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C ARMA L arge A rea S tar-formation S urve Y

C ARMA L arge A rea S tar-formation S urve Y. Completing observations of 5 regions of 120-200 square arcminutes with 7” angular resolution in the J=1-0 transitions of HCO+, HCN, and N2H+

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C ARMA L arge A rea S tar-formation S urve Y

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  1. CARMALargeAreaStar-formationSurveY • Completing observations of 5 regions of 120-200 square arcminutes with 7” angular resolution in the J=1-0 transitions of HCO+, HCN, and N2H+ • Regions are in the Perseus and Serpens molecular clouds – covered by the c2d Spitzer Legacy project which characterized the young stellar population • Using CARMA to get interferometric and single-dish data to make maps of the full emission • Completed last week: 600 hours total array time

  2. Approximate CARMA mapping areas ~3.5 pc NGC 1333 High-Activity ~100 sq. arcmin. ~5.5 pc Barnard 1 Moderate-Activity ~150 sq. arcmin. (focus of this paper) L1451 Low-Activity ~150 sq. arcmin Composite Herschel 250, 350, 500 μm view

  3. NGC 1333 SVS -13 Region N2H+ Emission Velocity Field HCO+ Emission HCN Emission

  4. NGC 1333 SVS-13 Herschel 350 microns versus N2H+ N2H+ emission tracks the structure in the long wavelength continuum…. The bright region to the northeast is a heated area associated with a reflection nebula. N2H+ traces gas >105 per cc and give velocity information.

  5. Beam size in above three maps Provides resolution to study individual objects in the context of the large scale cloud.

  6. Perseus B1 Region

  7. Herschel 250 μm N2H+ main core central filaments southern clumps HCN HCO+

  8. Object IdentificationMethods Cloudprops(best for sparse fields) Dendrograms (best for dense/blended fields) vs. Molecular Cloud structure is mostly hierarchical … dendrograms avoid small-scale segmentation and naturally capture large-scales in addition to the small-scales

  9. Capturing Large and Small Scales with Dendrogram Approach Moment Zero Maps of Leaves and Branches IRAS 2 region of NGC 1333 12 33 51 12 55 How do larger-scale gas structures compare to smaller-scale structures? 11 59 33 42 55 42 51 Leaf Branch 11 59 Facilitates an investigation of the turbulent properties of dense gas at different scales in a way that clumpfind-like segmentation would not allow

  10. Results: Non-Binary Dendrogram of NGC 1333 N2H+ (1-0) Integrated Intensity Maps We evaluated the size and kinematics of each identified gas structure 12 33 51 How do larger-scale gas structures compare to smaller-scale structures? 42 55 11 59 0.04 pc • Turbulence … across different spatial scales within a single cloud • … across different clouds at different stages of evolution?

  11. Results: Non-Binary Dendrogram of NGC 1333 N2H+ (1-0) Fitted Line Dispersion Maps We evaluated the size and kinematics of each identified gas structure 12 33 51 How do larger-scale gas structures compare to smaller-scale structures? 42 55 11 59 • Turbulence … across different spatial scales within a single cloud • … across different clouds at different stages of evolution?

  12. Results: Line Dispersion vs. Size in NGC 1333 Gas Structures - - - - H2 thermal dispersion N2H+ thermal dispersion … at 11 K and 25 K Capturing mean internal turbulence

  13. Results: Non-Binary Dendrogram Structure of Barnard 1 N2H+ (1-0) black = nearby protostellar outflows red = further from outflow activity Spitzer IRAC + N2H+ outline

  14. Results: Cross-Cloud Comparison Barnard 1 NGC 1333 vs. - - - - H2 thermal dispersion N2H+ thermal dispersion … at 9 K and 12 K - - - - H2 thermal dispersion N2H+ thermal dispersion … at 11 K and 25 K

  15. Results: Cross-Cloud Comparison Barnard 1 NGC 1333 vs. - - - - H2 thermal dispersion N2H+ thermal dispersion … at 9 K and 12 K - - - - H2 thermal dispersion N2H+ thermal dispersion … at 11 K and 25 K N2H+ moment 0 HCO+outflows • Observe supersonic turbulence at ~0.01 – 0.5 pc scales near active young stars • Indication that outflows are an important turbulent driver of the dense gas at these scales not an outflow

  16. Results: Cross-Cloud Comparison Barnard 1 NGC 1333 vs. - - - - H2 thermal dispersion N2H+ thermal dispersion … at 9 K and 12 K - - - - H2 thermal dispersion N2H+ thermal dispersion … at 11 K and 25 K • Observe subsonic turbulence in filamentary regions yet to form young, active stars • … expected if these dense gas filaments formed from supersonic turbulence • Next step to probe even larger scales and make connection to lower density gas not an outflow

  17. Summary • Wealth of kinematics on ~1000s of AU size scale– fully sampled spatial scales • Dendrograms used to decompose dense gas emission and explore kinematics of structures in CLASSy clouds • Compared turbulent linewidths of NGC 1333 and B1 gas structures: • Star formation feedback correlates with supersonic turbulence at the ~0.01 – 0.5 pc scale • B1 filament is a great region to probe turbulence driven star formation theories

  18. Smaller Scale Magnetic Field Simultaneously observed CO outflow Hull et al. 2013

  19. Smaller Scale Magnetic Field Inferred magnetic fields are more consistent with random or anti-aligned with the outflow axis. Maybe good news for young disks (Vorobyov2010, Joos et al. 2012, Li et al. 2013) Hull et al. 2013

  20. Disks? What about magnetic braking? TADPOL results for L1527 and VLA 1623– coupled with no disk detection of L1157— interesting trend Hull et al. 2013

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