Revisiting G29.862–0.0044: A jet cavity disrupted by an outflow in a likely young stellar object wide binary system

¹ CONICET – Universidad de Buenos Aires. Instituto de Astronomía y Física del Espacio CC 67, Suc. 28, 1428 Buenos Aires, Argentina
² Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Física. Buenos Aires, Argentina
³ Observatorio Astronómico, Universidad Nacional de Córdoba, Laprida 854, X5000BGR Córdoba, Argentina
⁴ Isaac Newton Group of Telescopes, E38700 La Palma, Spain
⁵ Instituto de Astrofísica de Canarias (IAC) and Universidad de La Laguna, Dpto. Astrofísica, Spain

^★ Corresponding author: sparon@iafe.uba.ar

Received: 28 May 2025
Accepted: 13 August 2025

Abstract

Aims. A few years ago, we investigated the massive young stellar object (MYSO) G29.862–0.0044 (YSO-G29), an intriguing star-forming region at a distance of 6.2 kpc. Although the typical disc-jet scenario was proposed to explain the observations, it remained far from conclusive. We wonder if the puzzling observed near-IR features are produced by only one source or if it is due to confusion generated by an unresolved system of YSOs. Unveiling this issue is important for a better understanding of the star-forming processes.

Methods. We analysed YSO-G29 using new observations in the near-IR from Gemini-NIFS, at the radio continuum (10 GHz) from the Jansky Very Large Array (JVLA) and new continuum (1.3 mm) and molecular line data from the Atacama Large Millimeter Array (ALMA).

Results. The near-IR observations allowed us to detect emission of H₂ 1−0 S(1) and Brγ lines in YSO-G29, which are compatible with excitation and ionisation from UV radiation propagating in a highly perturbed ambient. In addition, we also found some evidence of H₂ excitation by collisions. The ALMA data show the presence of a conspicuous and collimated molecular outflow propagating southwards, while to the north, an extended molecular feature perfectly surrounded by the Ks near-IR emission appears. The continuum emission at 1.3 mm allowed us to better resolve the molecular cores, one of which stands out due to its high temperatures and rich chemical composition. From the JVLA observations, we discovered a compact radio continuum source, a likely compact HII region or an ionised jet of a massive protostar, located at ~0.″7 (~0.02 pc) from the main millimetre core. In this way, we propose a YSO wide binary system.

Conclusions. We can explain the nature of the intriguing near-IR features previously observed: Cone-like structures produced by jets or winds of one of the components of the binary system that cleared out the surroundings were disrupted by a molecular outflow probably from the other component. These results complete the picture of what is happening in YSO-G29 and reveal a phenomenon that should be considered when investigating massive star-forming regions.