Arcsecond-Resolution Submillimeter HCN Imaging of the Binary Protostar IRAS 16293-2422

Abstract

(Abridged) With the SMA we have made high angular-resolution (~1" = 160 AU) observations of the protobinary system IRAS 16293-2422 in the J = 4-3 lines of HCN and HC^15N, and in the continuum at 354.5 GHz. The HCN (4-3) line was also observed using the JCMT to supply missing short spacing information. Submillimeter continuum emission is detected from the individual binary components with a separation of ~5". The HC^15N (4-3) emission has revealed a compact (~500 AU) flattened structure (P.A. = -16 degree) associated with Source A, and shows a velocity gradient along the projected minor axis, which can be interpreted as an infalling gas motion. Our HCN image including the short-spacing information shows an extended (~3000 AU) circumbinary envelope as well as the compact structure associated with Source A. A toy model consisting of a flattened structure with radial infall towards a 1 Msun central star reproduces the HCN/HC^15N position-velocity diagram along the minor axis of the HC^15N emission. In the extended envelope there is also a North-East (Blue) to South-West (Red) velocity gradient across the binary alignment, which is likely to reflect gas motion in the swept-up dense gas associated with the molecular outflow from Source A. At Source B, there is only a weak compact structure with much narrower line widths (~2 km/s) seen in the optically-thin HC^15N emission than that at Source A (>10 km/s), and there is no clearly defined bipolar molecular outflow associated with Source B. These results imply the different evolutionary stages between Source A and B in the common circumbinary envelope.

31 pages (incl. 9 figures), accepted by ApJ

References in corpus (21)

• The Submillimeter Array
• Does IRAS 16293-2422 have a hot core? Chemical inventory and abundance changes in its protostellar environment
• Near-arcsecond resolution observations of the hot corino of the solar type protostar IRAS 16293-2422
• Infall, Outflow, Rotation, and Turbulent Motions of Dense Gas within NGC 1333 IRAS 4
• IRAS 16293-2422: proper motions, jet precession, the hot core, and the unambiguous detection of infall
• Organic Molecules in Low-Mass Protostellar Hot Cores: Submillimeter Imaging of IRAS 16293-2422
• Probing the Early Stages of Low-Mass Star Formation in LDN 1689N: Dust and Water in IRAS 16293-2422A, B, and E
• Discovery of a Low Mass Bipolar Molecular Outflow from L1014-IRS with the Submillimeter Array
• From infall to rotation around young stellar objects: A transitional phase with a 2000 AU radius contracting disk?
• On the origin of H2CO abundance enhancements in low-mass protostars
• B335: A Laboratory for Astrochemistry in a Collapsing Cloud
• IRAS 16293-2442B: A Compact, Possibly Isolated Protoplanetary Disk in a Class 0 Object
• IRAS 11590-6452 in BHR 71 - a binary protostellar system?
• Protostellar holes: Spitzer Space Telescope observations of the protostellar binary IRAS16293-2422
• A Single Circumstellar Disk in the SVS 13 Close Binary System
• Millimeter- and Submillimeter-Wave Observations of the OMC-2/3 Region; I. Dispersing and Rotating Core around an Intermediate-mass Protostar MMS 7
• Submillimeter Array Observations of L1551 IRS 5 in CS (J=7-6)
• Binary and Multiple Star Formation in Magnetic Clouds: Bar Growth and Fragmentation
• Organic Molecules in the Hot Corinos and Circumstellar Disks of IRAS 16293-2422
• Interaction between the Outflow and the Core in IRAM 04191+1522
• The Dense Molecular Cores in the IRAS 21391+5802 region

Cited by in corpus (42)

• ON the Nature of the Local Spiral Arm of the Milky Way
• TIMASSS: The IRAS16293-2422 Millimeter And Submillimeter Spectral Survey. I. Observations, calibration and analysis of the line kinematics
• Infalling-Rotating Motion and Associated Chemical Change in the Envelope of IRAS 16293-2422 Source A Studied with ALMA
• An interferometric study of the low-mass protostar IRAS 16293-2422: small scale organic chemistry
• Ingredients for Solar-like Systems: protostar IRAS 16293-2422 B versus comet 67P/Churyumov-Gerasimenko
• The first ALMA view of IRAS 16293-2422: Direct detection of infall onto source B and high-resolution kinematics of source A
• IRAS 16293: A "Magnetic" Tale of Two Cores
• ALMA Observations of Infalling Flows toward the Keplerian Disk around the Class I Protostar L1489 IRS
• Arcsecond resolution images of the chemical structure of the low-mass protostar IRAS 16293-2422
• Gas infall towards Sgr A* from the clumpy circumnuclear disk
• A Keplerian Circumbinary Disk around the Protobinary System L1551 NE
• Detection of a Magnetized Disk around a Very Young Protostar
• Observations of Infalling and Rotational Motions on a 1,000-AU Scale around 17 Class 0 and 0/I Protostars: Hints of Disk Growth and Magnetic Braking?
• Millimeter- and Submillimeter-Wave Observations of the OMC-2/3 Region. II. Observational Evidence for Outflow-Triggered Star Formation in the OMC-2 FIR 3/4 Region
• Spiral Arms, Infall, and Misalignment of the Circumbinary Disk from the Circumstellar Disks in the Protostellar Binary System L1551 NE
• Transition from the Infalling Envelope to the Keplerian Disk around L1551 IRS 5
• HiRes Deconvolved Spitzer Images of 89 Protostellar Jets and Outflows: New Data on Evolution of Outflow Morphology
• High-Velocity Jets and Slowly Rotating Envelope in B335
• Observations of nitrogen isotope fractionation in deeply embedded protostars
• The CO Molecular Outflows of IRAS 16293-2422 Probed by the Submillimeter Array
• ALMA CO J=6-5 observations of IRAS16293-2422: Shocks and entrainment
• Unveiling the detailed density and velocity structures of the protostellar core B335
• ALMA follows streaming of dense gas down to 40 pc from the supermassive black hole in NGC1097
• The ALMA-PILS survey: Gas dynamics in IRAS 16293$-$2422 and the connection between its two protostars
• Evaporation of grain-surface species by shock waves in proto-planetary disk
• Millimeter- and Submillimeter-Wave Observations of the OMC-2/3 region. IV Interaction between the Outflow and the Dense Gas in the Cluster Forming Region of OMC-2 FIR 6
• The young protostellar disk in IRAS16293-2422 B is hot and shows signatures of gravitational instability
• Successive deuteration in low-mass star-forming regions: the case of D${}_2$-methanol (CHD${}_2$OH) in IRAS 16293-2422
• CH in absorption in IRAS16293-2422
• Substructures in the Disk-Forming Region of the Class 0 Low-Mass Protostellar Source IRAS 16293-2422 Source A on a 10 au Scale
• Substellar-Mass Condensations in Prestellar Cores
• Initial conditions for star formation in clusters: physical and kinematical structure of the starless core Oph A-N6
• The circumestellar disk of the B0 protostar powering the HH 80-81 radio jet
• Evidence for Infalling Gas of Low Angular Momentum towards the L1551 NE Keplerian Circumbinary Disk
• Dynamical structure of the inner 100 AU of the deeply embedded protostar IRAS 16293-2422
• ASTE observations in the 345 GHz window towards the HII region N113 of the Large Magellanic Cloud
• Exploring the Origins of Earth's Nitrogen: Astronomical Observations of Nitrogen-bearing Organics in Protostellar Environments
• The formation of glycolonitrile (HOCH${}_2$CN) from reactions of C${}^{+}$ with HCN and HNC on icy grain mantles
• Skewed Distributions and Opposite Velocity Gradients of Submillimeter Molecular Lines in Low-Mass Protostellar Envelopes
• The Distinct Evolutionary Nature of two Class 0 Protostars in Serpens Main SMM4
• HII region G46.5-0.2: the interplay between ionizing radiation, molecular gas and star formation
• CAB: Towards the RNA-world in the interstellar medium -- detection of urea, and search of 2-amino-oxazole and simple sugars