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Why, How, and How we Figure Out Where New Stars Form

Why, How, and How we Figure Out Where New Stars Form. Alyssa A. Goodman Harvard-Smithsonian Center for Astrophysics cfa-www.harvard.edu/~agoodman. Intensity. "Velocity". Extinction. Glossary for Alyssa Goodman’s Talk 12/12/02.

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Why, How, and How we Figure Out Where New Stars Form

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  1. Why, How, and How we Figure OutWhere New Stars Form Alyssa A. Goodman Harvard-Smithsonian Center for Astrophysics cfa-www.harvard.edu/~agoodman

  2. Intensity "Velocity" Extinction Glossary for Alyssa Goodman’s Talk 12/12/02 Extinction--the degree of “blackness” on the sky caused by dust between background objects and an observer Emission--photons produced by some physical process Absorption--removal of photons by some physical process Spectral line--emission or absorption over a very narrow wavelength range, caused by a change in the quantum mechanical state of a particular atom or molecule Emission Spectral line

  3. Star Formation (a.k.a. GMC or Cloud Complex)

  4. Barnard’s Interstellar Medium

  5. Counts of stars per unit area measure how much material must be producing obscuration, gives “extinction.” “Barnard’s Method”: Star Counting Observations by Alves, Lada & Lada 1999

  6. Barnard’s Interstellar Medium

  7. 80 years after Barnard

  8. 80 years after Barnard

  9. HST, IRAS (Earth Orbit) SIRTF (Sun Orbit) Telescopes Used in Our Mapping of the ISM Nagoya 4-m (Japan) FCRAO & CfA (Mass.) IRAM 30-m (Spain) JCMT (Hawaii) Arecibo (Puerto Rico) KPNO 12-m & HHT (Arizona) NTT, VLT (Chile) ATCA+Parkes (Australia)

  10. Dust Emits, as well as Absorbs, Photons Barnard’s Optical Photograph of Ophiuchus IRAS Satellite Observation, 1983 Remember: Cold (10K) dust glows, like a blackbody, in the far-infrared.

  11. Absorption, Scattering, Emission & Extinction Absorber “Absorption” Scatterer “Scattering” Emitter “Emission” Note: Absorption + Scattering = “Extinction”

  12. Multiwavelength Milky Way O

  13. Thermal Dust Emission in the OrionStar-Forming Region

  14. Absorption, Scattering, Emission & Extinction Absorber “Absorption” Scatterer “Scattering” Emitter “Emission” Note: Absorption + Scattering = “Extinction”

  15. Wavelength Dependence of Extinction short wavelength, e.g. optical Light is “Extinguished” & Does not Reach Us “Dust Grain” long wavelength, e.g. near-IR Light Goes Right by & Reaches Us “Dust Grain”

  16. Bok Globule (Core)

  17. Optical Seeing “through” the Clouds Near-Infrared

  18. Optical Image C18O Dust Emission Radial Density Profile, with Critical Bonnor-Ebert Sphere Fit NICER Extinction Map B68 obscuring, glowing & moving Extinction Emission from Glowing Dust Emission from Molecular Gas 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 C18O 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

  19. Pillars of Creation Contours show Molecular Spectral-Line (CO) Emmission M. Pound 1998

  20. Molecular Clouds: Where Stars Form The Oschin telescope, 48-inch aperture wide-field Schmidt camera at Palomar Red Plate, Digitized Palomar Observatory Sky Survey

  21. Radio Spectral-line Observations of Interstellar Clouds

  22. Tutorial:Velocity from Spectroscopy Observed Spectrum Telescope  Spectrometer 1.5 1.0 Intensity 0.5 0.0 -0.5 All thanks toDoppler 100 150 200 250 300 350 400 "Velocity"

  23. Tutorial:Velocity from Spectroscopy Observed Spectrum Telescope  Spectrometer 1.5 1.0 Intensity 0.5 0.0 -0.5 All thanks toDoppler 100 150 200 250 300 350 400 "Velocity"

  24. Radio Spectral-line Observations of Interstellar Clouds

  25. Radio Spectral-line Observations of Interstellar Clouds Radio Spectral-Line Survey Alves, Lada & Lada 1999

  26. Velocity as a "Fourth" Dimension Loss of 1 dimension No loss of information

  27. "Cores" and Outflows 1 pc Molecular or Dark Clouds Jets and Disks Extrasolar System Utility of Velocity Information Star Formation 101 Studies of Cloud Turbulence Studies of Infall, Outflow & Rotation Studies of Disk & Jet Motions Detection of Planets by Variations in Star’s Velocity

  28. 1950 1960 1970 1980 1990 2000 8 10 4 10 7 10 N 6 channels, 10 channels 3 10 *N N 5 10 channels pixels S/N in 1 hour, 2 10 4 10 (S/N)*N N 3 10 1 N 10 pixels pixels 2 10 0 10 1950 1960 1970 1980 1990 2000 Year Molecular Spectral Line Mapping Product That’s a one-thousand-fold “improvement” in 20 years. S/N

  29. "Cores" and Outflows 1 pc Molecular or Dark Clouds Jets and Disks Extrasolar System Star Formation 101

  30. “Giant” Outflows See references in H. Arce’s Thesis 2001

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

  32. PV CephEpisodic ejections from a precessing or wobblingmoving source Goodman & Arce 2002

  33. PV Ceph is moving at ~10 km s-1 Goodman & Arce 2002

  34. Truth?: Part 1

  35. Part II

  36. Star Formation >>101 • MHD turbulence gives “t=0” conditions; Jeans mass=1 Msun • 50 Msun, 0.38 pc, navg=3 x 105 ptcls/cc • forms ~50 objects • T=10 K • SPH, no B or L, G • movie=1.4 free-fall times Bate, Bonnell & Bromm 2002

  37. Molecular Line Map 2MASS/NICER Extinction Map of Orion Johnstone et al. 2001 Johnstone et al. 2001 Nagahama et al. 1998 13CO (1-0) Survey Putting in All Together: The “Uncoordination” Problem Lombardi & Alves 2001

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

  39. The SIRTF Legacy Survey SIRTF’s1st Plan forStar-FormingRegions “From Molecular Cores to Planet-Forming Disks” Neal J. Evans, II, Principal Investigator (U. Texas) Lori E. Allen (CfA) Geoffrey A. Blake (Caltech) Paul M. Harvey (U. Texas) David W. Koerner (U. Pennsylvania) Lee G. Mundy (Maryland) Philip C. Myers (CfA) Deborah L. Padgett (SIRTF Science Center) Anneila I. Sargent (Caltech) Karl Stapelfeldt (JPL) Ewine F. van Dishoeck (Leiden)

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

  41. 2 degrees ~ 10 pc SIRTF Legacy Survey MIRAC Coverage

  42. 5 degrees (~tens of pc) SIRTF Legacy Coverage of Perseus COMPLETE, Part 1 Observations: 2003--Mid- and Far-IR SIRTF Legacy Observations: dust temperature and column density maps ~5 degrees mapped with ~15" resolution (at 70 m) 2002-- NICER/2MASS Extinction Mapping: dust column density maps ~5 degrees mapped with ~5' resolution 2003-- SCUBA Observations: dust column density maps, finds all "cold" source ~20" resolution on all AV>2” 2002-- FCRAO/SEQUOIA 13CO and 13CO Observations: gas temperature, density and velocity information ~40" resolution on all AV>1 Science: • Combined Thermal Emission data: dust spectral-energy distributions, giving emissivity, Tdust and Ndust • Extinction/Thermal Emission inter-comparison: unprecedented constraints on dust properties and cloud distances, in addition to high-dynamic range Ndust map • Spectral-line/Ndust Comparisons Systematic censes of inflow, outflow & turbulent motions enabled • CO maps in conjunction with SIRTF point sources will comprise YSOoutflow census >10-degree scale Near-IR Extinction, Molecular Line and Dust Emission Surveys of Perseus, Ophiuchus & Serpens

  43. FCRAO N2H+ map with CS spectra superimposed. COMPLETE, Part 2(2003-5) (Lee, Myers & Tafalla 2001). <arcminute-scale core maps to get density & velocity structure all the way from >10 pc to 0.01 pc 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 N2H+ 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)

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

  45. 2 pc COMPLETE Preview:Discovery of a Heated Dust Ring in Ophiuchus Goodman, Li & Schnee 2003

  46. 2 pc …and the famous “1RXS J162554.5-233037” is right in the Middle !?

  47. The “COMPLETE” Truth about Star Formation, c. 2005 Statistical Evaluation of Outflows’ Role Evaluation of Constructive/Destructive Role of Explosions/Winds Tracking down progeny

  48. Why, How, and How we Figure OutWhere New Stars Form Alyssa A. Goodman Harvard-Smithsonian Center for Astrophysics cfa-www.harvard.edu/~agoodman

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