A study of solar flare energy transport based on coordinated H-alpha and X-ray observations

Journal Article · Fri Feb 01 04:00:00 EST 1991 · Astrophysical Journal; (USA)

DOI:https://doi.org/10.1086/169663· OSTI ID:6002349

Canfield, R C; Wulser, J; Zarro, D M; Dennis, B R ^[1]

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1. Hawaii Univ., Honolulu (USA) NASA, Goddard Space Flight Center, Greenbelt, MD (USA) Applied Research Corp., Landover, MD (USA) Lockheed Research Laboratories, Palo Alto, CA (USA)

The temporal evolution of the ratio between H-alpha to nonthermal hard X-ray emission was investigated using coordinated H-alpha and hard- and soft-X-ray observations of five solar flares (on May 7, June 23, June 24, and June 25, 1980 and on April 30, 1985). These observations were used to estimate the emitted flare energy flux F(H-alpha) in H-alpha, the flux of F(2O) energy deposited by nonthermal electrons with energies above 20 keV, and the pressure p(c) of soft X-ray-emitting plasma as functions of time during the impulsive phase of each flare. It was found that the F(H-alpha)/F(2O) ratio shows a power-law dependence on F(2O), with a slope that differs slightly from that predicted by the static thick-target model of solar transport. Results also indicate that the power-law dependence is modified by hydrostatic pressure effects. 25 refs.

• OSTI ID: 6002349
• Journal Information: Astrophysical Journal; (USA), Journal Name: Astrophysical Journal; (USA) Vol. 367; ISSN ASJOA; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

640104* -- Astrophysics & Cosmology-- Solar Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ATMOSPHERES
BALMER LINES
CHROMOSPHERE
ELECTROMAGNETIC RADIATION
EMISSION SPECTRA
ENERGY TRANSFER
HARD X RADIATION
HYDROSTATICS
IONIZING RADIATIONS
PRESSURE EFFECTS
RADIATION FLUX
RADIATIONS
SOLAR ACTIVITY
SOLAR ATMOSPHERE
SOLAR CORONA
SOLAR FLARES
SPECTRA
STELLAR ATMOSPHERES
STELLAR CORONAE
X RADIATION