Feedback From Massive Stars To Interstellar Medium:A Comparative Study Of S183 And S187

The intense feedback from massive stars profoundly affects the interstellar medium around them and may trigger the formation of the next generation of stars.S183 and S187 are two massive star formation regions located in the second quadrant of the Milky Way,showing different trigger star formation patterns.The distance of S183 is 5.48±0.84 kpc,and the distance of S187 is about 1 kpc.Based on the data of ¹²CO/¹³CO/C¹⁸0（J=1-0）from the Milky Way Imaging Scroll Painting（MWISP）survey,we studied the basic properties of the molecular clouds in the S187 and S183 regions,and explored the feedback of massive stars on the molecular clouds.Using GaussPy+algorithm and ACORNS algorithm,32 molecular clouds were identified in S187 region,and the distance of 8 clouds was measured by combining with the star extinction data of Gaia DR3 G band.The content of relatively dense gas traced by ¹³CO and C¹⁸O in S187 region is 1-2 orders of magnitude higher than the molecular cloud in the galactic plane l～[129.75°,140.25°],b～[-5.25°,+5.25°]region.The average column density of the molecular cloud in the S183 region is only 0.89 × 10²¹ cm^-2,while the column density of the head of cometary cloud near the HII region S183 can reach～10²² cm^-2.In the S187 region,243 ¹³CO and 98 C¹⁸0 clumps were identified,among which 7 ¹³CO and 5 C¹⁸Oclumps had the potential to form massive stars.In the S183 molecular cloud,195 ¹³CO clumps have been identified,among which 4 ¹³CO clumps have the potential to form massive stars.Both S187 parent shell and the HII region S187 showed expansion motion,and the cometary cloud in S183 region showed obvious velocity gradient on the PV diagrams.The results show that the feedback of massive stars plays a significant role in the aggregation of molecular clouds around them,providing conditions for the formation of the next generation of massive stars.