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Imprint of distortions in the Oort Cloud on the CMB anisotropies

Babich, Daniel and Loeb, Abraham (2009) Imprint of distortions in the Oort Cloud on the CMB anisotropies. New Astronomy, 14 (2). pp. 166-179. ISSN 1384-1076.

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We study the effect of a close encounter of a passing star on the shape of the inner Oort Cloud, using the impulse approximation. The deviation of the perturbed Oort Cloud from sphericity adds angular fluctuations to the brightness of the cosmic microwave background (CMB) due to thermal emission by the comets. An encounter with a solar-mass star at an impact parameter of 2100AU, as expected based on the abundance and velocity dispersion of stars in the solar neighborhood, leads to a quadrupole moment C-2 = 4.5(3.5) x 10^(-15) 6.7(1.1) x 10^(-12), 1.1 (0.11) x 10^(-9) at v = 30, 353, 545 GHz, respectively in intensity and (temperature) fluctuations. We also quantify the quadrupole spectral distortions produced by the Scattered Disc, which will exist irregardless of any perturbation and the subsequent shape of the Oort Cloud. For comparison, the temperature fluctuation quadrupole moment predicted by the current cosmological model is C-2 = 1.76 x 10^(-10), which corresponds to fluctuation in the CMB intensity of C-2 = 2.9 x 10^(-10), 6.8 x 10^(-9), 1.6 x 10^(-8) at v = 30, 353, 545 GHz. Finally, we discuss how a measurement of the anisotropic spectral distortions could be used to constrain the trajectory of the closest stellar fly-by.

Item Type:Article
Related URLs:
URLURL TypeDescription
Loeb, Abraham0000-0003-4330-287X
Group:Moore Center for Theoretical Cosmology and Physics
Funding AgencyGrant Number
Betty and Gordon Moore FoundationUNSPECIFIED
Subject Keywords:Cosmic microwave background; Oort Cloud 96.50.Hp; 98.70.Vc
Issue or Number:2
Record Number:CaltechAUTHORS:BABna09
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Official Citation:Copyright © 2008 Elsevier. Received 28 May 2008; revised 9 July 2008; accepted 23 July 2008. Communicated by J. Silk. Available online 3 August 2008. We would like to thank M. Brown, P. Goldreich, M. Holman, Z. Lienhardt and P. Weissman for helpful conversations and L. Dones for sharing an unpublished manuscript. DB thanks the hospitality of the Harvard Institute for Theory and Computation where some of this work was completed and acknowledges financial support from the Betty and Gordon Moore Foundation.
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:12532
Deposited By: Archive Administrator
Deposited On:16 Dec 2008 00:15
Last Modified:09 Mar 2020 13:19

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