Low-frequency radio spectra of SCO X-1

• Published in: Monthly notices of the Royal Astronomical Society Vol. 239; no. 1; pp. 281 - 288
• Main Authors: Velusamy, T., Subrahmanya, C. R.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Oxford University Press 01.07.1989; Blackwell Science
• Subjects: Astronomy; Earth, ocean, space; Exact sciences and technology; Stellar systems. Galactic and extragalactic objects and systems. The universe; Unidentified sources and radiation outside the solar system; X-ray sources ; x-ray bursts; Radio emission; Radio map; Binary X ray source; X ray binary; Low frequency; Radio observation; Galactic radiosource; Radio spectrum
• ISSN: 0035-8711; 1365-2966
• DOI: 10.1093/mnras/239.1.281

New observations of Sco X-1 at 327 and 843 MHz with the Ooty Synthesis Radio Telescope (OSRT) and the Molonglo Observatory Synthesis Telescope (MOST) are presented. The north-eastern component in the Sco X-1 shows a spectral turnover at about 1.5 GHz. The central component was not detected at these frequencies. The south-western component shows a power-law spectrum with a $\propto \enspace\approx-0.75$ between 0.3 and 5 GHz. The radio structure and spectra of Sco X-1 resemble those of extragalactic Compact Doubles. The spectral turnover indicates a compact size < 1 mas for the north-eastern component, which poses difficulties for ram-pressure confinement. The association of an outer pair of sources, 1617–153 and 1616–160, collinear with the inner triple sources, is discussed in the light of models with magnetic focusing.