Confirmation of a recent bipolar ejection in the very young hierarchical multiple system IRAS 16293-2422

Abstract

We present and analyze two new high-resolution (approx 0.3 arcsec), high-sensitivity (approx 50 uJy beam-1) Very Large Array 3.6 cm observations of IRAS 16293-2422 obtained in 2007 August and 2008 December. The components A2alpha and A2beta recently detected in this system are still present, and have moved roughly symmetrically away from source A2 at a projected velocity of 30-80 km s-1. This confirms that A2alpha and A2beta were formed as a consequence of a very recent bipolar ejection from A2. Powerful bipolar ejections have long been known to occur in low-mass young stars, but this is -to our knowledge-- the first time that such a dramatic one is observed from its very beginning. Under the reasonable assumption that the flux detected at radio wavelengths is optically thin free-free emission, one can estimate the mass of each ejecta to be of the order of 10^-8 Msun. If the ejecta were created as a consequence of an episode of enhanced mass loss accompanied by an increase in accretion onto the protostar, then the total luminosity of IRAS 16293-2422 ought to have increased by 10-60% over the course of at least several months. Between A2alpha and A2beta, component A2 has reappeared, and the relative position angle between A2 and A1 is found to have increased significantly since 2003-2005. This strongly suggests that A1 is a protostar rather than a shock feature, and that the A1/A2 pair is a tight binary system. Including component B, IRAS 16293-2422 therefore appears to be a very young hierarchical multiple system.

Accepted for publication in The Astrophysical Journal

References in corpus (5)

• Current Star Formation in the Ophiuchus and Perseus Molecular Clouds: Constraints and Comparisons from Unbiased Submillimeter and Mid-Infrared Surveys. II
• The CO Molecular Outflows of IRAS 16293-2422 Probed by the Submillimeter Array
• New Radio Sources and the Composite Structure of Component B in the Very Young Protostellar System IRAS 16293-2422
• Physical Structure and Dust Reprocessing in a sample of HH Jets
• The rotating molecular core and precessing outflow of the young stellar object Barnard 1c

Cited by in corpus (39)

• The ALMA Protostellar Interferometric Line Survey (PILS): First results from an unbiased submillimeter wavelength line survey of the Class 0 protostellar binary IRAS 16293-2422 with ALMA
• The VLA Nascent Disk and Multiplicity Survey of Perseus Protostars (VANDAM). II. Multiplicity of Protostars in the Perseus Molecular Cloud
• A Magnetized Jet from a Massive Protostar
• SMA Observations of Class 0 Protostars: A High-Angular Resolution Survey of Protostellar Binary Systems
• TIMASSS: The IRAS16293-2422 Millimeter And Submillimeter Spectral Survey. I. Observations, calibration and analysis of the line kinematics
• Radio Jets from Young Stellar Objects
• The Protostellar Luminosity Function
• The ALMA-PILS survey: Complex nitriles towards IRAS 16293--2422
• Chemical modelling of complex organic molecules with peptide-like bonds in star-forming regions
• Arcsecond resolution images of the chemical structure of the low-mass protostar IRAS 16293-2422
• Detection of a Magnetized Disk around a Very Young Protostar
• The Gould's Belt Very Large Array Survey I: The Ophiuchus complex
• The Bridge: a transient phenomenon of forming stellar multiples
• A revised distance to IRAS 16293$-$2422 from VLBA astrometry of associated water masers
• Orbital and mass constraints of the young binary system IRAS 16293-2422 A
• VLA and CARMA Observations of Protostars in the Cepheus Clouds: Sub-arcsecond Proto-Binaries Formed via Disk Fragmentation
• The ALMA-PILS survey: 3D modeling of the envelope, disks and dust filament of IRAS 16293-2422
• Dust Polarization Toward Embedded Protostars in Ophiuchus with ALMA. II. IRAS 16293-2422
• The ALMA-PILS survey: The first detection of doubly-deuterated methyl formate (CHD2OCHO) in the ISM
• Time Monitoring of Radio Jets and Magnetospheres in the Nearby Young Stellar Cluster R Coronae Australis
• ALMA CO J=6-5 observations of IRAS16293-2422: Shocks and entrainment
• A search for pre-substellar cores and proto-brown dwarf candidates in Taurus: multiwavelength analysis in the B213-L1495 clouds
• ALMA and VLA observations of the outflows in IRAS 16293-2422
• The ALMA-PILS survey: Gas dynamics in IRAS 16293$-$2422 and the connection between its two protostars
• On the origin of the molecular outflows in IRAS 16293-2422
• Temperature profiles of young disk-like structures: The case of IRAS 16293A
• Substructures in the Disk-Forming Region of the Class 0 Low-Mass Protostellar Source IRAS 16293-2422 Source A on a 10 au Scale
• The ALMA-PILS survey: propyne (CH${}_3$CCH) in IRAS 16293$-$2422
• Dust hot spots at 10 au scales around the Class 0 binary IRAS 16293-2422 A: a departure from the passive irradiation model
• On the nature of the compact sources in IRAS 16293-2422 seen in at centimeter to sub-millimeter wavelengths
• From large-scale to protostellar disk fragmentation into close binary stars
• A very young, compact bipolar H${}_2$O maser outflow in the intermediate-mass star-forming LkH$\alpha$ 234 region
• The compact, time-variable radio source projected inside W3(OH): Evidence for a Photoevaporated Disk?
• SMA observations towards the compact, short-lived bipolar water maser outflow in the LkHα 234 region
• 3D modelling of HCO${}^{+}$ and its isotopologues in the low-mass proto-star IRAS16293$-$2422
• Surveys of Clumps, Cores, and Condensations in the Cygnus X: II. Radio Properties of the Massive Dense Cores
• Radio monitoring of the periodically variable IR source LRLL 54361: No direct correlation between the radio and IR emissions
• Variability of the SiO thermal line emission toward the young L1448-mm outflow
• Rotating Motion of the Outflow of IRAS 16293-2422 A1 at its Origin Point near the Protostar