PSR B0329+54: STATISTICS OF SUBSTRUCTURE DISCOVERED WITHIN THE SCATTERING DISK ON RADIOASTRON BASELINES OF UP TO 235,000 km
Year: 2016
Type: article
Abstract: ABSTRACT We discovered fine-scale structure within the scattering disk of PSR B0329+54 in observations with the RadioAstron ground–space radio interferometer. Here we describe this phenomenon, characterize it with averages and correlation functions, and interpret it as the result of decorrelation of the impulse-response function of interstellar scattering between the widely separated antennas. This instrument included the 10 m Space Radio Telescope, the 110 m Green Bank Telescope, the 14 × 25 m Westerbork Synthesis Radio Telescope, and the 64 m Kalyazin Radio Telescope. The observations were performed at 324 MHz on baselines of up to 235,000 km in 2012 November and 2014 January. In the delay domain, on long baselines the interferometric visibility consists of many discrete spikes within a limited range of delays. On short baselines it consists of a sharp spike surrounded by lower spikes. The average envelope of correlations of the visibility function shows two exponential scales, with characteristic delays of τ 1 = 4.1 ± 0.3 μ s and τ 2 = 23 ± 3 μ s , indicating the presence of two scales of scattering in the interstellar medium. These two scales are present in the pulse-broadening function. The longer scale contains 0.38 times the scattered power of the shorter one. We suggest that the longer tail arises from highly scattered paths, possibly from anisotropic scattering or from substructure at large angles.
Source: The Astrophysical Journal
Authors: C. R. Gwinn, M. V. Popov, N. Bartel, A. S. Andrianov, M. D. Johnson, B. C. Joshi, N. S. Kardashev, R. Karuppusamy, Y. Y. Kovalev, M. Kramer, A. G. Rudnitskii, E. R. Safutdinov, V. I. Shishov, T. V. Smirnova, V. A. Soglasnov, S. F. Steinmassl, J. A. Zensus, V. I. Zhuravlev
Institutions: University of California, Santa Barbara, P.N. Lebedev Physical Institute of the Russian Academy of Sciences, Astro Space Center, York University, Center for Astrophysics Harvard & Smithsonian, National Centre for Radio Astrophysics, Max Planck Institute for Radio Astronomy, Moscow Institute of Physics and Technology, Technical University of Munich
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W2301650955