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The environment of S187, a nearby H ii region (1.4 ± 0.3 kpc), is analyzed. A surrounding shell has been studied in the H i line, molecular lines, and also in infrared and radio continua. We report the first evidence of a clumpy H i environment in its photodissociation region. A background radio galaxy enables the estimation of the properties of cold atomic gas. The estimated atomic mass fraction of the shell is ∼260 M⊙, the median spin temperature is ∼50 K, the shell size is ∼4 pc with typical wall width around 0.2 pc. The atomic shell consists of ∼100 fragments. The fragment sizes correlate with mass with a power-law index of 2.39–2.50. The S187 shell has a complex kinematical structure, including the expanding quasi-spherical layer, molecular envelope, an atomic sub-bubble inside the shell and two dense cores (S187 SE and S187 NE) at different stages of evolution. The atomic sub-bubble inside the shell is young, contains a Class II young stellar object and OH maser in the centre and the associated YSOs in the walls of the bubble. S187 SE and S187 NE have similar masses (∼1200 and ∼900 M⊙, respectively). S187 SE is embedded into the atomic shell and has a number of associated objects, including high-mass protostars, outflows, maser sources, and other indicators of ongoing star formation. No YSOs inside S187 NE were detected, but indications of compression and heating by the H ii region exist.

Investigating the physical and chemical structure of massive star-forming regions is critical for understanding the formation and early evolution of massive stars. We performed a detailed line survey toward six dense cores, named MM1, MM4, MM6, MM7, MM8, and MM11, in the G9.62+0.19 star-forming region resolved in Atacama Large Millimeter/submillimeter Array (ALMA) band 3 observations. Toward these cores, about 172 transitions have been identified and attributed to 16 species, including organic oxygen-, nitrogen-, and sulphur-bearing molecules and their isotopologues. Four dense cores, MM7, MM8, MM4, and MM11, are line-rich sources. Modelling of these spectral lines reveals that the rotational temperature lies in the range 72–115, 100–163, 102–204, and 84–123 K for MM7, MM8, MM4, and MM11, respectively. The molecular column densities are 1.6 × 1015–9.2 × 1017 cm−2 toward the four cores. The cores MM8 and MM4 show a chemical difference between oxygen- and nitrogen-bearing species, i.e. MM4 is rich in oxygen-bearing molecules, while nitrogen-bearing molecules, especially vibrationally excited HC3N lines, are mainly observed in MM8. The distinct initial temperatures at the accretion phase may lead to this N/O differentiation. Through analysing column densities and spatial distributions of O-bearing complex organic molecules (COMs), we found that C2H5OH and CH3OCH3 might have a common precursor, CH3OH. CH3OCHO and CH3OCH3 are likely chemically linked. In addition, the observed variation in HC3N and HC5N emission may indicate their different formation mechanisms in hot and cold regions.