A 16 au Binary in the Class 0 Protostar L1157 MMS

Abstract

We present VLA observations toward the Class 0 protostar L1157 MMS at 6.8 mm and 9 mm with a resolution of ~0.04" (14 au). We detect two sources within L1157 MMS and interpret these sources as a binary protostar with a separation of ~16 au. The material directly surrounding the binary system within the inner 50 au radius of the system has an estimated mass of 0.11 M_sun, calculated from the observed dust emission. We interpret the observed binary system in the context of previous observations of its flattened envelope structure, low rates of envelope rotation from 5000 to 200 au scales, and an ordered, poloidal magnetic field aligned with the outflow. Thus, L1157 MMS is a prototype system for magnetically-regulated collapse and the presence of a compact binary within L1157 MMS demonstrates that multiple star formation can still occur within envelopes that likely have dynamically important magnetic fields.

21 pages, 6 figures, 4 tables, accepted to ApJ

References in corpus (12)

• Magnetic Fields in the Formation of Sun-Like Stars
• The VLA/ALMA Nascent Disk and Multiplicity (VANDAM) Survey of Orion Protostars. A Statistical Characterization of Class 0 and I Protostellar Disks
• A Large Catalog of Accurate Distances to Local Molecular Clouds: The Gaia DR2 Edition
• Decoupling of Magnetic Fields in Collapsing Protostellar Envelopes and Disk Formation and Fragmentation
• Close companions around young stars
• A Flattened Protostellar Envelope in Absorption around L1157
• Gas flow and accretion via spiral streamers and circumstellar disks in a young binary protostar
• First image of the L1157 molecular jet by the CALYPSO IRAM-PdBI survey
• The Formation and Evolution of Wide-Orbit Stellar Multiples In Magnetized Clouds
• Orbital and mass constraints of the young binary system IRAS 16293-2422 A
• Formation and evolution of protostellar accretion discs. II. From 3D simulation to a simple semi-analytic model of Class 0/I discs
• On the nature of the compact sources in IRAS 16293-2422 seen in at centimeter to sub-millimeter wavelengths