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Thangasamy Velusamy

Photo of Thangasamy Velusamy


4800 Oak Grove Drive
M/S 169-506

Pasadena, CA 91109





Member of:

Interstellar and Heliospheric Physics


  • B.Sc, Physics, St.John's College (Madras University), Palayamkottai, India (1961)
  • M.Sc, Physics, Madras Christian College (Madras University), Madras, India (1964)
  • Ph.D, Astronomy, University of Maryland, College Park, Md (1973)

Professional Experience

  • Jet Propulsion Laboratory (1992-Present)
    • Principal Scientist, Astrophysics (2001-Present)
    • Research Scientist, Astrophysics (1995-2001)
    • NRC Senior Research Associate (1992-1995)
  • Tata Institute of Fundamental Research (TIFR), Bombay (1965-1992)
    • Professor & Director of Ooty Radio Observatory (1989-1992)
    • Research Associate/Reader/Associate Professor (1965-1988)
  • University of Maryland, College Park, MD
    • Research Associate (1979-1981)
    • Graduate Student & Research Assistant (1969-1973)
  • Radio Sterrenwacht Dwingeloo, The Netherlands, Visiting Scientist (Fall 1977)
  • Lawrence Livermore National Laboratory Livermore, CA, Visiting Scientist (Summer 1987 & 1989)
  • Department of Terrestrial Magnetism Carnegie Institution, Washington D.C, Visiting Scientist (Summer 1973)

Research Interests

  • Science support to GAVRT’s K-12 & citizen scientist programs - GAVRT operates two retired DSN antennas to monitor Jupiter’s radio emission, to produce daily radio maps of sun at four wavelengths and to observe the variability of black hole targets.
  • Star and planet formation - physical and chemical structure & evolution of molecular clouds, star-forming cores and protostellar disks- young stellar infall/outflows
  • High contrast imaging for direct detection of extrasolar planets - design and performance analysis of infrared nulling interferometers

Selected Awards

  • Team Award: "Center for Long Wavelength Astrophsyics Team", 2008
  • Team Award: "HiResTeam" for developing tool for HiRes Deconvolution of Spitzer IR images, 2004
  • Senior Research Associateship, National Research Council, 1992-1995
  • Atomic Energy Commission Merit Scholarship (M.Sc. Physics), 1962-64

Selected Publications


  1. RAY, A. & Velusamy, T., eds, "Supernovae and Stellar Evolution," Proc. Of International Workshop, Goa, 1989, World Scientific, Singapore (1991).

Papers, Chapters, and Articles

  1. K. Matuszewska , T. Velusamy , V. dumitroaie , J. Arballo , R. Dorcey , S. Han , E. Klopping , N. Kreuser-Jenkins , S. Levin , D. Santos-Costa (2022) “Variability of Jupiter’s Synchrotron Radiation: Goldstone Apple Valley Radio Telescope (GAVRT) Observations -II”, PASP, (accepted April, 25 2022)
  2. T. Velusamy, V. Adumitroaie, J. Arballo, S. M. Levin, P. A. Ries, R. Dorcey, N. Kreuser-Jenkins, J. Leflang, D. Jauncey, S. Horiuchi, ,(2020), “ Goldstone Apple Valley Radio Telescope Monitoring Flux Density of Jupiter's Synchrotron Radiation during the Juno Mission”, PASP, 132,4402V
  3. T. Velusamy, T. B. H Kuiper, S. M. Levin R. Dorcey, N. Kreuser-Jenkins, J. Leflang, (2020), Goldstone Apple Valley Radio Telescope Observations of 2012 Solar Eclipse: A Multi-wavelength study of cm-wavelength Gyroresonance Emission from Active Regions” PASP, 132, 4201V
  4. Velusamy, T., Langer, W. D., Goldsmith, P. F., & Pineda, (2017), Thermal Pressure in Diffuse H2 Gas Measured by Herschel [C II] Emission”, ApJ 838,165
  5. Velusamy, T.; Langer, W. D.; Goldsmith, P. F.; Pineda, J. L (2015) “Internal structure of spiral arms traced with [CII]: WIM, HI, and molecular emission lanes”, A&A 578, A135
  6. Langer, W. D.; Goldsmith, P. F.; Pineda, J. L.; Velusamy, T.; Requena-Torres, M. A.; Wiesemeyer, H., (2015) “Ionized gas at the edge of the central molecular zone”, A&A 576, 1L
  7. Velusamy, T. & Langer, W. D. (2014) “Origin and z-distribution of [CII] mission from Galactic diffuse and ionized gas”, A&A, 572A, 45V
  8. Langer, W. D.; Pineda, J. L.; Velusamy, T, (2014) “The scale height of gas traced by [CII] in the Galactic plane”, A&A 564, A101.
  9. Velusamy, T.; Langer, W. D.; Thompson, T.(2014) “HiRes Deconvolved pitzer Images of 89 Protostellar Jets and Outflows: New Data on the Evolution of the Outflow Morphology”, ApJ 783, 6v.
  10. Langer, W. D.; Velusamy, T.; Pineda, J. L.; Willacy, K.; Goldsmith, P. F.(2014), “A Herschel [C ii] Galactic plane survey. II. CO-dark H2 in clouds”, A&A 561, 122.
  11. Pineda, J. L.; Langer, W. D.; Velusamy, T.; Goldsmith, P. F., (2013) “A Herschel [C ii] Galactic plane survey. I. The global distribution of ISM gas components”, A&A, 554, 103.
  12. T. Velusamy, W. D. Langer, J. L. Pineda, P. F. Goldsmith, (2012) [CII] 158 micron line detection of the warm ionized medium in the Scutum-Crux spiral arm tangency, A&A (Lett) 541, L10.
  13. T. Velusamy, W. D. Langer, M. S. N. Kumar, J. M. C. Grave, (2011) Jets and Wide-angle Outflows in Cepheus E: New Evidence from Spitzer, ApJ, 741, 60.
  14. T. Velusamy, W. D. Langer, J. L. Pineda, P. F. Goldsmith, D. Li, H. W. Yorke, (2010) [CII] Observations of H2 Molecular Layers in Transition Clouds, A&A 521, 18.
  15. P. F. Goldsmith, T. Velusamy, D. Li, W. D. Langer, (2010) Molecular Hydrogen Emission from the Boundaries of the Taurus Molecular Cloud, ApJ, 715, 1370.
  16. T. Velusamy and W. D. Langer, (2008) Polycyclic Aromatic Hydrocarbon and H2 Emissions in the Ultraviolet-Dominated Region in NGC 2316, AJ 136, 602.
  17. T. Velusamy, R. Peng, D. Li, P. F. Goldsmith, W. D. Langer, (2008) Dichotomy in the Dynamical Status of Massive Cores Orion, ApJ (Lett) 688,L 87.
  18. Velusamy, T., Marsh, K.A., Beichman, C.A., Backus, C.R., (2008) "HiRes Deconvolution of Spitzer IR images", AJ 136, 197.
  19. T. Velusamy, W. D. Langer, K. A. Marsh, (2007) Highly Collimated Jets and Wide-Angle Outflows in HH 46/47: New Evidence from Spitzer Infrared Images, ApJ (Lett) 668, L159.
  20. D. Li, T. Velusamy, P. F. Goldsmith, W. D. Langer, (2007) Massive Quiescent Cores in Orion II. Core Mass Function, ApJ, 655, 351.
  21. Marsh, K. A.; Dowell, C. D.; Velusamy, T.; Grogan, K.; Beichman, C. A. (2006) "Images of the Vega Dust Ring at 350 and 450 µm: New Clues to the Trapping of Multiple-Sized Dust Particles in Planetary Resonances", ApJ (Lett) 646, L77.
  22. Marsh,K.A.; Velusamy,T.; Dowell, C.D.; Grogan,K.; Beichman,C.A. (2005) "Image of Fomalhaut Dust Ring at 350 Microns: The Relative Column Density Map Shows Pericenter-Apocenter Asymmetry", ApJ (Lett) 620, 47.
  23. Takeuchi,Taku; Velusamy,T.; Lin,D.N.C. (2005) "Apparent Stellar Wobble by a Planet in a Circumstellar Disk: Limitations on Planet Detection by Astrometry ", ApJ, 618,987.
  24. Lai, S-P., Velusamy, T., & Langer, W.D. (2003) "High Angular Resolution Study of the Ion and Neutral Spectra as a Probe of the Magnetic Field Structure," ApJ (Letters), 596, L239.
  25. Velusamy, T., Angel. R.P., Eatchel, A., Tenerelli, D., & Woolf, N.J. (2003) "Single and Double Bracewell Nulling Interferometry in Space," in Proc. "Towards Other Earths," ESA SP-539, p631.
  26. Lai, S-P., Velusamy, T., Langer, W. D., & Kuiper, T.B.H., (2003) "Physical and Chemical Status of Prestellar Core B68," Astron J. 126, 311.
  27. Velusamy, T., Langer, W. D., & Goldsmith, P. F. (2002) "Tracing the Infall and the Accretion Shock in the Protostellar Disk: L1157," ApJ (Letters), 565, L43.
  28. Velusamy, T., & Langer, W.D., (1998) "Outflow-Infall Interactions as a Mechanism for Terminating Accretion in Protostars," Nature, 392, 685.
  29. Velusamy, T., Kuiper, T. B. H. & Langer, W. D. (1995) "Imaging Infall: CCS observations of the protostellar envelope of B335." ApJ (Letters), 451, L75.
  30. Velusamy, T. (1984), "Radio detection of a jet in the Crab Nebula," Nature, 308..251.