Radio and infrared study of southern H II regions G346.056-0.021 and
  G346.077-0.056
  Aims. We present a multiwavelength study of two southern Galactic H II
regions G346.056-0.021 and G346.077-0.056 which are located at a distance of
10.9 kpc. The distribution of ionized gas, cold and warm dust and the stellar
population associated with the two H II regions are studied in detail using
measurements at near-infrared, mid-infrared, far-infrared, submillimeter and
radio wavelengths.
  Methods. The radio continuum maps at 1280 and 610 MHz were obtained using the
Giant Metrewave Radio Telescope to probe the ionized gas. The dust temperature,
column density and dust emissivity maps were generated by using modified
blackbody fits in the far-infrared wavelength range 160 - 500 {\mu}m. Various
near- and mid-infrared colour and magnitude criteria were adopted to identify
candidate ionizing star(s) and the population of young stellar objects in the
associated field.
  Results. The radio maps reveal the presence diffuse ionized emission
displaying distinct cometary morphologies. The 1280 MHz flux densities
translate to ZAMS spectral types in the range O7.5V - O7V and O8.5V - O8V for
the ionizing stars of G346.056-0.021 and G346.077-0.056, respectively. A few
promising candidate ionizing star(s) are identified using near-infrared
photometric data. The column density map shows the presence of a large, dense
dust clump enveloping G346.077-0.056. The dust temperature map shows peaks
towards the two H II regions. The submillimetre image shows the presence of two
additional clumps one being associated with G346.056-0.021. The masses of the
clumps are estimated to range between {\sim} 1400 to 15250 M{\sun}. Based on
simple analytic calculations and the correlation seen between the ionized gas
distribution and the local density structure, the observed cometary morphology
in the radio maps is better explained invoking the champagne-flow model.
