Interferometric studies of 3 millimeter continuum and molecular lines in the giant molecular cloud Sagittarius B2

The giant molecular cloud Sagittarius B2 is known for its active role in chemical evolution, massive star formation, and complex kinematic structure. Studies of the 3 mm continuum and the transitions of various molecular species are essential in understanding not only the chemical evolution but also the physical and kinematic structure of the Sgr B2 cloud. In this study, the high-resolution full synthesis observations of HNO, CCS and HC$\sp{13}$CCN, and BIMA array observations of C$\sp{18}$O, OCS, HNCO, NH$\sb2$CHO, and HCOOCH$\sb3$ in the Sgr B2 cloud are presented. By utilizing the distinct physical and chemical characteristics of different molecular transitions of various species, we were able to study the physical and chemical properties of the Sgr B2 cloud. In total, 13 transitions of 8 different molecules were observed. In addition, 3-mm continuum emission at 78.5, 81.5, 84.9, 87.9, 106.9 and 109.9 GHz was also observed. Our studies are essential for understanding the behavior of nitrogen-bearing molecules and are important for establishing observational constraints for the astrochemical models involving nitrogen compounds. Our data also support the existence of core-mantle grains and demonstrate their close relationship with the formation of large complex molecules.U of I OnlyETDs are only available to UIUC Users without author permissio