The Duplicity of IRAS 16293-2422: A Protobinary Star?
Abstract
Continuum maps at wavelengths of 6 cm and 2 cm of the region surrounding the infrared object IRAS 16293-2422 reveal two related sources, A and B separated by ∼5" (750 AU) along P.A. -50°. These sources lie within the 3 mm continuum source mapped by Mundy, Wilking, and Myers, which located density maxima of the dust disk at the core of the surrounding L1689N molecular cloud. Both the A and B sites of centimeter wave emission probably arise from ionized gas associated with distinct sites of star formation within this dense core. Thus IRAS 16293-2422 presents a rare opportunity to observe a binary system in its earliest stages of formation.
Higher resolution maps reveal that the brighter source, IRAS 16293- 2422A, is comprised of two unresolved sources, Al and A2, separated by 47 AU in projected distance, approximately perpendicular to the line between the more widely separated objects. A modest velocity-segregated cluster of water masers identifies these sources as associated with a bipolar flow, which must be collimated on a scale smaller than 50 AU. The ionized gas apparently exists as a trace constituent in a region where magnetohydrodynamic shocks impinging on the ambient cloud excite maser emission. Several arguments suggest that object B is less evolved than object A, and may be in a prestellar phase of its evolution. Interaction of the cores containing these objects may explain the complex pattern of the bipolar flow mapped by Wootten and Loren.- Publication:
-
The Astrophysical Journal
- Pub Date:
- February 1989
- DOI:
- 10.1086/167156
- Bibcode:
- 1989ApJ...337..858W
- Keywords:
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- INFRARED: SOURCES;
- STARS: BINARIES;
- STARS: FORMATION;
- STARS: INDIVIDUAL ALPHANUMERIC: IRAS 16293-2422;
- STARS: RADIO RADIATION