IGRINS Near-IR High-Resolution Spectroscopy of Multiple Jets around LkHα 234

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We present the results of high-resolution near-IR spectroscopy toward the multiple outflows around the Herbig Be star Lk 234 using the Immersion Grating Infrared Spectrograph (IGRINS). Previous studies indicate that the region around Lk 234 is complex, with several embedded YSOs and the outflows associated with them. In simultaneous H- and K-band spectra from HH 167, we detected 5 and 14 H₂ emission lines. We revealed a new jet driven by radio continuum source VLA 3B. Position-velocity diagrams of H₂ 1-0 S(1) λ2.122 µm line show multiple velocity peaks. The kinematics may be explained by a geometrical bow shock model. We detected a component of H₂ emission at the systemic velocity (VLSR = -10.2) along the whole slit in all slit positions, which may arise from the ambient photodissociation region. Low-velocity gas dominates the molecular hydrogen emission from knots A and B in HH 167, which is close to the systemic velocity, emission lines are detected at farther from the systemic velocity, at VLSR = -100 - -130. We infer that the H₂ emission arises from shocked gas entrained by a high-velocity outflow. Population diagrams of H₂ lines imply that the gas is thermalized at a temperature of 2,500 - 3,000 K and the emission results from shock excitation.