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

SUAD, L.A.; MOLINA LERA, J.A.; CICHOWOLSKI, S.

ASTRONOMY AND ASTROPHYSICS

EDP SCIENCES S A

Año: 2022

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, to study the star formation processes related to GS 121−05−037 we used the Gaia survey together with spectroscopic/photometric calculations 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 velocity range 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 Ek = (2.1 ± 1.3) × 1050 erg. GS 121−05−037 presents, in the H i emission distribution, an open morphology towards the Galactic halo. The analysis of the IR emission reveals the presence of 32 H ii regions seen projected into the borders of GS 121−05−037. A spectroscopic/photometric analysis to look for the ionizing stars of these regions reveals that 12 of them would be located at a similar distance to GS 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 conclude that the ionizing stars could have been created due to the expansion of the H i supershell. On the other hand, the H ii regions located on the interface of two or more supershells could have been originated from the collision of the H i structures. Finally, the open morphology of GS 121−05−037 towards the halo suggests that this large structure could be a Galactic chimney.