ALMA Images of the Orion Hot Core at 349 GHz

Abstract

We present ALMA images of the dust and molecular line emission in the Orion Hot Core at 349 GHz. At 0.2" angular resolution the images reveal multiple clumps in an arc ~ 1" east of Orion Source I, the protostar at the center of the Kleinmann-Low Nebula, and another chain of peaks from IRc7 towards the southwest. The molecular line images show narrow filamentary structures at velocities > 10 km/s away from the heavily resolved ambient cloud velocity ~5 km/s. Many of these filaments trace the SiO outflow from Source I, and lie along the edges of the dust emission. Molecular line emission at excitation temperatures 300--2000 K, and velocities > 10 km/s from the ambient cloud, suggest that the Hot Core may be heated in shocks by the outflow from Source I or from the BN/Source I explosion. The spectral line observations also reveal a remarkable molecular ring, ~ 2" south of Source I, with a diameter ~ 600 AU. The ring is seen in high excitation transitions of HC3N, HCN v2=1, and SO2. An impact of ejecta from the BN/Source I explosion with a dense dust clump could result in the observed ring of shocked material.

6 pages, 4 figures

References in corpus (6)

• The distance to the Orion Nebula
• Monitoring the Large Proper Motions of Radio Sources in the Orion BN/KL Region
• The ALMA View of the OMC1 Explosion in Orion
• ALMA Observations of Orion Source I at 350 and 660 GHz
• ALMA Imaging of Millimeter/Submillimeter Continuum Emission in Orion KL
• ALMA band 8 continuum emission from Orion Source I

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• The First Mid-Infrared Detection of HNC in the Interstellar Medium: Probing the Extreme Environment Towards the Orion Hot Core
• The complexity of Orion: an ALMA view III. The explosion impact
• The mid-infrared molecular inventory towards Orion IRc2
• Observations of Orion Source I Disk and Outflow Interface
• Magnetic Field Structure of Orion Source I
• Observational evidence for rotational desorption of Complex Molecules by radiative torques from Orion BN/KL
• Mapping physical parameters in Orion KL at high spatial resolution
• Unmasking the physical information inherent to interstellar spectral line profiles with Machine Learning. I. Application of LTE to HCN and HNC transitions
• Molecular Formation in Low-Metallicity Hot Cores