Hostname: page-component-78c5997874-s2hrs Total loading time: 0 Render date: 2024-11-19T05:49:32.809Z Has data issue: false hasContentIssue false

Galactic structure and turbulence, pulsar distances, and the intergalactic medium

Published online by Cambridge University Press:  20 March 2013

J. M. Cordes*
Affiliation:
Astronomy Department, Cornell University email: [email protected]
Rights & Permissions [Opens in a new window]

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.

This paper summarizes how multi-wavelength measurements will be aggregated to determine Galactic structure in the interstellar medium (ISM) and produce the next-generation electron density model. Fluctuations in density and magnetic field from parsec scales down to about 1000 km cause a number of propagation effects in both radio waves and cosmic rays. Density microstructure appears to include Kolmogorov-like turbulence. The next generation electron-density model, NE2012, will include about double the number of lines of sight with dispersion and scattering measurements and it will be anchored with a much larger number of pulsar parallax distances. The foreground Galactic model is crucial for inferring similar ionized structures in the intergalactic medium (IGM) from scattering measurements on high-z objects. Intergalactic scattering is discussed with reference to distant sources of radio bursts. In particular, the cosmological radio scattering horizon is defined along with its analog for the ISM.

Type
Contributed Papers
Copyright
Copyright © International Astronomical Union 2013

References

Berkhuijsen, E. M., Mitra, D., & Mueller, P. 2006, Astronomische Nachrichten, 327, 82Google Scholar
Bignall, H., Jauncey, D. L., Kedziora-Chudczer, L., et al. 2009, Approaching Micro-Arcsecond Resolution with VSOP-2: Astrophysics and Technologies, 402, 256Google Scholar
Chatterjee, S., Brisken, W. F., Vlemmings, W. H. T., et al. 2009, ApJ, 698, 250CrossRefGoogle Scholar
Churchwell, E., Babler, B. L., Meade, M. R., et al. 2009, PASP, 121, 213Google Scholar
Cordes, J. M., Weisberg, J. M., Frail, D. A., Spangler, S. R., & Ryan, M. 1991, Nature, 354, 121CrossRefGoogle Scholar
Cordes, J. M. & Lazio, T. J. W. 2002, arXiv:astro-ph/0207156Google Scholar
Gaensler, B. M., Madsen, G. J., Chatterjee, S., & Mao, S. A. 2008, Publications of the Astronomical Society of Australia, 25, 184Google Scholar
Gómez, G. C., Benjamin, R. A., & Cox, D. P. 2001, AJ, 122, 908Google Scholar
Hou, L. G., Han, J. L., & Shi, W. B. 2009, AAP, 499, 473Google Scholar
Kramer, M., Bell, J. F., Manchester, R. N., et al. 2003, MNRAS, 342, 1299Google Scholar
Manchester, R. N., Hobbs, G. B., Teoh, A., & Hobbs, M., 2005, Astron. J., 129, 1993CrossRefGoogle Scholar
Lorimer, D. R., Faulkner, A. J., Lyne, A. G., et al. 2006, MNRAS, 372, 777Google Scholar
Sanna, A., Reid, M. J., Moscadelli, L., et al. 2009, ApJ, 706, 464CrossRefGoogle Scholar
Stinebring, D. R., McLaughlin, M. A., Cordes, J. M., et al. 2001, ApJL, 549, L97CrossRefGoogle Scholar
Taylor, J. H. & Cordes, J. M. 1993, ApJ, 411, 674Google Scholar