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SMA

SMA and JCMT Observations of IRAS 16293-2422 in HCN J=4-3: From Circumbinary Envelope to Circumstellar Disk. JCMT. SMA. Shigehisa Takakuwa 1 , Nagayoshi Ohashi 2 , Tyler L. Bourke 1 , Paul T. P. Ho 1 , Jes K. Jorgensen 1 , Yi-Jehng Kuan 2 , Naomi Hirano 2 ,

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SMA

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  1. SMA and JCMT Observations ofIRAS 16293-2422 in HCN J=4-3:From Circumbinary Envelope to Circumstellar Disk JCMT SMA Shigehisa Takakuwa1, Nagayoshi Ohashi2, Tyler L. Bourke1, Paul T. P. Ho1, Jes K. Jorgensen1, Yi-Jehng Kuan2, Naomi Hirano2, David J. Wilner1, Phil C. Myers1, & Ewine F. Van Dishoeck3 1: C.f.A., 2: ASIAA, 3: Leiden

  2. Introduction Low-mass protostars and disks form in protostellar envelopes (2000-AU - 10000 AU) with infalling and rotating motion (Ohashi et al. 1996, 1997a,b). How protostellar envelopes turn into inner ( < 500 AU) disks around the central protostars ? Combining SMA + JCMT • Submm lines such as HCN 4-3 can trace higher-temp. (> 43 K) and density (> 108 cm-3) innermost of envelopes. • . • Comprehensive view from outer extended envelopes (JCMT) to inner disk regions (SMA) uniformly. Target: IRAS 16293-2422 Binary Class 0 Protostars in Oph ---> Infalling and Rotating Envelope (Narayanan et al. 1998)

  3. IRAS 16293-2422 SMA 354 GHz Continuum B Source A 160 AU Beam 1.1×0.6 arcsec B:4.0 Jy ~ 0.080 Mo 0.9×0.9 arcsec A:3.8 Jy ~ 0.076 Mo 1.9×0.9 arcsec NE-SW elongation (P.A. 32.6 degree)

  4. Comparison of Total Integrated Intensity Maps in HCN (4-3) JCMT HCN: ~ 3000 AU “Envelope” on A SMA HCN: Compact (~ 500 AU) Disklike Structure on A + some filament SMA + JCMT: Compact Structure Embedded in the Extended Envelope. Wide Spatial Range (from 40 to 1”)

  5. HCN (4-3) Velocity Structure + NE-SW Gradient perpendicularly (see Poster 82 by Yeh et al.) NW-SE Gradient in the Circumbi. Env around the bin. axis NE-SW Gradient in the compact disk at A ~ Parallel to outflow ---> Infall Note: HCN avoids B.. Extended Envelope with 2 Vel. Grad. + High-Velocity Compact Disk at A with Vel. Grad.

  6. HCN (4-3) Velocity Structure 2 Mean Vel. Map Line Width Map Line Width systematically increase toward Source A Outer Envelope --> NW-SE Gradient Around the Binary --> NE-SW Gradient Perpendicular !! ---> Compact High-vel. Disklike Structure

  7. Comparison of HCN (4-3) Line Profiles SMA+JCMT --> extended lower-velocity components than SMA SMA --> the compact higher-velocity component at Source A than JCMT SMA + JCMT --> Infalling asymmetry with (possible) negative dip

  8. Discussion 1: Origin of the Different Velocity Components Extended, Low-Velocity Envelope dv dv Compact, High-Velocity Disklike Structure P-V Diagram along the NE-SW gradient through Source A Compact High-Vel. Strucrture --> Infalling Disk on 1M (~ 6 x 10-4 M/yr) Extended Low-Vel.NE-SW --> Swept-up Dense Gas by the outflow

  9. Origin of the Different Velocity Components Compact (~ 500 AU) High-Vel. Component at Source A ---> Infalling Disk on 1M Extended Low-Vel.NE-SW --> Swept-up Dense Gas by the outflow Outer NW-SE gradient ---> Rotating Circumbinary Envelope as already reported

  10. Discussion 2: Different Evolution of the Binary Protostars ? Source A ---> compact (~ 500 AU) disklike structure in HCN Source B ---> No clear HCN disklike structure No outflow associated HC15N abundance factor 10 lower than A A and B in the different evolutionary stages in the common envelope Theoretically it is difficult to make binary companions at different evolution in the ``common envelope‘’…… e.g. Nakamura & Li 2003 ---> fragmentation of the first bar after the contraction of the env. ---> difficult to make different age of fragments ---> Subsequent merging of fragments ??

  11. Summary 1. Combined SMA+JCMT image of I16293 in the HCN emission revealed detailed velocity structure in the cirumbinary Env. Rotating Circumbinary Env. + Infalling Disk at Source A + Outflowing Gas 2. Different Evolution of the Protobinary in the common Circumbinary Envelope Combining Submm Single-Dish + Interferometer is important in low-mass protostellar env., since submm emission (> 60 K) more extended (> 1500 AU) than we thought.

  12. Discussion 3:Importance of Combining Single-dish and Interferometric Data HCN (4-3) Extent > 3000 AU ---> cannot be traced with the SMA (only ~25 % total flux recovered) cf. SMA obs. of CS (7-6) in L1551 IRS5 ~ only 11 % HCN: Trot ~ 43 K; CS: Trot ~ 66 K Stellar Radiation only could not explain the extent (Lay et al. 1994) Interaction with outflows could maintain high Tk extended ? Submm lines are likely to be more extended in the low-mass Env. than we thought It is quite important to combine Single-dish and Interfer. Data; We can study comprehensive Vel. structure at wide spatial range; that is, from Envelope (~ 3000 AU) to Disk (~ 100 AU) ACA in ALMA is critical !!

  13. Summary of the Results Two Intense 354 GHz Continuum Sources Detected with the SMA; Source A: NE-SW Elongation, 3.8 Jy, 1.9 x 0.9 arcsec Source B: Circular, More Compact 4.0 Jy, 0.9 x 0.9 arcsec JCMT HCN (4-3)---> 3000 AU-scale Circumbinary Envelope SE-NW Vel. Gradient along the Binary Axis as Reported SMA + JCMT HCN (4-3) SW-NEVel. Gradient in the Low-Velocity Env. too Compact (~ 500 AU) High-Vel. Disklike Structure with SW-NEVel. Gradient toward Source A No HCN Counterpart associated with B Systemactic Increase of Line Width torward Source A High-Vel. Comp. More Significant at High-Resolutions

  14. IRAS 16293-2422 mm and Submm Molecular Emission 20 Jy beam-1 10 0 15 5 0 10 -5 -10 LSR Velocity (km s-1) HCN “core” inside C18O condensation Toward A (no condensation on B) HCN (4-3) Infalling profile Different from C18O (2-1)

  15. Make JCMT Visibilities Original JCMT Map Deconvolved with the JCMT beam Primary Beam De-correction Make Visibilities By uvrandom and uvmodel

  16. Comparison of Flux Between SMA and JCMT Excellent match !!

  17. Synthesized Beam SMA Only SMA + JCMT Negative Lobe Significantly Suppressed & Better Sidelobes

  18. HCN (4-3) Velocity Structure 1 JCMT JCMT NW - SE gradient In the Env. along the binary axis as already reported SMA SMA+JCMT SMA Compact High-Vel. toward A, Emission gone around Vsys SMA+JCMT Compact + Extended Emission See next

  19. HCN Line Profiles At Higher Resolution ---> More High-Vel. Comp., Higher-Temp., Deeper Dip (possibly negative) Compare SMA+JCMT and SMA Spectra ---> SMA miss low-velocity (= extended) Components

  20. Discussion CO 2-1 Outflow (Sherry et al. 2005) NEE-SWW overall from Source A • Low-Vel. NE-SW • Swept-up dense gas by the outflow ? High-Vel. Compact Blue-Red HCN at A ~ parallel to outflow High-Vel. Diffuse --> Rim of outflow ---> Position-Velocity (P-V) diagram

  21. P-V Diagram along the binary, NW-SE gradient Compact, High-Velocity Disklike Structure Extended Ambient Gas No clear Vel. Gradient --> No Rotation Mixture of High-Vel. Compact, Ambient Gas, & Rotating Circumbinary Envelope

  22. Origin of the Different Velocity Components Compact (~ 500 AU) High-Vel. Component at Source A ---> Accretion Disk on 1M without clear rotation Outer NW-SE gradient ---> Rotating Circumbinary Envelope as already reported Extended Low-Vel.NE-SW --> Swept-up Dense Gas by the outflow

  23. Disussion 1: Origin of the Different Velocity Components

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