The ALMA-QUARKS survey: Evidence of a candidate high-mass prestellar core aside a bright-rimmed cloud IRAS 18290-0924

Abstract

Although frequently reported in observations, the definitive confirmation of high-mass prestellar cores has remained elusive, presenting a persistent challenge in star formation studies. Using two-band observational data from the 3 mm ATOMS and 1.3 mm QUARKS surveys, we report a high-mass prestellar core candidate, C2, located on the side of the bright-rimmed cloud IRAS 18290-0924. The C2 core identified from the 3 mm continuum data of the ATOMS survey (∼2″, ∼10,000 au at 5.3 kpc) has a mass ranging from 27 to 68 M⊙ for temperatures 10─22 K within a radius of ∼2800 au. The highest-resolution (∼0 .″ 3, ∼1500 au) observations of this source presented to date from the QUARKS survey reveal no evidence of further fragmentation. Further analysis of a total ∼10 GHz bandwidth of molecular line survey does not find star formation activity (e.g., outflows and ionized gas) associated with the core, with a few molecular lines of cold gas detected only. Additionally, virial analysis indicates the C2 core is gravitationally bound (αvir ∼ 0.1−0.3) and thus could be undergoing collapse toward star formation. These results strongly establish a candidate for a high-mass prestellar core, contributing to the very limited number of such sources known to date.