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Multifrequency light curves of low-frequency variable radio sources

1984; Institute of Physics; Volume: 89; Linguagem: Inglês

10.1086/113687

1538-3881

Daniel R. Altschuler, J. J. Broderick, B. Dennison, K. J. Mitchell, Stephen L. O’Dell, J. J. Condon, H. E. Payne,

Astronomical Observations and Instrumentation

view Abstract Citations (39) References (53) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Multifrequency light-curves of low-frequency variable radio sources. Altschuler, D. R. ; Broderick, J. J. ; Condon, J. J. ; Dennison, B. ; Mitchell, K. J. ; O'Dell, S. L. ; Payne, H. E. Abstract Light curves for the low-frequency variable sources AO 0235 + 16, NRAO 140, PKS 1117 + 14, DA 406, CTA 102, and 3C 454.3, obtained in monthly observations at 318, 430, and 606 MHz using the 305-m telescope at Arecibo and in bimonthly observations at 880 MHz and 1.4 GHz using the 91-m Green Bank transit telescope during 1980-1983, are presented and analyzed. AO 0235 + 16 is found to have basically canonical variability which is attributed to relativistically moving evolving synchrotron components; but in the other sources, strong simultaneous variations at 318, 430, and 606 MHz are observed to be greatly diminished in amplitude at 880 MHz and 1.4 GHz, confirming the existence of the intermediate-frequency gap at about 1 GHz proposed by Spangler and Cotton (1981). The possibility that a second variability mechanism is active in these sources is explored. Publication: The Astronomical Journal Pub Date: December 1984 DOI: 10.1086/113687 Bibcode: 1984AJ.....89.1784A Keywords: Extragalactic Radio Sources; Light Curve; Radiant Flux Density; Radio Spectra; Variability; Astronomical Spectroscopy; Error Analysis; Radio Astronomy; Relativistic Effects; Synchrotron Radiation; Ultrahigh Frequencies; Very Long Base Interferometry; Astronomy full text sources ADS | data products SIMBAD (21) NED (8)