High-Resolution ALMA Observations Reveal Complex Structure in HH46/47 Protostellar System
Astronomers using the ALMA telescope obtained detailed 0.1-arcsecond resolution observations of the HH46/47 system, revealing a compact protostar surrounded by a circumbinary disk with substructures and a complex molecular outflow. The observations trace multiple molecular species across the envelope-disk system and show that the outflow expands radially through an entrainment mechanism rather than originating directly from a disk wind. These findings provide insights into how young binary star systems form and how protostellar outflows are launched and evolve.
Researchers presented new ALMA millimeter-wavelength observations of the HH46/47 molecular outflow system at 0.1-arcsecond resolution, revealing unprecedented detail in this nearby protostellar region. The 1.3 mm continuum data show a compact central source with a circumbinary disk displaying substructures, while the companion star appears as a local intensity minimum in the millimeter continuum despite being detected in optical and infrared observations. Multiple molecular tracers—including C18O, SO, H2CO, and CH3OH—map the envelope-disk system, with different species probing distinct regions from the extended envelope to compact structures near the centrifugal barrier. The observations are consistent with a rotating-infalling envelope transitioning to an inner disk at approximately 30 AU around a 0.3 solar-mass protostar. Analysis of the outflow using multiple CO isotopologues reveals shell structures and three-dimensional velocity fields, with results suggesting the outflow expands radially through entrainment rather than being launched directly from a disk wind.
What different sources said
- arXiv astro-phCenter
ALMA High-resolution Observation of the HH46/47 Outflow/disk/envelope System
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