a
uuid:5293d177-43af-4c36-91cc-6c341d67294a

Subject:

coronographs, active regions, and long-lasting X-ray emission

Type:

model:article and TEXT

Format:

bez média and svazek

Description:

An exceptional 10-hour enhancement in the level of the soft X-ray emission, most probably originated in an exceptionally active region with flares at the eastern limb of the disk on Jan. 25, 1981, is described. This phonomenon has been called "an outstanding X-ray emission of an active region" (1984) and is documented by measurements made independently on two probes, i.e. GEQS-2 and PROGNOZ-8. The rise in the level of the X-ray emission (2-8 keV) amounted to about one order of magnitude (from l10^-6 to 10^-5 Wm^-2). The separate emission of flares are superimposed on this large enhancement. During the event, 3 outbursts were recorded int the 80 - 160 keV range, in each case at the time of recurrent flares in the region at the E limb (S 14, E 90) (Křivský and Scheirich, 1984). The most significant flares of this period were recorded by the coronograph on Lomnický štít. The flare had the form of ascending flare loops, at the sides of which ejections towards the corona or arcs receding to the disk could be observed. Radio burst of type IV and II occurred in the explosive phase of the flare, as well as a hard X-ray emission burst within the same interval in which bright flare loops were generated at the very beginning, and when partlcle acceleration apparently occurred. The fast particles were not recorded on the Earth due to its unfavourable position relative to their source and trajectory, but after 17:00 UT the X-ray photometer aboard the Prognoz-8 satellite registered a large number of unresolved fast particles (see Fig. 3). The studied phenomenon belongs to the interval of the Solar Maximum Year (Aug. 1979 - Feb. 1981).

Language:

Czech

Rights:

http://creativecommons.org/publicdomain/mark/1.0/
policy:public

Coverage:

233-236

Source:

Publications of the Astronomical Institute of the Academy of Sciences of the Czech Republic | 1987 Volume:63-70 | Number:66

Harvested from:

CDK

Metadata only:

false