GS 121-05-037: a new Galactic chimney candidate with signs of triggered star formation.

SUAD LAURA A.; MOLINA LERA, J A; CICHOWOLSKI SILVINA

ASTRONOMY AND ASTROPHYSICS

EDP SCIENCES S A

Lugar: Paris; Año: 2022 vol. 668

0004-6361

Aims. The goal of this study is to analyze the H i supershell GS 121−05−037 and its role in triggering star formation.Methods. To characterize the supershell, we analyzed the H i 21-cm line and the far-infrared emission distributions. In addition, tostudy the star formation processes related to GS 121−05−037, we used the Gaia survey, together with spectroscopic and photometriccalculations, and derived a method to look for massive OB–type stars.Results. The H i characterization of GS 121−05−037 shows an expanding structure centered at (l, b) ∼ (121 ◦ .3, −4 ◦ .8) in the velocityrange from −47.8 to −25.2 km s −1 . It is located at 3.2 ± 1.0 kpc from the Sun and has a kinetic energy of E k = (2.1 ± 1.3) ×10 50 erg. GS 121−05−037 presents, in the H i emission distribution, an open morphology toward the Galactic halo. The analysisof the IR emission reveals the presence of 32 H ii regions seen projected into the borders of GS 121−05−037. A spectroscopic andphotometric analysis to look for the ionizing stars of these regions reveals that 12 of them would be located at a similar distance toGS 121−05−037.Conclusions. The relative location between GS 121−05−037 and the H ii regions, together with their age difference, led us to con-clude that the ionizing stars could have been created due to the expansion of the H i supershell. On the other hand, the H ii regionslocated on the interface of two or more supershells could have originated from the collision of the H i structures. Finally, the openmorphology of GS 121−05−037 toward the halo suggests that this large structure could be a Galactic chimney.