Solar active region physical parameters inferred from a thermal cyclotron line and soft X-ray spectral lines

Journal Article · Sun Nov 01 04:00:00 EST 1987 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/165799· OSTI ID:5404159

Lang, K R; Willson, R F; Smith, K L; Strong, K T

Simultaneous high-resolution observations of coronal loops were made at the 20-cm wavelength with the VLA and at soft X-ray wavelengths with the SMM FCS. The images obtained at both wavelengths have nearly identical sizes and ellipsoidal shapes, with the emission stretching between and across regions of opposite magnetic polarity in the underlying photosphere. The results indicate that the radiation at 20 cm and soft X-ray wavelengths originates from the same region, and that 20 cm maps can image X-ray coronal loops. The X-ray spectral lines were used to obtain values of electron temperature, T(e), of about 2.6 x 10 to the 6th K and electron density, N(e), of about 3.1 x 10 to the 9th/cu cm. These parameters were used to show that the layers emitting 20-cm radiation can be optically thick to either thermal bremsstrahlung or thermal gyroresonance radiation, depending upon unknown but plausible values of loop thickness, magnetic scale height, and magnetic field strength. 13 references.

• Research Organization: Tufts Univ., Medford, MA; Lockheed Research Labs., Palo Alto, CA
• OSTI ID: 5404159
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 322; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640104* -- Astrophysics & Cosmology-- Solar Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ELECTROMAGNETIC RADIATION
ELECTRON DENSITY
ELECTRON TEMPERATURE
IONIZING RADIATIONS
MAGNETIC FIELDS
RADIATIONS
RADIOWAVE RADIATION
SOFT X RADIATION
SOLAR ACTIVITY
SOLAR PROMINENCES
X RADIATION