Observations of Free-Free and Anomalous Microwave Emission from LDN 1622
  with the 100 m Green Bank Telescope
  LDN 1622 has previously been identified as a possible strong source of
dust-correlated Anomalous Microwave Emission (AME). Previous observations were
limited by resolution meaning that the radio emission could not be compared
with current generation high-resolution infrared data from Herschel, Spitzer or
WISE. This Paper presents arcminute resolution mapping observations of LDN 1622
at 4.85 GHz and 13.7 GHz using the 100 m Robert C. Byrd Green Bank Telescope.
The 4.85 GHz map reveals a corona of free-free emission enclosing LDN 1622 that
traces the photo-dissociation region of the cloud. The brightest peaks of the
4.85 GHz map are found to be within 10% agreement with the expected free-free
predicted by SHASSA H{\alpha} data of LDN 1622. At 13.7 GHz the AME flux
density was found to be 7.0 $\pm$ 1.4 mJy and evidence is presented for a
rising spectrum between 13.7 GHz and 31 GHz. The spinning dust model of AME is
found to naturally account for the flux seen at 13.7 GHz. Correlations between
the diffuse 13.7 GHz emission and the diffuse mid-infrared emission are used to
further demonstrate that the emission originating from LDN 1622 at 13.7 GHz is
described by the spinning dust model.
