Hostname: page-component-cc8bf7c57-pd9xq Total loading time: 0 Render date: 2024-12-12T07:53:12.876Z Has data issue: false hasContentIssue false
  • English
  • Français

Galactic Plane Surveys at Low Frequencies

Published online by Cambridge University Press:  26 May 2016

A.R. Taylor
A.R. Taylor*
Affiliation:
University of Calgary, Physics and Astronomy, 2500 University DR. N.W., Calgary, Alberta, Canada, T2N 1N4

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Until recently, high angular resolution and high sensitivity surveys of the radio emission from the plane of our Galaxy were available only at frequencies of several GHz, where large single dish radio telescopes provide arcminute scale angular resolution. At these frequencies thermal radiation from HII regions and diffuse ionized gas comprise a major component of the Galactic emission. Advances in wide field interferometric imaging techniques now make it possible to carry out high sensitivity surveys of the Galaxy with arcminute scale angular resolution at 1.4 GHz and below. Over the past few years initial synthesis surveys have been made. More ambitious surveys that combined sensitive continuum observations with full polarimetry and images of the 3-dimensional structure of atomic hydrogen gas at pc scales are currently underway in the northern (DRAO) and southern (ATNF) hemispheres. The interstellar medium of the Galaxy contains structure on all spatial scales, and these surveys combined data from aperture synthesis telescopes and signal dish antennas to provide full spatial frequency coverage to the resolution limit. Preliminary results reveal wide-spread features and processes in the the interstellar medium that are not readily visible by other means, including, for example, unusual atomic hydrogen structures related to the vertical transfer of matter and radiation between the disk and halo of the Galaxy, Faraday rotation structures that allow study of the magnetic field and diffuse ionized component in the plane of the Galaxy, and a cold atomic phase of the neutral medium that may provide a link between global shock phenomena in the galaxy and the formation of molecular clouds.

Type
Part 5: Galactic Surveys and Extended Emission
Information
Symposium - International Astronomical Union , Volume 199: The Universe at Low Radio Frequencies , 2002 , pp. 251 - 258
Copyright
Copyright © Astronomical Society of the Pacific 2002 

References

Braunsfurth, E. 1983, A&A, 117, 297 Google Scholar
Cleary, M.N., Heiles, C. & Haslam, C.G.T. 1979, A&AS, 36, 95 Google Scholar
Dickey, J.M., McClure-Griffiths, N., Gaensler, B., Green, A., Haynes, R. & Wieringa, M. 1999, in ASP Conf. Ser. Vol. 168, New Perspectives on the Interstellar Medium, ed. Taylor, A.R., Landecker, T. & Joncas, G., (San Francisco: ASP), 27 Google Scholar
English, J., Taylor, A.R., Mashchenko, S., Irwin, J., Basu, S. & Johnstone, D. 2000, ApJ, in press Google Scholar
Gibson, S.J., Taylor, A.R., Higgs, L.A. & Dewdney, P.E. 2000, ApJ, in press Google Scholar
Gray, A.D., Landecker, T.L., Dewdney, P.E., Taylor, A.R. 1998, Nature, 383, 660 Google Scholar
Gray, A.D., Landecker, T.L., Dewdney, P.E., Taylor, A.R., Willis, A.G., & Normandeau, M. 1999, ApJ, in press Google Scholar
Green, A.J., Cram, L.E., Large, M.I. & Ye, T. 1999, ApJS, 122, 207 Google Scholar
Haslam, C.G.T., Salter, C.J., Stoffel, H. & Wilson, W.E. 1982, A&AS, 47, 1 Google Scholar
Kallas, E. & Reich, W. 1980, A&AS, 42, 227 Google Scholar
Normandeau, M., Taylor, A.R. & Dewdney, P.E. 1996, Nature, 380, 687 Google Scholar
Reich, W., Furst, E., Steffen, P., Reif, K. & Haslam, C.G.T. 1985, A&AS, 58, 197 Google Scholar
Reich, P., Reich, W. & Furst, E. 1997, A&AS, 126, 413 Google Scholar
Taylor, A.R., Wallace, B.J. & Goss, W.M. 1992, AJ, 103, 931 Google Scholar
Taylor, A.R., Goss, W.M., Coleman, P.H., van Leeuwen, J. & Wallace, B.J. 1997, ApJS, 107, 239 Google Scholar
Wieringa, M.H., de Bruyn, A.G., Jansen, D., Brouw, W.N. & Katgert, P. 1993, A&A, 268, 215 Google Scholar
Weaver, H.F. & Williams, D.R.W. 1973, A&AS, 8, 1 Google Scholar