UCL Discovery
UCL home » Library Services » Electronic resources » UCL Discovery

A catalogue of white-light flares observed by Yohkoh

Matthews, SA; van Driel-Gesztelyi, L; Hudson, HS; Nitta, NV; (2003) A catalogue of white-light flares observed by Yohkoh. ASTRON ASTROPHYS , 409 (3) 1107 - 1125. 10.1051/0004-6361:20031187. Green open access

[thumbnail of 9750.pdf]
Preview
PDF
9750.pdf

Download (815kB)

Abstract

The aspect camera of the Soft X-ray Telescope (SXT) on Yohkoh provided the first systematic survey of white-light flares from an observatory in space. The observations were made in the Fraunhofer g-band at a pixel size of 2.46 arcsec and a typical sample interval on the order of ten seconds. A total of 28 flares with clear white-light signatures were detected, corresponding to GOES events down to the C7.8 level in one case. Above the X-class threshold, all 5 events observed by SXT were observed in white light, and the maximum average contrast observed was 30% relative to the pre-flare continuum brightness of the flare location. We have made comprehensive comparisons of Yohkoh soft X-ray and hard X-ray data for this list of flares. In addition we compare the properties of the WLF sample to a sample of 31 flares that showed no white-light emission. These comparisons show that while white-light continuum emission has a strong association with hard X-ray emission it is also strongly related to coronal overpressure, as determined from the soft X-ray spectrum, indicating a component with a thermal, rather than non-thermal origin.

Type: Article
Title: A catalogue of white-light flares observed by Yohkoh
Open access status: An open access version is available from UCL Discovery
DOI: 10.1051/0004-6361:20031187
Keywords: Sun : flares, Sun : X-rays, gamma rays, SOLAR-A MISSION, X-RAY TELESCOPE, HARD, TEMPERATURE, IONIZATION, SEARCH
UCL classification: UCL
UCL > Provost and Vice Provost Offices > UCL BEAMS
UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences
UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Space and Climate Physics
URI: https://discovery.ucl.ac.uk/id/eprint/9750
Downloads since deposit
244Downloads
Download activity - last month
Download activity - last 12 months
Downloads by country - last 12 months

Archive Staff Only

View Item View Item