부산대학교 도서관

Over the past few years, chemical studies have revealed multiple structures in the vicinity of young stellar objects (YSOs). It has become evident that specific physical conditions are associated with the emission of particular molecular lines, allowing us to use molecular probes of the YSO physics. Consequently, chemical surveys are now necessary to fully constrain the origin of the observed structures. Several surveys have been conducted to explore the chemistry of YSOs, focusing on Class 0 and Class II objects. However, our knowledge of intermediate objects, that are Class I objects, remains limited. To bridge the gap and establish the relationship between observed structures and molecular line emission at the Class I evolutionary stage, we investigate the spatial distribution of key molecular gas species in the low-mass Class I protostar L1489 IRS (IRAS 04016+2610), a source part of the ChemYSO survey. We performed a 3mm line survey at high spatial and high spectral resolution using the NOEMA interferometer and the IRAM-30m telescope. We present here the ten brightest lines of our survey, in which we identified a new ~ 3 000 au long streamer in HC3N, C2H, and c-C3H2 emission, likely associated with more localized accretion shocks probed in SO. In addition, two ~ 10 000 au bubbles are seen with the dense molecular tracers HCO+, CS, and HCN around the YSO. Additionally, potential indicators of a second outflow appear in CS and HCN emission, but its nature remains to be confirmed. The late infall identified at large scales may originate from the nearby prestellar core L1489 and is likely responsible for the formation of an external warped disk in this system. The detection of a potential second outflow could be the direct evidence of a binary system. Finally, we hypothesize that the bubbles may result from the magnetic pressure as observed in numerical simulations.
Comment: 16 pages, 12 figures, accepted for publication in Astronomy & Astrophysics