SMA and JCMT Observations of IRAS in HCN J=4-3: From Circumbinary Envelope to Circumstellar Disk SMA JCMT 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, David J. Wilner 1, Phil C. Myers 1, & Ewine F. Van Dishoeck 3 1: C.f.A., 2: ASIAA, 3: Leiden

Introduction  Comprehensive view from outer extended envelopes (JCMT) to inner disk regions (SMA) uniformly. Combining SMA + JCMT How protostellar envelopes turn into inner ( < 500 AU) disks around the central protostars ? Low-mass protostars and disks form in protostellar envelopes (2000-AU AU) with infalling and rotating motion (Ohashi et al. 1996, 1997a,b). Binary Class 0 Protostars in Oph ---> Infalling and Rotating Envelope (Narayanan et al. 1998) Target: IRAS  Submm lines such as HCN 4-3 can trace higher-temp. (> 43 K) and density (> 10 8 cm -3 ) innermost of envelopes..

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

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 ” )

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

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

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

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

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

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 HC 15 N abundance factor 10 lower than A e.g. Nakamura & Li > fragmentation of the first bar after the contraction of the env. ---> difficult to make different age of fragments ---> Subsequent merging of fragments ?? 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 ‘’……

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 Combining Submm Single-Dish + Interferometer is important in low-mass protostellar env., since submm emission (> 60 K) more extended (> 1500 AU) than we thought. 2. Different Evolution of the Protobinary in the common Circumbinary Envelope

Discussion 3: Importance of Combining Single-dish and Interferometric Data cf. SMA obs. of CS (7-6) in L1551 IRS5 ~ only 11 % HCN: Trot ~ 43 K; CS: Trot ~ 66 K Interaction with outflows could maintain high T k extended ? Stellar Radiation only could not explain the extent (Lay et al. 1994) 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 !! HCN (4-3) Extent > 3000 AU ---> cannot be traced with the SMA (only ~25 % total flux recovered)

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 Compact (~ 500 AU) High-Vel. Disklike Structure with SW-NE Vel. Gradient toward Source A No HCN Counterpart associated with B SW-NE Vel. Gradient in the Low-Velocity Env. too Systemactic Increase of Line Width torward Source A High-Vel. Comp. More Significant at High-Resolutions SMA + JCMT HCN (4-3)

15 Jy beam -1 LSR Velocity (km s -1 ) HCN “core” inside C 18 O condensation Toward A (no condensation on B) HCN (4-3) Infalling profile Different from C 18 O (2-1) IRAS mm and Submm Molecular Emission

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

Comparison of Flux Between SMA and JCMT Excellent match !!

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

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

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

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

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

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 NE-SW Extended Low-Vel. NE-SW --> Swept-up Dense Gas by the outflow

Disussion 1: Origin of the Different Velocity Components