On the nature of the compact sources in IRAS 16293-2422 seen in at centimeter to sub-millimeter wavelengths

Abstract

We present multi-epoch continuum observations of the Class 0 protostellar system IRAS 16293-2422 taken with the Very Large Array (VLA) at multiple wavelengths between 7 mm and 15 cm (41 GHz down to 2 GHz), as well as single-epoch Atacama Large Millimeter/submillimeter Array (ALMA) continuum observations covering the range from 0.4 to 1.3 mm (700 GHz down to 230 GHz). The new VLA observations confirm that source A2 is a protostar driving episodic mass ejections, and reveal the complex relative motion between A2 and A1. The spectrum of component B can be described by a single power law ($S_{\nu }\propto {\nu }^{2.28}$) over the entire range from 3 to 700 GHz (10 cm down to 0.4 mm), suggesting that the emission is entirely dominated by dust even at $\lambda$ = 10 cm. Finally, the size of source B appears to increase with frequency up to 41 GHz, remaining roughly constant (at $0^{\prime \prime }.39$ $\equiv$ 55 AU) at higher frequencies. We interpret this as evidence that source B is a dusty structure of finite size that becomes increasingly optically thick at higher frequencies until, in the millimeter regime, the source becomes entirely optically thick. The lack of excess free-free emission at long wavelengths, combined with the absence of high-velocity molecular emission indicates that source B does not drive a powerful outflow, and might indicate that source B is at a particularly early stage of its evolution.

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Cited by in corpus (13)

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• The young protostellar disk in IRAS16293-2422 B is hot and shows signatures of gravitational instability
• Substructures in the Disk-Forming Region of the Class 0 Low-Mass Protostellar Source IRAS 16293-2422 Source A on a 10 au Scale
• The ALMA-PILS survey: propyne (CH${}_3$CCH) in IRAS 16293$-$2422
• Dust hot spots at 10 au scales around the Class 0 binary IRAS 16293-2422 A: a departure from the passive irradiation model
• Detection of Irregular, Sub-mm Opaque Structures in the Orion Molecular Clouds: Protostars within 10000 years of formation?
• ORion Alma New GEneration Survey (ORANGES) I. Dust continuum and free-free emission of OMC-2/3 filament protostars
• Discovery of a 500 au Protobinary in the Massive Prestellar Core G11.92-0.61 MM2
• The molecular environment of the solar-type protostar IRAS 16293-2422
• A 16 au Binary in the Class 0 Protostar L1157 MMS
• Rotating Motion of the Outflow of IRAS 16293-2422 A1 at its Origin Point near the Protostar