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Radio Astronomy at Cornell

Radio Astronomy at Cornell. Faculty: Don Campbell asteroids, comets, planets, radar techniques Jim Cordes compact objects, interstellar medium, SETI Riccardo Giovanelli galaxies & large-scale structure of the universe Paul Goldsmith molecular clouds, star formation, instrumentation

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Radio Astronomy at Cornell

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  1. Radio Astronomy at Cornell Faculty: Don Campbell asteroids, comets, planets, radar techniques Jim Cordes compact objects, interstellar medium, SETI Riccardo Giovanelli galaxies & large-scale structure of the universe Paul Goldsmith molecular clouds, star formation, instrumentation Martha Haynes galaxies & large-scale structure of the universe Yervant Terzian interstellar medium, planetary nebulae, binary galaxies

  2. Radio Astronomy at Cornell Students & Postdocs: 10 graduate students doing research with a major radio/radar astronomy component International collaborations using all available astronomical resources 2 postdocs (extragalactic science, pulsars, masers, the Square Kilometer Array Undergraduates regularly work in radio research groups (observing trips to Puerto Rico, Palomar, etc., conferences, co-authoring papers, overall participation in the scientific enterprise)

  3. Other Facilities Essentially all major radio facilities in the world VLA, VLBA, GBT, FCRAO (mm), Parkes, Goldstone (DSN) Optical observatories (Palomar) Space observatories GRO, HST, SWAS, Chandra, SIRTF, GLAST Computational: > 100 CPUs in SSB (solaris/linux/wintel) Cornell Theory Center (~120 nodes)

  4. The Green Bank Telescope (WVa.)

  5. PSR B0919+06 S. Chatterjee et al. (2000)  = 88.5  0.13 mas/yr  = 0.83  0.13 mas VLBA Astrometry D = 1.2kpc V = 505 km/s

  6. Radar detection of ice deposits on Mercury Don Campbell + Arecibo collaborators + students

  7. 216 Kleopatra(main-belt asteroid ~217 x 94 km) 1999 JM8 = Earth Crossing Asteroid

  8. Surface quantities Pulsar B  1012 Gauss gNS 1011 g FEM  109 gNS mp   1013 volts

  9. Bound & Escaping NS Populations B2224+65 > 1000 km/s B1957+20 ~ 100 km/s J0437-4715 ~ 90 km/s H

  10. Extragalactic GroupCounterrotating Disks in Galaxies: Dwarf galaxies: abundances, morphology, star formation

  11. Other Extragalactic projects • Studies of the local reference frame with respect to large-scale structure • Combined HI, IR and optical studies of galaxies (rotation curves, morphology) • OH megamasers as a powerful method for quantifying star formation vs. redshift (Jeremy Darling PhD thesis)

  12. Molecular Line Studies • Contents of molecular clouds in star-forming regions (CO and HI relationship) • Chemistry of molecule production in clouds • SWAS (Submillimeter Wave Astronomy Satellite): evidence for comet destruction in envelope of red-giant star.

  13. Planetary Nebulae & White Dwarfs Nature of bipolarity Motion of shells Energetics

  14. Parkes MB Feeds

  15. ALFA = Arecibo L-band Feed Array(1.4 GHz) • Cornell faculty, students heavily involved • Instrumentation, software, science planning, surveys • Major surveys to commence in early 2005 • International science consortia • Pulsars • Galactic science • Extragalactic science • SETI

  16. ALFA Surveys • Deep pulsar surveys • ~1000 new pulsars • NS-NS, NS-BH binaries • Submillisecond pulsars • Galactic plane hydrogen surveys • Phase structure of the ISM • Supershells and chimneys • High-velocity clouds (tidal debris vs. primordial) • Extensive surveys for galaxies • Zone of avoidance • Low mass galaxies • SETI • Deepest survey of the Galactic plane ever done

  17. The Square Kilometer Array • International project • Substantial Cornell involvement • 20x sensitivity of Arecibo • Will look like the VLA + VLBA (e.g. 5000 12-m antennas) • > 2010! • Prototypes expected in this decade • Growing involvement of NAIC with the SKA and related projects • Opportunities for undergraduate participation

  18. China KARST Canadian aerostat US Large N Australian Luneburg Lenses Dutch fixed planar array Current Concepts (cf. Allen Telescope Array, Extended VLA) Also cylindrical reflectors (cf. LOFAR = Low Freqency Array)

  19. Radio Astronomy at Cornell Students & postdocs: 10 graduate students doing research with a major radio/radar astronomy component Multiwavelength (radio to gamma-rays) Collaborations with other departmental groups (IR, theory, planetary) Multi-institution collaborations 2 postdocs at present working on extragalactic science, pulsars, masers and the Square Kilometer Array

  20. Recent VLBI

  21. Extragalactic GroupCounterrotating Disks in Galaxies Dwarf galaxies: abundances, morphology, star formation

  22. Studies of the Tully-Fisher Relation and Peculiar Velocities in the Local Universe

  23. Surveys with Parkes, Arecibo & GBT. Simulated & actual Yield ~ 1000 pulsars.

  24. REMOTE SENSING THE UNIVERSEWITH RADIO WAVESJim Cordes, Cornell University 9 June 2001 • The sky at different wavelengths • Advantages of radio astronomy • What do we see? • New surveys with the upgraded Arecibo Telescope • The Square Kilometer Array

  25. THE MILKY WAY optical

  26. THE MILKY WAY optical Andromeda (M31)

  27. THE MILKY WAY optical infrared

  28. THE MILKY WAY Radio (408 MHz X-rays

  29. Advantages of Radio Sensing • The Galaxy and the universe are mostly transparent to radio waves (except when the U. was younger than 300,000 yr) • The radio sky looks very different than other wavelengths • Some objects in the universe appear only as radio objects.

  30. Surface quantities Pulsar B  1012 Gauss gNS 1011 g FEM  109 gNS mp   1013 volts

  31. The Very Large Array (New Mexico) Arrays of antennas are used to make radio images of the sky

  32.  Radio Galaxy

  33. PSR B0919+06 S. Chatterjee et al. (2001)  = 88.5  0.13 mas/yr  = 0.83  0.13 mas Very Long Baseline Array D = 1.2kpc V = 505 km/s

  34. Parkes MB Feeds

  35. Surveys with Parkes, Arecibo & GBT. Simulated & actual Yield ~ 2000 pulsars.

  36. China KARST Canadian aerostat US Large N Australian Luneburg Lenses Dutch fixed planar array Square Kilometer Array Current Concepts (cf. Allen Telescope Array, Extended VLA) (cf. LOFAR = Low Freqency Array)

  37. SKA pulsar survey 600 s per beam ~104 psr’s

  38. Forks in the Road supernova nada prompt black hole neutron star other? neutron stars fallback black hole canonical pulsar (1012 G) NS magnetar, SGR (1015 G) other

  39. Chandra image of Cass A No periodicity or single pulses detected (McLaughlin et al. 2000) PSR 0355+54 Cass A

  40. Neutron Stars Background: 1932: neutron discovered 1933: neutron stars (Baade & Zwicky) l939: first models (Oppenheimer & Volkoff) Detectability? Thermal (106 K, 10 km)  bleak 1967: Radio pulsars (serendipitous) Gamma-ray bursts (ditto) 1968: Pulsar discovery announced Crab pulsar discovered 1969: Crab pulsar spindown measured & clinched the NS hypothesis (T. Gold)

  41. Manifestations of NS • Rotation driven: • “radio” pulsars (radio   rays) • magnetic torque (Edot  Idot  I B2 4 ) •   e+ e- + plasma instability  coherent radio • Accretion driven: • X-rays Lx =  Mdot c2 • LMXB, HMXB • Magnetic driven? Crustquakes? • Magnetars (AXPs, SGRs) • Spindown … but Lx > Edot • Gravitational catastrophes? • Gamma-ray bursts, G.wave sources, hypernovae?

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