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Volume 50 Supplement 6-7

Special Issue: The Zodiacal Cloud Sciences

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Disentangling the main populations of the Zodiacal Cloud from Zodiacal Light observations

Abstract

Photometric surveys of the Zodiacal Light (ZL) already allowed to retrieve features of interplanetary dust space distribution and optical behaviour. Of the brightness “gathering” function dZ = D(α)/m along each line of sight (LOS), (α being the phase angle, m the subsolar distance of the LOS, D) the local scattering coefficient), two approximate values could be derived, based on the constraints provided by the two observed values of its integral Z, when the LOS is in-ecliptic. This “nodes of lesser uncertainty” method (Dumont, Levasseur-Regourd, Renard, 1985 to 1996), however, lowered but did not rule out question marks upon the phase function.

To improve this inversion, additional constraints can be found in ZL surveys from deep space probes. We show that both the Pioneer 10 (Toller and Weinberg, 1985) and (despite their lack of in-ecliptic scans) the Helios (Leinert et al., 1982) data imply the phase function to weakly depart from isotropy, at least in the 30°–150° range.

The latitudinal dependence f, r = cst) of the space density (less well known than the heliocentric, D(r, β = 0)) can be tracked through the brightness ratio, at the same elongation ε, aiming in the helioecliptic meridian, against in the ecliptic. At ε = 90°, this ratio 0.3 would lead—in the improper assumption of a single, homogeneous cloud—to fit the latitudinal density drop by a — cos12β function. The resulting brightness ratio at ε < 90°, which should be equal to ∫LOS cos12 β(α)D(α)· dα/∫LOS D(α)dα turns out to be much lower than the ratio observed in the 60° > ε > 15° range (again 0.3). This contradiction is solved with a steeper exponent (20–22?) for cos/gb, and by assuming the flattened cloud to coexist with another one, spherically symmetrical, which contributes 15–25 S10 at ε = 90°, 50–80 S10 at ε = 60°, 100–160 S10 at ε = 45° and 250–450 S10 at ε = 30°.

References

  • Dumont, R., Phase function and polarization curve of interplanetary scatterers from zodiacal light photopolarimetry, Planet. Space Sci., 21, 2149–2155, 1973.

    Article  Google Scholar 

  • Dumont, R. and A. C. Levasseur-Regourd, Zodiacal Light gathered along the line of sight: Retrieval of the local scattering coefficient from photometric surveys of the ecliptic plane, Planet. Space Sci., 33, 1–9, 1985.

    Article  Google Scholar 

  • Dumont, R. and A. C. Levasseur-Regourd, Properties of interplanetary dust from infrared and optical observations: I. Temperature, global volume intensity, albedo and their heliocentric gradients, Astron. Astrophys., 191, 154–160, 1988.

    Google Scholar 

  • Dumont, R. and F. Sanchez, Zodiacal Light photopolarimetry, III. Allsky survey from Teide 1964–1975 with emphasis on off-ecliptic features, Astron. Astrophys., 51, 393–399, 1

    Google Scholar 

  • Frey, A., W. Hofmann, D. Lemke, and C. Thum, Photometry of the Zodiacal Light with the Balloon-borne telescope THISBE, Astron. Astrophys., 36, 447–454, 1974.

    Google Scholar 

  • Giese, R. H. and B. Kneißel, Three-dimensional models of the zodiacal dust cloud, II. Compatibility of proposed infrared models, Icarus, 81, 369–378, 1989.

    Article  Google Scholar 

  • Giese, R. H., B. Kneißel, and U. Rittich, Three-dimensional models of the zodiacal dust cloud, a comparative study, Icarus, 68, 395–411, 1986.

    Article  Google Scholar 

  • Leinert, Ch. and E. Grün, Interplanetary dust, in Physics of the Inner Heliosphere I, edited by R. Schwenn and E. Marsch, pp. 207–275, 1990.

  • Leinert, Ch., H. Link, E. Pitz, and R. H. Giese, Interpretation of a rocket photometry of the inner Zodiacal Light, Astron. Astrophys., 47, 221–230, 1976.

    Google Scholar 

  • Leinert, Ch., I. Richter, E. Pitz, and M. Hanner, HELIOS Zodiacal Light measurements—a tabulated summary, Astron. Astrophys., 110, 355–357, 1982.

    Google Scholar 

  • Levasseur-Regourd, A. C. and R. Dumont, Sur l’isotropie de la fonction de phase dans la diffusion par les particules interplanétaires, C.R.A.S. Paris, 286, B–61–B–64, 1978.

    Google Scholar 

  • Levasseur-Regourd, A. C. and R. Dumont, Absolute photometry of the Zodiacal Light, Astron. Astrophys., 84, 277–279, 1980.

    Google Scholar 

  • Renard, J. B., Mise en évidence de l’évolution des propriétés optiques et physiques des grains dans le système solaire, Thesis, Univ. Paris VI, 1992.

  • Renard, J. B., A. C. Levasseur-Regourd, and R. Dumont, Properties of interplanetary dust from infrared and optical observations, II. Brightness, polarization, temperature, albedo and their dependence on the elevation above the ecliptic, Astron. Astrophys., 304, 602–608, 1995.

    Google Scholar 

  • Sparrow, J. G. and E. P. Ney, Observations of the Zodiacal Light from the ecliptic to the poles, Astrophys. J., 174, 705–716, 1972.

    Article  Google Scholar 

  • Toller, G. N. and J. L. Weinberg, The change in near-ecliptic Zodiacal Light brightness with heliocentric distance, in ASSL, 119, edited by R. H. Giese and Ph. Lamy, pp. 21–25, 1985.

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Dumont, R., Renard, J.B., Levasseur-Regourd, A.C. et al. Disentangling the main populations of the Zodiacal Cloud from Zodiacal Light observations. Earth Planet Sp 50, 473–476 (1998). https://doi.org/10.1186/BF03352136

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  • DOI: https://doi.org/10.1186/BF03352136

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