Synchrotron radiation from the winds of O supergiants - Tb = 10 to the 7. 6th K at 60 stellar radii

Journal Article · Wed Aug 01 00:00:00 EDT 1990 · Astrophysical Journal; (USA)

DOI:https://doi.org/10.1086/185785· OSTI ID:6440218

Phillips, R B; Titus, M A ^[1]

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1. Haystack Observatory, Westford, MA (USA)

Results are presented on VLBI measurements of the nonthermal radio components around two O supergiant stars: Cyg OB2 No. 9 and HD 167971. The measurements were used to characterize the brightness temperature of the emission and to measure the size of compact 5-10 mJy components in these stars, reported by Bieging et al. (1989). The sizes found for the 5-10 mJy components are consistent with the free-free wind radii, indicating that the compact companions are not the sources of nonthermal radiation. Results suggest that there is a small fractional population (10 to the -4th to 10 to the -7th) of ultrarelativistic electrons (Teff of about 10 to the 11th K) coexisting with the stellar wind, which emit optically thin synchrotron radiation. This is in agreement with the synchrotron model of White (1985). 21 refs.

• OSTI ID: 6440218
• Journal Information: Astrophysical Journal; (USA), Vol. 359; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
STELLAR WINDS
SYNCHROTRON RADIATION
SUPERGIANT STARS
BRIGHTNESS
INTERFEROMETRY
RADIOWAVE RADIATION
RESOLUTION
SIZE
BREMSSTRAHLUNG
ELECTROMAGNETIC RADIATION
GIANT STARS
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
RADIATIONS
STARS
STELLAR ACTIVITY
640102* - Astrophysics & Cosmology- Stars & Quasi-Stellar
Radio & X-Ray Sources