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Polarized Infrared Emission from Dust

Published online by Cambridge University Press:  23 September 2016

Roger H. Hildebrand*
Affiliation:
The University of Chicago

Extract

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At the beginning of this decade what we knew about polarization of far-infrared emission from dense clouds was that some very good observers had looked for it and had not found it. Gull et al. (1978) had shown that the degree of polarization in Orion was not more than 2%. That information provided an important guide but very little encouragement for later efforts. There was reason to doubt whether the mechanisms invoked to explain the alignment of dust grains in the diffuse intercloud medium would operate in dense clouds; whether the strengths of the magnetic fields in dense clouds would be sufficiently greater than those in the intercloud medium to overcome the higher rate at which gas collisions would destroy alignment; and whether the field, if sufficient locally, would have enough large-scale order to give measurable polarization in far-infrared observations with large beams and large column depths.

Type
Section III: Dust in Dense Clouds
Copyright
Copyright © Kluwer 1989 

References

Aitken, D. K., Roche, P. F., Bailey, J. A., Briggs, G. P., Hough, J. H., and Thomas, J. A. 1986, M. N. R. A. S., 218, 363.CrossRefGoogle Scholar
Chandrasekhar, S., and Fermi, E. 1953, Ap. J., 118, 113.CrossRefGoogle Scholar
Cudlip, W., Furniss, I., King, K. J., and Jennings, R. E. 1982, M. N. R. A. S., 200, 1169.CrossRefGoogle Scholar
Davidson, J. A., Harvey, P. M., Lester, D. F., Morris, M., and Werner, M. W. 1988, in preparation.Google Scholar
Davis, L. Jr., 1951, Phys. Rev., 81, 890.CrossRefGoogle Scholar
Davis, L. Jr., and Greenstein, J. L. 1951, Ap. J., 114, 206.CrossRefGoogle Scholar
Dragovan, M. 1986, Ap. J., 308, 270.CrossRefGoogle Scholar
Erickson, N. R., Goldsmith, P. F., Snell, R. L., Berson, R. L., Huguenin, G. R., Ulrich, B. L., and Lada, C. J. 1982, Ap. J., 261, L103.CrossRefGoogle Scholar
Gold, T. 1952, M. N. R. A. S., 112, 215.CrossRefGoogle Scholar
Gull, G. E., Russell, R. W., Melnick, G., and Harwit, M. 1980, Ap. J., 85, 1379.Google Scholar
Harwit, M. 1970, Nature, 226, 61.CrossRefGoogle Scholar
Hildebrand, R. H., Dragovan, M., and Novak, G. 1984, Ap. J., 284, L51.CrossRefGoogle Scholar
Hildebrand, R. H. 1987, Astro. Lett. and Communications, 26, 263.Google Scholar
Hildebrand, R. H. 1988, Quart. J. R. A. S., in press.Google Scholar
Hildebrand, R. H., Davidson, J. A., Gonatas, D., Novak, G., Platt, S. R., and Wu, X. 1988. The Sgr A results presented here will be incorporated in a later publication (see also Werner, et al., 1988).Google Scholar
Keene, J., Hildebrand, R. H., and Whitcomb, S. E. 1982, Ap. J., 252, L11.CrossRefGoogle Scholar
Mouschovias, T. Ch. 1987, in Physical Processes in Interstellar Clouds, eds. Morfill, G. E. and Scholer, M. D. (Boston: Reidel), p. 455.Google Scholar
Novak, G. 1988, , .Google Scholar
Novak, G., Dragovan, M., Gonatas, D., Hildebrand, R. H., and Platt, S. R. 1988. (Submitted to Ap. J.).Google Scholar
Purcell, E. M. 1979, Ap. J., 231, 404.CrossRefGoogle Scholar
Smith, C. H., Roche, P. F., and Aitken, D. K. 1988, in preparation. (See also Aitken, et al., 1986.)Google Scholar
Spitzer, L. (Jr.), and Tukey, J. W. 1951, Ap. J., 114, 187.CrossRefGoogle Scholar
Troland, T. H., and Heilas, C. 1986, Ap. J., 301, 339.CrossRefGoogle Scholar
Werner, M. W., Davidson, J. A., Hildebrand, R. H., Morris, M. R., Novak, G., and Platt, S. R. 1988, Ap. J., in press.Google Scholar