Large-Scale Projects with the SMA and CARMA: MASSES and CLASSy. Katherine I. Lee (Harvard-Smithsonian CfA)

Transcription

1 Large-Scale Projects with the SMA and CARMA: MASSES and CLASSy Katherine I. Lee (Harvard-Smithsonian CfA) HHSF 2015, May 19, 2015

2 MASSES: Mass Assembly of Stellar Systems and their Evolution with the SMA Michael Dunham (PI; CfA), Phil Myers (CfA), Lars Kristensen (CfA), Alyssa Goodman (CfA), Tylor Bourke (SKA), John Tobin (Leiden), Jaime Pineda (MPE), Jes Jorgensen (Copenhagen), Hector Arce (Yale), Stella Offner (UMass), Eduard Vorobyov (Vienna) CLASSy: CARMA Large Area Star Formation Survey Manuel Fernandez-Lopez (Illinois/IAR), Shaye Storm (Maryland), Leslie Looney (Illinois), Lee Mundy (Maryland), Dominique Segura-Cox (Illinois), Peter Teuben (Maryland), Erik Rosolowsky (Univ. of Alberta), Hector Arce (Yale), Eve Ostriker (Princeton), Yancy Shirley (Univ. of Arizona), and the CLASSy Team

3 MASSES Mass Assembly of Stellar Systems and their Evolu4on with the SMA How Do Stars Gain Their Mass? To what extent do ou1lows regulate accre7on? When, where, and how do cores and disks fragment into mul7ple systems? How does angular momentum evolve as mass accretes onto stars?

4 MASSES Mass Assembly of Stellar Systems and their Evolu4on with the SMA Largest interferometric sample of protostars in molecular lines from the same region with the same angular resolution Survey all Perseus protostars (73 objects) Full complement of dense gas and ou1low tracers: 12CO, C18O, N2D+, HCO+ Subcompact + extended configura7ons: 3.5 and 1 resolu7on, respec7vely Approximately 60 tracks (600 hours) over 2 3 years 40% SUB, <10% EXT

5 Gallery of Opening Angles Increasing Tbol (from younger to older sources) Tbol: The temperature of a blackbody having the same mean frequency as the observed continuum spectrum

6 Misaligned in Binaries Increasing Tbol (from younger to older sources) 1000 AU

7 Misaligned in Binaries Increasing Tbol (from younger to older sources)

8 Misaligned in Binaries 65% of the binary/mul4ple systems show misalignment Our results suggest that the binaries are not formed with aligned rota4onal axes at earliest stages Turbulent Fragmenta4on: Random alignment (e.g., Offner 2010, Bate 2012) Turbulent Fragmenta4on Model Offner et al. (2011) Disk fragmenta4on: Aligned axes (e.g., KraUer et al. 2010, Vorobyov et al. 2010)

9 Kinema4cs vs. Mul4plicity Probed by C 18 O(2-1) 1 st moment maps of C 18 O(2-1) Provide Insights to the Fragmentation Process Dunham et al. (in prep) VANDAM (PI: John Tobin): A con4nuum survey at 8mm with VLA toward protostars in Perseus. Reveals mul4plicity with a 15 AU resolu4on Compare kinema4cs revealed by MASSES (rota4on & turbulence) with level of fragmenta4on revealed by VANDAM

10 L1448N: A Mul4ple System SMA 1.3mm from MASSES NW: 0.17 M A: 0.1 M 1000 AU B: 0.9 M

11 L1448N: Hierarchical Fragmenta4on 1 Fragment 1000 AU NW 3 Fragments A B 2 Fragments Fragments revealed by VLA survey 15 AU resolu4on Ka band: 8mm (23 GHz) Fragments are suggested to be protostars

12 L1448- N: Core Kinema4cs with C 18 O 2 fragmt NW 1 fragmt A B 3 fragmts Lee, Dunham, Myers et al. (in prep)

13 Velocity Gradients and Dispersions 1 st moment map Source Frag V grad (km/s/ps) σ NT (km/s) B ± ± 0.05 NW 2 89 ± ± 0.07 A 1 67 ± ± D velocity gradient fitting Outflow axes nearly perpendicular to Vgrad axes, suggesting rotation V grad vs. level of fragmentation σ NT vs. level of fragmentation

14 CARMA Large Area Star Formation Survey (CLASSy)

15 N2H+, HCO+, HCN in Five Star-Forming Regions (Storm et al. 2014) 7 angular resolution (Storm et al. 2015, in prep)

16 N 2 H +, HCO +, HCN in Five Star-Forming Regions Serpens Main Serpens South Lee et al. (2014) Fernández- López et al. (2014)

17 Velocity Gradients Across Filaments

18 Velocity Gradients Across Filaments

19 Summary MASSES (with the SMA) MASSES surveys all the known protostars in Perseus ( 12 CO, C 18 O, N 2 D + etc.) 65% of binary systems show misaligned outflows L1448N shows a system of hierarchical fragmentation Fragmentation level shows a trend with velocity gradients No trend between non-thermal velocity dispersions and fragmentation level CLASSy (with CARMA) CLASSy mapped five star-forming regions in N 2 H +, HCN, and HCO + NGC1333, B1, L1451, Serpens Main, Serpens South Several filaments showed velocity gradients perpendicular to filaments, consistent with filamentary formation from converging flows