Solar gradual hard X-ray bursts and associated phenomena

Journal Article · Sun Jun 01 04:00:00 EDT 1986 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/164306· OSTI ID:5228491

Cliver, E W; Dennis, B R; Kiplinger, A L; Kane, S R; Neidig, D F

White-light coronagraph, H-alpha and radio data are presented as well as hard X-ray data for a sample of 10 gradual hard X-ray bursts (GHBs) in an attempt to better understand the nature of these events. It is found that: (1) the hard X-ray photon energy spectrum began to harden near the onset of the GHBs and continued in this fashion during the decay phase; (2) a coronal mass ejection (CME) occurred in association with at least nine of the GHBs; (3) the GHBs occurred in the late phase of major flares; (4) the centimeter wavelength bursts associated with the GHBs had relatively low frequency spectral maxima, and in relation to the observed hard X-ray emission, they were microwave-rich; (5) the associated decimetric bursts showed significant intensity variations on time scales ranging from 0.1 to approximately greater than 1 minute; and (6) the GHBs were most strongly associated with type IV events. It is concluded that the acceleration and trapping of radiating electrons occurs in the postflare loop systems following CMEs. 104 references.

• Research Organization: USAF, Geophysics Lab., Bedford, MA; NASA, Goddard Space Flight Center, Greenbelt, MD; California Univ., Berkeley; Sacramento Peak Observatory, Sunspot, NM
• OSTI ID: 5228491
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 305; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640104* -- Astrophysics & Cosmology-- Solar Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ATMOSPHERES
BALMER LINES
ELECTROMAGNETIC RADIATION
ELECTRONS
ELEMENTARY PARTICLES
FERMIONS
HARD X RADIATION
IONIZING RADIATIONS
LEPTONS
MAGNETIC FIELDS
RADIATIONS
RADIOWAVE RADIATION
SOLAR ACTIVITY
SOLAR CORONA
SOLAR ELECTRONS
SOLAR FLARES
SOLAR PARTICLES
SOLAR RADIATION
SOLAR RADIO BURSTS
SOLAR X-RAY BURSTS
STELLAR ATMOSPHERES
STELLAR CORONAE
STELLAR RADIATION
X RADIATION