1 / 23

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 ,

samuelshepard
Download Presentation

SMA

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  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

More Related