could be the result of a noise fluctuation, or perhaps a faint and unrelated background source.

![image](fig3.eps)

\[fig:vla\]

Line Emission {#sec:line}
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Emission from the $^{12}$CO and $^{13}$CO J=2-1 lines were clearly detected by the SMA observations over the narrow $v_{\rm LSR}$ range $-6$ to $-4$ km s$^{-1}$, close to the stellar velocity of $-4.6$ km s$^{-1}$ in this reference frame. Single dish observations of the $^{12}$CO J=3-2 line with a $15''$ beam show extended emission, concentrated in a filament that extends from the north-northeast of HR 8799 to the south-southwest, most likely affiliated with the nearby MBM 53-55 complex of high latitude clouds [@williams06; @su09]. The submillimeter dust continuum emission observed by [*Herschel*]{} also shows traces of this large scale feature [@matthews14]. Like previous attempts to use interferometers to image the molecular emission in this region, the extended structure evident in lower angular resolution single dish maps [@su09] remains poorly sampled and highly problematic to reconstruct, even with the lower spatial frequency information newly obtained with the SMA. Regardless of the choice of visibility weighting scheme and [clean]{} deconvolution parameters, all of our attempts at imaging the line emission show pronounced artifacts. Emission from the $^{13}$CO J=2-1 line, with 