$\rm H_2CO$ and $\rm H110\alpha$ Observations toward the Aquila
  Molecular Cloud
  The formaldehyde $\rm H_2CO(1_{10} - 1_{11})$ absorption line and
H$110\alpha$ radio recombination line (RRL) have been observed toward the
Aquila Molecular Cloud using the Nanshan 25 m telescope operated by the
Xinjiang Astronomical Observatory CAS. These first observations of the $\rm
H_2CO$ $(1_{10} - 1_{11})$ absorption line determine the extent of the
molecular regions that are affected by the ongoing star formation in the Aquila
molecular complex and show some of the dynamic properties. The distribution of
the excitation temperature $T_{ex}$ for $\rm H_2CO$ identifies the two known
star formation regions W40 and Serpens South as well as a smaller new region
Serpens 3. The intensity and velocity distributions of $\rm H_2CO$ and $\rm
^{13}CO(1-0)$ do not agree well with each other, which confirms that the $\rm
H_2CO$ absorption structure is mostly determined by the excitation of the
molecules resulting from the star formation rather than by the availability of
molecular material as represented by the distribution. Some velocity-coherent
linear $\rm ^{13}CO(1-0)$ structures have been identified in velocity channel
maps of $\rm H_2CO$ and it is found that the three star formation regions lie
on the intersect points of filaments. The $\rm H110\alpha$ emission is found
only at the location of the W40 H II region and spectral profile indicates a
redshifted spherical outflow structure in the outskirts of the H II region.
Sensitive mapping of $\rm H_2CO$ absorption of the Aquila Complex has correctly
identified the locations of star-formation activity in complex molecular clouds
and the spectral profiles reveal the dominant velocity components and may
identify the presence of outflows.
