Presentation is loading. Please wait.

Presentation is loading. Please wait.

CARMA Large Area Star-formation SurveY  Completing observations of 5 regions of 120-200 square arcminutes with 7” angular resolution in the J=1-0 transitions.

Similar presentations


Presentation on theme: "CARMA Large Area Star-formation SurveY  Completing observations of 5 regions of 120-200 square arcminutes with 7” angular resolution in the J=1-0 transitions."— Presentation transcript:

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

3 N 2 H+ Emission Velocity Field HCN Emission NGC 1333 SVS -13 Region HCO+ Emission

4 NGC 1333 SVS-13 Herschel 350 microns versus N 2 H + 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. N 2 H + traces gas >10 5 per cc and give velocity information.

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

6 Perseus B1 Region

7 main core central filaments southern clumps N2H+N2H+ HCNHCO + Herschel 250 μm

8

9

10

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

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

13 Integrated Intensity Maps 0.04 pc Results: Non-Binary Dendrogram of NGC 1333 N 2 H + (1-0) How do larger- scale gas structures compare to smaller-scale structures? We evaluated the size and kinematics of each identified gas structure Turbulence … across different spatial scales within a single cloud … across different clouds at different stages of evolution?

14 Fitted Line Dispersion Maps How do larger- scale gas structures compare to smaller-scale structures? Results: Non-Binary Dendrogram of NGC 1333 N 2 H + (1-0) We evaluated the size and kinematics of each identified gas structure Turbulence … across different spatial scales within a single cloud … across different clouds at different stages of evolution?

15 Results: Line Dispersion vs. Size in NGC 1333 Gas Structures Capturing mean internal turbulence - - - - H 2 thermal dispersion N 2 H + thermal dispersion … at 11 K and 25 K

16 Results: Non-Binary Dendrogram Structure of Barnard 1 N 2 H + (1-0) Spitzer IRAC + N 2 H + outline black = nearby protostellar outflows red = further from outflow activity

17 Results: Cross-Cloud Comparison Barnard 1 - - - - H 2 thermal dispersion N 2 H + thermal dispersion … at 9 K and 12 K vs. NGC 1333 - - - - H 2 thermal dispersion N 2 H + thermal dispersion … at 11 K and 25 K

18 Results: Cross-Cloud Comparison Barnard 1 - - - - H 2 thermal dispersion N 2 H + thermal dispersion … at 9 K and 12 K vs. NGC 1333 - - - - H 2 thermal dispersion N 2 H + thermal dispersion … at 11 K and 25 K  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 N 2 H + moment 0 HCO + outflows

19 Results: Cross-Cloud Comparison Barnard 1 - - - - H 2 thermal dispersion N 2 H + thermal dispersion … at 9 K and 12 K vs. NGC 1333 - - - - H 2 thermal dispersion N 2 H + 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

20 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 Summary

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

22 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 (Vorobyov 2010, Joos et al. 2012, Li et al. 2013) Hull et al. 2013

23 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


Download ppt "CARMA Large Area Star-formation SurveY  Completing observations of 5 regions of 120-200 square arcminutes with 7” angular resolution in the J=1-0 transitions."

Similar presentations


Ads by Google