WIYN Image: T.A. Rector, B. Wolpa and G. Jacoby (NOAO/AURA/NSF) and Hubble Heritage Team (STScI/AURA/NASA) Stars Forming in a Dynamic Interstellar Medium Alyssa A. Goodman Harvard-Smithsonian Center for Astrophysics cfa-

Stars Forming in a Dynamic ISM When the World Stood Still (except at the last minute) Allowing Time to Tick, and not always start at zero –Episodic Outflows –PV Ceph: Protostar Caught Speeding? COMPLETE sampling as a path to the answer –Carefully-designed statistical questions –Serendipity (so far: warm dust ring around X-ray source in Ophichus, odd velocity features in Perseus…)

Standing Still, Until the Last Minute Global Instability (e.g. Jeans) Fragments Cloud (hierarchically) time~10 6 years Hoyle 1953 Fragments Collapse Under Gravity into “Protostars” time~10 5 years

Standing Still, Until the Last Minute A Group of Young “Zero-Age Main Sequence” Stars is Born

Molecular or Dark Clouds "Cores" and Outflows Ticking, from t=0 Jets and Disks Extrasolar System 1 pc

BUT… How long does each “phase” last and how are they mixed? (Big cloud--“Starless” Core--Outflow--Planet Formation--Clearing) What is the time-history of star production in a “cloud”? Are all the stars formed still “there”? How do processes in each phase impact upon each other? (Sequential star formation, outflows reshaping clouds…)

Stars Forming in a Dynamic ISM Bate, Bonnell & Bromm 2002 MHD turbulence gives “t=0” conditions; Jeans mass=1 M sun 50 M sun, 0.38 pc, n avg =3 x 10 5 ptcls/cc forms ~50 objects T=10 K SPH, no B or  movie=1.4 free-fall times

What is the right “starting” condition? Stone, Gammie & Ostriker 1999 Driven Turbulence; M  K; no gravity Colors: log density Computational volume: Dark blue lines: B-field Red : isosurface of passive contaminant after saturation  =0.01  =1  T /10 K  n H 2 /100 cm -3  B /1.4  G  2

Simulated map, based on work of Padoan, Nordlund, Juvela, et al. Excerpt from realization used in Padoan & Goodman Evaluating Simulated Spectral Line Map of MHD Simulations: The Spectral Correlation Function (SCF)

“Equipartition” Models How Well can Molecular Clouds be Modeled, Today? Summary Results from SCF Analysis Falloff of Correlation with Scale Magnitude of Spectral Correlation at 1 pc Padoan & Goodman 2002 “Reality” Scaled “Superalfvenic” Models “Stochastic” Models

Cores: Islands of Calm in a Turbulent Sea? "Rolling Waves" by KanO Tsunenobu © The Idemitsu Museum of Arts.

Goodman, Barranco, Wilner & Heyer 1998 Islands of Calm in a Turbulent Sea

Islands (a.k.a. Dense Cores) Berkeley Astrophysical Fluid Dynamics Group Barranco & Goodman 1998 AMR Simulation Simulated NH 3 Map Ask about velocity gradients later

Goodman, Barranco, Wilner & Heyer 1998 Observed ‘Starting’ Cores: 0.1 pc Islands of (Relative) Calm  v [km s ] T A [K] TMC-1C, OH 1667 MHz  v=(0.67±0.02)T A -0.6±  v intrinsic [km s ] T A [K] TMC-1C, NH 3 (1, 1)  v intrinsic =(0.25±0.02)T A -0.10±0.05 “Coherent Core”“Dark Cloud” Size Scale Velocity Dispersion

Order in a Sea of Chaos Order; N~R 0.9 ~0.1 pc (in Taurus) Chaos; N~R 0.1

So, can we simulate ticking time? MHD Simulations give good approximation of dynamic ISM, on >>0.1 pc scales Physical scale (reality) of ~0.1 pc SPH simulations starting from a turbulent “t=0” is debatable (no B, T=const, etc.) –Observations indicate relative calm just before stars form

Why care about time? Mass [M sun ] Velocity [km s -1 ] Power-law Slope of Sum = -2.7 (arbitrarily >2) Slope of Each Outburst = -2 as in Matzner & McKee 2000 Example 1: Episodicity changes outflow’s Energy/Momentum Deposition/time Example 2: (Some) Young stars may zoom through ISM

Example 1: Episodicity in Outflows See references in H. Arce’s Thesis 2001

L1448 Bachiller et al B5 Yu Billawala & Bally 1999 Lada & Fich 1996 Bachiller, Tafalla & Cernicharo 1994 Position-Velocity Diagrams show YSO Outflows are Highly Episodic Velocity Position

Outflow Episodes:Position-Velocity Diagrams Figure from Arce & Goodman 200az1a HH300 NGC2264

“Steep” Mass-Velocity Relations HH300 (Arce & Goodman 2001a) Slope steepens when  corrections made –Previously unaccounted-for mass at low velocities Slope often (much) steeper than “canonical” -2 Seems burstier sources have steeper slopes? Mass/Velocity Velocity

Mass-Velocity Relations in Episodic Outflows: Steep Slopes result from Summed Bursts Power-law Slope of Sum = -2.7 (arbitrarily >2) Slope of Each Outburst = -2 as in Matzner & McKee 2000 Arce & Goodman 2001b

Example 2: Powering source of (some) outflows may zoom through ISM

1 pc “Giant” Herbig- Haro Flow from PV Ceph Image from Reipurth, Bally & Devine 1997

moving ?? PV Ceph Episodic ejections from a precessing or wobbling moving ?? source Goodman & Arce 2002

HST WFPC2 Overlay: Padgett et al Arce & Goodman 2002 Optical “cones” Elongated ~N-S Dense gas elongated along direction of motion

Goodman & Arce 2002 Trail & Jet

How much gas will be pulled along for the ride? Goodman & Arce 2002

Just how fast is PV Ceph going?

Insights from a “Plasmon” Model Initial jet 250 km s - 1 ; star motion 10 km s -1 Goodman & Arce 2002

Insights from a “Plasmon” Model Goodman & Arce 2002

Stars Forming in a Dynamic ISM When the World Stood Still (except at the last minute) Allowing Time to Tick, and not always start at zero –Episodic Outflows –PV Ceph: Protostar Caught Speeding? COMPLETE sampling as a path to the answer –Carefully-designed statistical questions –Serendipity (so far: warm dust ring around X-ray source in Ophichus, odd velocity features in Perseus…)

Un(coordinated) Molecular- Probe Line, Extinction and Thermal Emission Observations Molecular Line Map Nagahama et al CO (1-0) Survey Lombardi & Alves 2001Johnstone et al. 2001

COMPLETE sampling as a path to the answer The COordinated Molecular Probe Line Extinction Thermal Emission Survey Alyssa A. Goodman, Principal Investigator (CfA) João Alves (ESA, Germany) Héctor Arce (Caltech) Paola Caselli (Arcetri, Italy) James DiFrancesco (HIA, Canada) Doug Johnstone (HIA, Canada) Scott Schnee (CfA, PhD student) Mario Tafalla (OAS, Spain) Tom Wilson (MPIfR/SMTO)

COMPLETE, Part 1 Observations: Mid- and Far-IR SIRTF Legacy Observations: dust temperature and column density maps ~5 degrees mapped with ~15" resolution (at 70  m) NICER/2MASS Extinction Mapping: dust column density maps ~5 degrees mapped with ~5' resolution SCUBA Observations: dust column density maps, finds all "cold" source ~20" resolution on all A V >2” FCRAO/SEQUOIA 13 CO and 13 CO Observations: gas temperature, density and velocity information ~40" resolution on all A V >1 Science: –Combined Thermal Emission data: dust spectral-energy distributions, giving emissivity, T dust and N dust –Extinction/Thermal Emission inter-comparison: unprecedented constraints on dust properties and cloud distances, in addition to high-dynamic range N dust map –Spectral-line/N dust Comparisons Systematic censes of inflow, outflow & turbulent motions enabled –CO maps in conjunction with SIRTF point sources will comprise YSO outflow census 5 degrees (~tens of pc) SIRTF Legacy Coverage of Perseus >10-degree scale Near- IR Extinction, Molecular Line and Dust Emission Surveys of Perseus, Ophiuchus & Serpens

COMPLE TE, Part 2 (2003-5) Observations, using target list generated from Part 1:  NICER/8-m/IR camera Observations: best density profiles for dust associated with "cores". ~10" resolution  FCRAO + IRAM N 2 H + Observations: gas temperature, density and velocity information for "cores” ~15" resolution Science:  Multiplicity/fragmentation studies  Detailed modeling of pressure structure on <0.3 pc scales  Searches for the "loss" of turbulent energy (coherence) FCRAO N 2 H + map with CS spectra superimposed. (Lee, Myers & Tafalla 2001). 10 pc to 0.01 pc

A statistical question for COMPLETE: How Many Outflows are There at Once? What is their cumulative effect? Action of Outflows(?) in NGC 1333 SCUBA 850 mm Image shows N dust (Sandell & Knee 2001) Dotted lines show CO outflow orientations (Knee & Sandell 2000)

Is this Really Possible Now? 1 day for a 13 CO map then 1 minute for a 13 CO map now

…yes, it’s possible

COMPLETE: JCMT/SCUBA >10 mag A V Perseus Ophiuchus 10 pc Johnstone, Goodman & the COMPLETE team, SCUBA 2003(?!) ~100 hours at SCUBA

COMPLETE Preview: Discovery of a Heated Dust Ring in Ophiuchus Goodman, Li & Schnee pc

…and the famous “1RXS J ” is right in the Middle !? 2 pc

WIYN Image: T.A. Rector, B. Wolpa and G. Jacoby (NOAO/AURA/NSF) and Hubble Heritage Team (STScI/AURA/NASA) Stars Forming in a Dynamic Interstellar Medium Alyssa A. Goodman Harvard-Smithsonian Center for Astrophysics cfa-

Core “Rotation”?? N 2 H + in TMC-1C; Schnee & Goodman 2003 FWHM Gradient “Beam” 0.1 pc

Core “Rotation”?? N 2 H + in TMC-1C; Schnee & Goodman 2003

Core “Rotation”?? N 2 H + in TMC-1C; Schnee & Goodman 2003

Core “Rotation”?? N 2 H + in TMC-1C; Schnee & Goodman 2003

SIRTF Legacy Survey Perseus Molecular Cloud Complex (one of 5 similar regions to be fully mapped in far-IR by SIRTF Legacy)

SIRTF Legacy Survey MIRAC Coverage 2 degrees ~ 10 pc

The Value of Coordination C 18 O Dust Emission Optical Image NICER Extinction Map Radial Density Profile, with Critical Bonnor-Ebert Sphere Fit Coordinated Molecular-Probe Line, Extinction & Thermal Emission Observations of Barnard 68 This figure highlights the work of Senior Collaborator João Alves and his collaborators. The top left panel shows a deep VLT image (Alves, Lada & Lada 2001). The middle top panel shows the 850  m continuum emission (Visser, Richer & Chandler 2001) from the dust causing the extinction seen optically. The top right panel highlights the extreme depletion seen at high extinctions in C 18 O emission (Lada et al. 2001). The inset on the bottom right panel shows the extinction map derived from applying the NICER method applied to NTT near-infrared observations of the most extinguished portion of B68. The graph in the bottom right panel shows the incredible radial-density profile derived from the NICER extinction map (Alves, Lada & Lada 2001). Notice that the fit to this profile shows the inner portion of B68 to be essentially a perfect critical Bonner-Ebert sphere