Searching for the HH 31 counter-jet in the protostar IRAS 04248+2612 A combination of NIR and sub-mm wavelengths

L. FERRERO; E. ARTUR DEL LA VILLARMOIS; M. GOMEZ

Salta

Congreso; Science with LLAMA; 2022

During the initial stages of the stellar collapse (the class 0 and I phases with ages of ∼ 10^4 − 10^5 yr), the incipient star begins to eject winds along the rotation axis. These winds alleviate the angular momentum accumulation, help to stop the collapse and give rise to the jets and/or Herbig-Haro (HH) objects detected in the optical. Although most jets are straight or collimated, a small fraction has curved shapes. Different mechanisms can produce the non-straight jets, binarity or multiplicity of the driving source being one of them. This work shows preliminary results on the study of the sinusoidal HH 31 jet and its driving source, the low-mass Class I protostar IRAS 04248+2612, located in the Taurus-Auriga star-forming region. Other authors have detected the binarity of the central source, where the separation between the components is of 0.16′′(∼ 24 AU, at a distance of 140 pc), and identified a dark lane perpendicular to the jet, which could be related to an edge-on disk, but no further analysis has been done. Furthermore, only the jet has been detected, while the counter-jet could be embedded or hidden by the cloud extinction in the near infrared. In this contribution, we report progress on the analysis of multiple molecular transition line data obtained with the SMA array. We also analyse Gemini NIRI 2.12 μm H2 line and K-band images. The molecular transitions are used to reveal the physical conditions of the envelope and outflow cavity at the highest angular resolution observed so far. NIRI images are employed to search for the counter-jet. The aim of this work is to investigate the likely cause–effect relation between the S-shape morphology and the central star and circumstellar disk properties.