G-BAND AND HARD X-RAY EMISSIONS OF THE 2006 DECEMBER 14 FLARE OBSERVED BY HINODE/SOT AND RHESSI

Journal Article · Thu May 20 04:00:00 EDT 2010 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/715/1/651· OSTI ID:21448721

Watanabe, Kyoko; Shimizu, Toshifumi ^[1]; Krucker, Saem; Hudson, Hugh ^[2]; Masuda, Satoshi ^[3]; Ichimoto, Kiyoshi ^[4]

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1. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5210 (Japan)
2. Space Sciences Laboratory, University of California at Berkeley, 7 Gauss Way, Berkeley, CA 94720-7450 (United States)
3. Solar-Terrestrial Environment Laboratory, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601 (Japan)
4. Kwasan and Hida Observatories, Kyoto University, Yamashina, Kyoto 607-8471 (Japan)

We report on G-band emission observed by the Solar Optical Telescope on board the Hinode satellite in association with the X1.5-class flare on 2006 December 14. The G-band enhancements originate from the footpoints of flaring coronal magnetic loops, coinciding with nonthermal hard X-ray bremsstrahlung sources observed by the Reuven Ramaty High Energy Solar Spectroscopic Imager. At the available 2 minute cadence, the G-band and hard X-ray intensities are furthermore well correlated in time. Assuming that the G-band enhancements are continuum emission from a blackbody, we derived the total radiative losses of the white-light flare (white-light power). If the G-band enhancements additionally have a contribution from lines, the derived values are overestimates. We compare the white-light power with the power in hard X-ray producing electrons using the thick-target assumption. Independent of the cutoff energy of the accelerated electron spectrum, the white-light power and the power of accelerated electrons are roughly proportional. Using the observed upper limit of {approx}30 keV for the cutoff energy, the hard X-ray producing electrons provide at least a factor of 2 more power than needed to produce the white-light emission. For electrons above 40 keV, the powers roughly match for all four of the time intervals available during the impulsive phase. Hence, the flare-accelerated electrons contain enough energy to produce the white-light flare emissions. The observed correlation in time, space, and power strongly suggests that electron acceleration and white-light production in solar flares are closely related. However, the results also call attention to the inconsistency in apparent source heights of the hard X-ray (chromosphere) and white-light (upper photosphere) sources.

• OSTI ID: 21448721
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 715; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ATMOSPHERES
BREMSSTRAHLUNG
CHROMOSPHERE
ELECTROMAGNETIC RADIATION
ELECTRON SPECTRA
FLARING
HARD X RADIATION
IONIZING RADIATIONS
MAIN SEQUENCE STARS
PHOTOSPHERE
RADIATIONS
SATELLITES
SOLAR ACTIVITY
SOLAR ATMOSPHERE
SOLAR FLARES
SPECTRA
STARS
STELLAR ACTIVITY
STELLAR ATMOSPHERES
STELLAR FLARES
SUN
TELESCOPES
X RADIATION