Zobrazeno 1 - 10
of 97
pro vyhledávání: '"Bignall, Hayley"'
Autor:
Bignall, Hayley E., Tuntsov, Artem V., Stevens, Jamie, Bannister, Keith, Walker, Mark A., Reynolds, Cormac
We discovered rapid intra-day variability in radio source PMN J1726+0639 at GHz frequencies, during a survey to search for such variability with the Australia Telescope Compact Array. Follow-up observations were conducted over two years and revealed
Externí odkaz:
http://arxiv.org/abs/2204.05847
Autor:
Madrid, Juan P., Tuntsov, Artem V., Schirmer, Mischa, Walker, Mark A., Donzelli, Carlos J., Bannister, Keith W., Bignall, Hayley E., Stevens, Jamie, Reynolds, Cormac, Johnston, Simon
Publikováno v:
The Astrophysical Journal, 900, 169 (2020)
Observations with the Australia Telescope Compact Array revealed intra-hour variations in the radio source PKS B1322-110 (Bignall et al. 2019). As part of an optical follow-up, we obtained Gemini Halpha and Halpha continuum (HalphaC) images of the PK
Externí odkaz:
http://arxiv.org/abs/2009.06447
Autor:
Oosterloo, Tom, Morganti, Raffaella, Tadhunter, Clive, Oonk, J. B. Raymond, Bignall, Hayley E., Tzioumis, Tasso, Reynolds, Cormac
Publikováno v:
A&A 632, A66 (2019)
We present CO(1-0) and CO(3-2) ALMA observations of the molecular gas in PKS 1549-79, as well as mm and VLBI 2.3-GHz continuum observations of its radio jet. PKS 1549-79 is one of the closest young, radio-loud quasars caught in an on-going merger in
Externí odkaz:
http://arxiv.org/abs/1910.07865
Autor:
Liu, Jun, Krichbaum, Thomas P., Bignall, Hayley, Liu, Xiang, Kraus, Alex, Kovalev, Yuri Y., Sokolovsky, Kirill V., Cimò, Giuseppe, Zensus, J. Anton
Publikováno v:
POS(EVN2018)112
The RadioAstron space radio telescope provides a unique opportunity to study the extreme brightness temperatures ($\mathrm{T_B }$) in AGNs with unprecedented long baselines of up to 28 Earth diameters. Since interstellar scintillation (ISS) may affec
Externí odkaz:
http://arxiv.org/abs/1909.01043
Autor:
Bignall, Hayley, Reynolds, Cormac, Stevens, Jamie, Bannister, Keith, Johnston, Simon, Tuntsov, Artem V., Walker, Mark A., Gulyaev, Sergei, Natusch, Tim, Weston, Stuart, Said, Noor Masdiana Md, Kratzer, Matthew
PKS B1322-110 is a radio quasar that is located only 8.5' in angular separation from the bright B star Spica. It exhibits intra-day variability in its flux density at GHz frequencies attributed to scintillations from plasma inhomogeneities. We have t
Externí odkaz:
http://arxiv.org/abs/1906.01141
Autor:
Liu, Jun, Bignall, Hayley, Krichbaum, Thomas P., Liu, Xiang, Kraus, Alex, Kovalev, Yuri Y., Sokolovsky, Kirill V., Angelakis, Emmanouil, Zensus, J. Anton
Publikováno v:
Galaxies 2018, Vol. 6(2), p. 49
We present the first results of an ongoing intra-day variability (IDV) flux density monitoring program of 107 blazars, which were selected from a sample of RadioAstron space very long baseline interferometry (VLBI) targets. The~IDV observations were
Externí odkaz:
http://arxiv.org/abs/1804.09289
Autor:
Tuntsov, Artem V., Stevens, Jamie, Bannister, Keith W., Bignall, Hayley, Johnston, Simon, Reynolds, Cormac, Walker, Mark A.
We report radio observations of the quasar PMN J1106-3647. Our data, taken with the Australia Telescope Compact Array, show large variations in the amplitude and shape of its spectrum, on a short time-scale. A great variety of spectral features is ev
Externí odkaz:
http://arxiv.org/abs/1705.06051
Autor:
Walker, Mark, Tuntsov, Artem, Bignall, Hayley, Reynolds, Cormac, Bannister, Keith, Johnston, Simon, Stevens, Jamie, Ravi, Vikram
We use data on extreme radio scintillation to demonstrate that this phenomenon is associated with hot stars in the solar neighbourhood. The ionized gas responsible for the scattering is found at distances up to 1.75pc from the host star, and on avera
Externí odkaz:
http://arxiv.org/abs/1705.00964
Autor:
Bannister, Keith W., Stevens, Jamie, Tuntsov, Artem V., Walker, Mark A., Johnston, Simon, Reynolds, Cormac, Bignall, Hayley
Publikováno v:
Science 22 Jan 2016. Vol. 351, Issue 6271, pp. 354-356
Extreme scattering events (ESEs) are distinctive fluctuations in the brightness of astronomical radio sources caused by occulting plasma lenses in the interstellar medium. The inferred plasma pressures of the lenses are $\sim 10^3$ times the ambient
Externí odkaz:
http://arxiv.org/abs/1601.05876
Autor:
Tuntsov, Artem V., Walker, Mark A., Koopmans, Leon V. E., Bannister, Keith W., Stevens, Jamie, Johnston, Simon, Reynolds, Cormac, Bignall, Hayley E.
Publikováno v:
2016, ApJ, 817, 176
Compact radio sources sometimes exhibit intervals of large, rapid changes in their flux-density, due to lensing by interstellar plasma crossing the line-of-sight. A novel survey program has made it possible to discover these "Extreme Scattering Event
Externí odkaz:
http://arxiv.org/abs/1512.03411