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Science With ALMA

Science With ALMA. T. L. Wilson European ALMA Project Scientist, and Interim JAO Project Scientist. Bilateral ALMA + ALMA Compact Array (in lower right). Location Chajntantor Plateau at 5000m in northern Chile. ALMA. ALMA Science Drivers. Key drivers: Detect the Milky Way at z=3

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Science With ALMA

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  1. Science With ALMA T. L. Wilson European ALMA Project Scientist, and Interim JAO Project Scientist ESO Seminar, 25 May 2006

  2. Bilateral ALMA + ALMA Compact Array (in lower right) ESO Seminar, 25 May 2006

  3. Location Chajntantor Plateau at 5000m in northern Chile ALMA ESO Seminar, 25 May 2006

  4. ALMA Science Drivers • Key drivers: • Detect the Milky Way at z=3 Measure dust broadband emission and spectral line radiation from atoms and molecules in high-z galaxies to obtain detailed morphology and kinematics • Protostars and planet formation: • Angular resolution of an AU at 150 pc (nearest molecular cloud); 10milli arc seconds • High Fidelity Images in Spectral Lines and Continuum ESO Seminar, 25 May 2006

  5. Simulation of a protostellar disk Jupiter-mass protoplanet around 0.5 solar mass star Orbital radius: 5 AU Maximum baseline: 10 km f = 850 GHz 8 hour integration 150 Light years 300 Light years ESO Seminar, 25 May 2006

  6. Sizes of the SPIRE and PACS beam sizes on the HDF north Field This shows the limits of Herschel angular resolution. Herschel measurements need follow ups with higher angular resolution imaging ESO Seminar, 25 May 2006

  7. Visible UV Infrared mm Add dust Intensity Wavelength ESO Seminar, 25 May 2006

  8. A Next Generation Millimeter Telescope A major step in astronomy  a mm/submm equivalent of VLT, HST, JWST, EVLA • Capable of seeing star-forming galaxies across the Universe • Capable of seeing star-forming regions across the Galaxy These Objectives Require: • An angular resolution of 0.1” at 3 mm • A collecting area of about 6,000 sq m • An array of antennas to obtain arc sec or better angular resolution • A site which is high, dry, large, flat since water vapor absorbs mm/sub-mm signals • A high Andean plateau is ideal ESO Seminar, 25 May 2006

  9. Summary of Requirements ESO Seminar, 25 May 2006

  10. Back End & Correlator Technical Building ANTENNA Correlator Front-End Tunable Filter Bank Local Oscillator IF-Processing (8 * 2-4GHz sub-bands) Digital De-Formatter Digitizer Clock Digitizer 8* 4Gs/s -3bit ADC 8* 250 MHz, 48bit out Optical De-Mux & Amplifier Data Encoder 12*10Gb/s Fiber Patch-Panel From 270 stations to 64 DTS Inputs 12 Optical Transmitters 12->1 DWD Optical Mux Fiber ESO Seminar, 25 May 2006

  11. Correlator Set Up: Four IF Bands of 2 GHz Each Can be Analyzed by 32 Filters, 16 in Each Polarization Region analyzed by a single spectrometer (we show ½ of the filters) 2 GHz wide IF Spectrometer is a recycling correlator: # of channels x total bandwidth=(128)x(2 GHz) ESO Seminar, 25 May 2006

  12. The ALMA FOV is 25” at 1 mm ALMA Receiver Bands ESO Seminar, 25 May 2006

  13. Sensitivity with 6 antennas ESO Seminar, 25 May 2006 Bands 3, 6, 7 and 9 are in bilateral ALMA

  14. Herschel and ALMA Science: The Cool Universe • Herschel is best suited for surveys, ALMA a follow-up instrument • ALMA has a small Field Of View (FOV), but high angular resolution and sensitivity • Higher angular resolution to image the sources measured by Herschel • Follow up to sources discovered with PACS or SPIRE in longer wavelength dust emission • Also, surveys in CO to determine redshifts ESO Seminar, 25 May 2006

  15. Herschel and ALMA Science Topics ISM in Galaxies: • Normal galaxies • Physical properties of star-forming ISM ISM in the Milky Way: • Structure • Dynamics (pressure) • Composition(gradients) Dense cores and star-formation: • Temperature, density structure • Dust properties • Stellar IMF Late stages of stellar evolution: • Winds • Shells • Asymmetries • Composition Solar System: • Water in GiantPlanets • Atmospheric chemistry • Water activity and composition of comets ESO Seminar, 25 May 2006

  16. Scientific Areas • High Redshift Galaxies and Cosmology • Active Galactic Nuclei & Star Formation in Galaxies • Star and Planet Formation • Water in the Universe • Astrochemistry in Hot Cores and Envelopes of Evolved Stars • Solar System ESO Seminar, 25 May 2006

  17. High Redshift Sources and AGN’s • High star formation rates, >>20 solar masses per year • Most of the radiation emitted by stars is absorbed by dust and re-radiated in the 3 micrometer to 1 mm wavelength range • The luminous IR galaxies trace regions where the concentration of galaxies is largest, and trace the formation of large scale structures. ESO Seminar, 25 May 2006

  18. AGN’s: Herschel & ALMA • Measure 1000’s of sources with PACS and SPIRE, then follow up with longer wavelength continuum data with ALMA • ALMA spectral line measurements of CO and other species • Herschel will sample the regime where most of the luminosity is radiated • High resolution images with ALMA allow a better determination of the size of emission sources ALMA would provide high resolution images to refine models. • Separate star formation and accretion in AGN’s • Could also make imaging survey of sources found with PLANCK ESO Seminar, 25 May 2006

  19. Image of the redshift z=6.4 source in CO line emission The CO emission was shown to be extended ESO Seminar, 25 May 2006

  20. CO Lines Observable with ALMA Receivers as a Function of Redshift ESO Seminar, 25 May 2006

  21. Normalized integrated CO line intensity With a number of CO line measurements one can determine physical parameters of a source ESO Seminar, 25 May 2006

  22. NGC6240-An AGN Case Study ESO Seminar, 25 May 2006

  23. Nearby Galaxies • Investigate star formation in other types of galaxies • At 10 Mpc, 0.1” is equivalent to 4.8 pc • Compare to models, in regard to the influence of nearby surroundings, metallicity, mergers ESO Seminar, 25 May 2006

  24. IC10-A Nearby Blue Dwarf Galaxy D=0.7 Mpc; Total size of the image is 10’ ESO Seminar, 25 May 2006

  25. Boxes show FOV of Bolometers. The FOV of ALMA at 3 mm is the circle in the lower left Smallest box is the integral field spectrometer In PACS ESO Seminar, 25 May 2006

  26. Star Formation in our Galaxy • We can study different stages of star formation in individual sources • We believe that the basic physical laws are understood but the relative importance of various effects is not known • The study of low mass star formation will allow us to understand how our solar system formed • In this study we group ‘protostars’ and ‘debris disks’ ESO Seminar, 25 May 2006

  27. Sketch of Protostar Development ESO Seminar, 25 May 2006

  28. 450/850 micrometer images of Fomalhaut. The contours are 13 and 2 mJy/beam. Below are deconvolved images (data from JCMT and SCUBA) ESO Seminar, 25 May 2006

  29. Dust Spectra and Herschel Bolometer Bands ESO Seminar, 25 May 2006

  30. Orion KL Spectrum from Ground ESO Seminar, 25 May 2006

  31. Orion KL: The Classical Hot Core Source Within a 20” region there are a variety of physical conditions ESO Seminar, 25 May 2006

  32. Heerschel HIFI Water Lines This transition in ALMA band 5 (a maser line) ESO Seminar, 25 May 2006

  33. Main Sequence & Evolved Stars • In broadband continuum, ALMA should be able to detect high mass stars in our Galaxy, and evolved stars even in the LMC • In evolved stars such as IRC+10216, ALMA will be able to image molecular and dust emission • Herschel can be used to search for water vapor in the envelopes of such stars ESO Seminar, 25 May 2006

  34. Sample spectra from IRC+10216 (R Leo), a nearby carbon star ESO Seminar, 25 May 2006

  35. Images of some molecules in IRC10216, a nearby carbon star ESO Seminar, 25 May 2006

  36. Solar System Objects • Herschel can easily measure outer planets, and moons of these planets, as well as Trans Neptune Objects • Highly accurate photometry • Water on the giant planets • Follow up would be HDO, to determine D/H ratio • ALMA and Herschel might be used to measure a common source at a common wavelength to set up a system of amplitude calibrators • ALMA provides high resolution image, but also records the total flux density ESO Seminar, 25 May 2006

  37. A Comparison of analysis schemes ESO Seminar, 25 May 2006

  38. Conclusions • Overall, Herschel is best suited for surveys, while ALMA a follow up instrument • ALMA has a small FOV, but high angular resolution and sensitivity • Higher angular resolution to image the sources measured or detected by Herschel • Also follow ups to PACS or SPIRE surveys in CO or in longer wavelength dust emission • Need common set of sources • In combining results we need well established calibrations • In analyzing the results, really need a much more sophisticated system • For planets, comets and asteroids can image in spectral lines and continuum ESO Seminar, 25 May 2006

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