* Astronomy

Title: A Limit on the Polarised Anomalous Microwave Emission of Lynds 1622
Authors: B.S. Mason, T. Robishaw, C. Heiles, D. Finkbeiner, C. Dickinson

The dark cloud Lynds 1622 is one of a few specific sites in the Galaxy where, relative to observed free-free and vibrational dust emission, there is a clear excess of microwave emission. In order to constrain models for this microwave emission, and to better establish the contribution which it might make to ongoing and near-future microwave background polarisation experiments, we have used the Green Bank Telescope to search for linear polarisation at 9.65 Ghz towards Lynds 1622. We place a 95.4%upper limit of 88 micro-Kelvin (123 micro-Kelvin at 99.7 confidence) on the total linear polarisation of this source averaged over a 1'.3 FWHM beam. Relative to the observed level of anomalous emission in Stokes I these limits correspond to fractional linear polarisations of 3.2% and 4.1%.

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